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kitsuneyoukai

Solar Power Question again! :b

by
'i am once again asking... if you have any heckin idea what's wrong with this solar array we're using'
because my family is going nuts trying to figure this problem out!

'Battery Capacity Draining Too Fast'

we just recently doubled our batteries, half old (oldest being 3 years), and half being 3 months old
100AH deep cycle marine batteries

and even after having done that, we're still running outta power at just about dawn.
we're going from 26-25.5 volts all the way down to 22.5-23 volts by drawn , OR outright dying. drawing only 700-1000 watts! =l with a total 36 of these batteries...

but by the math we've repeatedly checked, we should have 43200 watts in total, which should be like 30 hours all on its own even if we got no sun, right?

just today we had charged up the system all on its own, nothing draining it, to insure it was truly full, it reaches 28.8. good. we then hook it back up and draw power, and by like 6pm, its down to 25.1 all monitors roughly indicate and then by now at 1am, its 24 volts... and we're only using half of what we want to... and if we did run it at the aprox 1500-2000 watts we want, it'd surely be dead by morning...

so where is all of our added capacity going? adding more, and fully charging it to where it stopped putting in more power, didnt help it seems...

and we're making 5000 watts ATLEAST, up to 6000 maybe more on really good days.

so if someone could explain or theories why we're getting like 1/3rd of the capacity we're pretty sure we should be getting, that'd help alot :v


so to rehash... we should/expect like 43200 watts, and then just draining 700-800, over like 10 hours, its almost dead.

(i hope i explained the situation correctly x.x im not the project lead on this =T and electricity scares the fur off me =b)

rough and slightly out of date illustration of the set up:
https://media.discordapp.net/attachments/59717436834211...
irl picture1: https://drive.google.com/open?id=1KZxBSVvcRXN0_GsQ9Oteq...
irl picture2: https://drive.google.com/open?id=19H8uKophDhkB5AsBpd0nM...
irl picture3: https://drive.google.com/open?id=1W05UPtNw22AcayI_bZXc9...

system stats:
grid type: isolated/offgrid
wire thickness: -2 gauge (between batteries and going to inverter)
voltage type: 24 volt
solar charge controllers: epever 40A MPPT solar charge controller
battery pattern: 'series/parallel' but scaled up to 2 rows of 18 batteries
inverter type: i believe its this one 'EDECOA 24V Pure Sine Wave Power Inverter 3500W'
battery type: 100AH deep cycle marine batteries

---
my last stupid problem seems to of not been a Hz problem at all, just a bad battery backup unit =T
Viewed: 325 times
Added: 4 years, 10 months ago
 
129 Comments on this Journal
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KevinSnowpaw
KevinSnowpaw
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
could it be a retention issue? like the batterys are bleeding power? is it very cold were you are presently? if you store the batteries on concrete that can also leech out power.. but i dont know much about your set up
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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i wish it was cold :l no its pretty warm in florida =V, half of the batteries are warm though, being about 85-90 degrees, specifically the older ones. BUT we just added new ones, and having done so, and gaining no significant capacity added, is fucking baffling!
KevinSnowpaw
KevinSnowpaw
4 years, 10 months ago
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hmm Solar is sadly a super inefficent form of energy at least presently. maybe your not generateing as much as you though so your not filling up the batterys? are you able to check the power contained in each battery after a full days charge? I know your allready ware that sun conditions will have a major impact on it to.


I wish i knew more about solar power and your set up im just tossing out sugestions.
NyotaMwuaji
NyotaMwuaji
4 years, 10 months ago
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Where in Florida? I also live in Florida and have some insight.
Omegaltd
Omegaltd
4 years, 10 months ago
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You're in Florida too??
Feryl
Feryl
4 years, 10 months ago
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We're all in Florida. >.<
Shippo
Shippo
4 years, 10 months ago
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Yep!
Feryl
Feryl
4 years, 10 months ago
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Wait...you too?!?!
Omegaltd
Omegaltd
4 years, 10 months ago
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I am on the NW side of Orlando.
Feryl
Feryl
4 years, 10 months ago
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Jax here. ^.^
Nightcrome
Nightcrome
4 years, 10 months ago
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So oh wow I work in jax
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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seems no one is in lake city =T ... good :l this town is a black hole where no one escapes o3o
Feryl
Feryl
4 years, 10 months ago
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Here in Jax we almost consider Lake City a part of the suburbs. >.< Only like a 45 minute drive from my house, I live on the west end of Duval.
Shippo
Shippo
4 years, 9 months ago
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Yep! I’m west of Orlando in the Clermont area.
esanhusky
esanhusky
4 years, 10 months ago
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Try disconnecting a few batteries at a time and see what it does.  If you have a short in one of them, it could cause excessive drain
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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we've tried seperating the batteries into 2 segments/cells, and that didnt cause much difference if i recall =o but maybe.
SuperBH
SuperBH
4 years, 10 months ago
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Possibly the panels need cleaning? If they're not fully exposed then the charge time will be longer and obviously less power will be produced.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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production is fine, we charged up till the controllers all stopped putting in power, and it acts the same way as if we hadn't fully charged it intentionally =l
zyfer
zyfer
4 years, 10 months ago
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You live in Aussieland right?
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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nope, north florida :v just up very late =T as usual, lol.
zyfer
zyfer
4 years, 10 months ago
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ideas - maybe the humidity is weaking/leeching power...
maybe you have something going to ground?

43K watts storage, 5000 watts in, How much power out? 2K?
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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we want atleast 1.5k going out, at most 2k pretty much
ThaPig
ThaPig
4 years, 10 months ago
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Have you performed the right propitiation rituals to gain the favor of Ra before obtaining his power?
Resua
Resua
4 years, 10 months ago
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You probably have faulty batteries in the pack somewhere.  The pack needs to be charged to full, and broken down into the series pairs, then left to sit for 6, 12, and 24 hours.  Look for the batteries that are self discharging, and remove them from service.  One bad battery will rapidly bring the pack down far more than it should, converting electricity into heat.  You cannot do it effectively while the pack is assembled, as other pairs will cover up the unhealthy ones.  Those kinds of batteries must also be regularly serviced and watered.  They cook off their water when they charge.  Those flat screw-caps have to be removed and the water checked, monthly, in this kind of service.  They must be filled with distilled water without readded minerals to the proper level regularly.

Your solar chargers are also going to have issues with equalization, etc.  All controllers should have equalizing charge disabled and equalization manually done, as i doubt those epever controllers can sync equalization.  If one controller has enough oomph to equalize the pack, then set one to do it, usually whichever one has the most power towards the end of the day.  But a pack that big, I dont think those 40 amp controllers will swing it.

Are you measuring the amps of DC draw at the pack, vs rated capacities and whatnot on the AC side to get your watt numbers?  inverter inefficiencies add up, FAST.

This kind of setup is also why larger batteries are made.  This pack (24V@1800ah) would probably be more reliable, and better serviced, with 12 trojan SIND 02 2450s.  I have around 15 years life out of mine in a similar config, and they are about to be replaced, but still make 80% of their rating.  Granted, that's ~8000 dollars worth of batteries
HuskaIshelwood
HuskaIshelwood
4 years, 10 months ago
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You're slightly wrong. with a multimeter you can touch the terminals of each battery in the pack, and not the straps that put them in series/parallel, you can individually read each battery that way without disassembly of the pack as a whole.

My suggestion, have an alternative means of power so you can have power on demand when the sun isn't around. It's less then ideal, sure, but it also means when you have a bad battery you can dump power into it so you can go through and find the battery(s) with bad cells. Remove them from the array and replace them with new batteries.

Keep a good 5kW diesel generator on the system that can act as emergency back up power for those long cloudy days where the solar may not make enough juice to keep the house going. Also, how old is the Solar array? As Solar panels age the power they produce diminishes, it is possible you aren't making as much power as you thought you're making. (It could be a small difference, maybe 4.8kW instead of 5kW, So it doesn't charge your batteries as quick but quickly enough to make it seem like they are working normally.)
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
PLEASE NOTE that his inverter and charge controllers CANNOT accept input from wind or a generator anywhere in the system.
So he would need to build a whole new system to add a genny.
This is why I reccomended a grid-tie or hybrid grid-tie/BESS system.
HuskaIshelwood
HuskaIshelwood
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
That is also fundamentally wrong, Many charge controllers have other inputs for wind or fuel generators, and a more advanced one can even have a start control for a fuel generator that it'll turn said generator on when power in the batteries gets too low and there isn't enough power coming in from the solar panels.

You can see multiple people doing the 'off the grid' living, and having multiple power sources because you need to have backups and backups for your backups so that if you get a few really bad overcast days you're not completely fubar on power.

Edit: I would like to make an edit to state, that you could T into the power intake from the solar panels, put a high power diode on each line to regulate which direction the power can flow, and put a backup generator on the same intake line the Solar panels come into.

Solar panels don't make special magical electricity, if you use the same voltage and amperage, you can put any power intake through the same lines and it can't tell the difference in source. The use of diodes are commonly used to make one direction electricity flow. A *emergency* generator, should only be on when the solar panels are not making enough power, or any power, and you need a boost from another source - not a part of the general power system.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
You're misreading.  I said HIS system, as in the equipment he currently owns, cannot support wind or generators on them.

Many such systems do exist, but he does not currently have the equipment.

Even if it was diode regulated, it would effectively disable the MPPT functionality and force it to act like a PWM.  The manufacturer docs specifically state that it isn't to be used with such, or microinverters either.

Growatt makes some bi-way and tri-way hybrid systems that support Wind, Gen, and Solar (up to 2 arrays) input at 400V max PV, 360v max Gen and Wind, IIRC.  They also support two seperate battery arrays, grid-tie, and BESS expansion.  Expensive but absolutely amazing for modularity.
HuskaIshelwood
HuskaIshelwood
4 years, 10 months ago
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Another point, in a second post because I couldn't edit my first post a second time apparently.

If you were concerned about overvoltage/overamperage on the charge controller with two generators (Solar,Fuel) on the same system, you could install a disconnect on the Solar panel *and* generator side, so that you can cut the connection from either generator and ensure only one can make it into the system. Again, the suggestion to add a fuel generator is literally just as a emergency point, when you run out of power and your solars aren't making enough, or if for some reason your solars get damaged.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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they apparently can, wired in separate =v
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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my brother sadly has no significant comments about what you said, but took it into account =o

question though, given the materials at hand, what pattern would you suggest we use for the batteries?
Resua
Resua
4 years, 10 months ago
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With what you have on hand, there's not much you can change with how the batteries are laid out or improve the efficiency.  A system that large should really be 48v nominal to boost efficiency, but you'd have to replace all the charge controllers and the inverters, and probably most anything connected via dc.  The battery health just needs to be verified, as its quite likely there are bad batteries in the pack.  Maintenance needs to be done (batteries watered till the plates are covered) regularly to extend their life.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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we just watered all the batteries like 2 days ago. the cells toward the outside were the most drained, meaning presumable the cells in the middle arent getting used as much or at all, right? =l
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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but really? =o no pattern suggestion? =x hmm... dang... well we hope one of these arrangments is even working at all, much less being best efficiency

https://cdn.discordapp.com/attachments/5971743683421143... new

https://cdn.discordapp.com/attachments/5971743683421143... previous
whitepawrolls
whitepawrolls
4 years, 10 months ago
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Any "leach" devices left plugged in like chargers etc? Possibility of resistance in the wires draining current? Try turning everything off, measure the current at the batteries to see if something is still pulling. Then turn things on one at a time to see if something is pulling more than it should, or a high use item. Last thing I can think of (as its way past bedtime here) is what are the batteries sitting on? Sitting on the ground or connected to it could possibly drain them too if I remember right.
Omegaltd
Omegaltd
4 years, 10 months ago
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It is not a good idea to mix old and new batteries.
There could be a short circuit somewhere.
Power usage may be exceeding the battery capacity.
weather conditions affect battery conditions.
Electrical contacts oxidize and may need cleaning.
Electrical contacts could be corroding if batteries are acid based and leaking.
VK102
VK102
4 years, 10 months ago
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Maybe you guys have a leak in the wiring of the house?
Like, some exposed wire connected to ground someway?
blindrabbit
blindrabbit
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Are your charge controllers able to charge the load thats placed on them?  Sounds like along with mixed batteries you might want to look at the charge controller...  are you getting current from it? is the voltage correct?

Whats simple is buried ..it can be hell to find..  I have seen things as simple as oxidation cause as much as 50% drop in current,, along with wire size,,,

arlasser
arlasser
4 years, 10 months ago
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" blindrabbit wrote:

Whats simple is buried ..it can be hell to find..  I have seen things as simple as oxidation cause as much as 50% drop in current,, along with wire size,,,



it's true that oxidation don't help but if there is some the best thing to do is replace that faston with one new
blindrabbit
blindrabbit
4 years, 10 months ago
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Very true.. I also seen cables where corrosion wicked inside the jacket and ate away the copper wire inside,, looks prtfrvt on outside,, nothing in the inside..
Chrisicefallenmoon
Chrisicefallenmoon
4 years, 10 months ago
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Kitsune is that the exact batteries your using if so i know the problem tour using a 12 amp battery on a 24 amp system therefor every battery only holds half the time held within
arlasser
arlasser
4 years, 10 months ago
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by the scheme shown the batteries are positionated in couple so the voltage applied at couple of batteries is 24V
Chrisicefallenmoon
Chrisicefallenmoon
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Yes but still only a single output point so it is still pulling 24 from a 12 the input and output batteries should be the same amperage to prevent extra strain on the batteries that would cause them to drain quicker
NeroServal
NeroServal
4 years, 10 months ago
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Hello, I’ve been off-grid and work with systems all the time. A couple things I noticed point to your problem or potential problem. First is mixing old and new batteries, the temperature and location and your capacity. If you have older batteries in Florida (high temperatures) and they get used daily you usually only get 2-5 years max out of them. I lived there for a few years. If possible try to keep the batteries in temps between 50°F and 80°F to increase their life drastically. At high temperatures they deteriorate much faster. Second never mix old with new if possible since failing batteries will keep stealing power from your new batteries ruining them way faster than normal. Also are you going off the rated capacity on the batteries or half the rate? Lead acid have only half of their rated capacity or your bringing them well below their health voltage. Direct message me for more info and I can help more with the problem. Thanks
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
This

Noone talks about lead-acid having only 50% or less capacity (~30% for car starters, ~40% for marine, and ~50% for proper deep-cycle gels.  ~70% for silicon-sla!  Silicon-SLA can also be discharged to 0% without sulfation damage, provided it's not left there for more than two days.

They also don't discuss how lead-acid only keeps around 40-60% of the power that goes in, either.

A 12v 100Ah battery can provide only around 600watt-hours of useable power for every 1200 watt-hours in.  Assuming optimal conditions.
soggymaster
soggymaster
4 years, 10 months ago
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Nero above me mentioned the biggest issue I've spotted with your setup, and that's mixing old and new lead acid batteries.  One thing I'd recommend is to acquire a load tester.  This is something you can grab at an auto parts store, and will be useful for not just your solar storage, but also your car's battery.  I've found one that's $30 that'll test for bad cells, internal resistance, sulfidation, capacity, and resting voltage.  How well, I can't be certain, but it'll at least give you direction on whether the battery may just need water (always use distilled), need to be boiled (if it's sulfaded), or if it's actually bad (bad cell or internal short).
arlasser
arlasser
4 years, 10 months ago
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i have to say that probably you have at least 1 battery too old and even if you try them and you see 12V.if you apply a load at every battery and test how much time remain at the voltage, if the tension of a battery tested dropped rapidly it means you have to change that battery.
those battery that are hot are very likely almost at end of their life.
i as electrictian that work even with unit power supply (ups are those things that keeps your pc on even when there is power outage) i konw that for working at best batteries has to have a room with temperature near 20-25 °C (approx 68-77 °F), 68°F is already high and compromise batteries faster.
another thing is better when you change batteries (unless there is a battery broken too fast, it means less than 1 year that sometimes can happen) is you change all batteries not just a part because if a battery broke, happen you have a current that instead of charge all 36 batteries charge for example 30 batteries. that current will broke the other in the same series raising the current for charging the other batteries so even those new batterie will broke because for example your batteries have a current of 1,5A with borken batteries current can become 2,8A, and a battery with so much current will overheats and swells.
then another thing is guaranteed battery life usually go from the common 2-3 years then those guaranteed 5 years then other 10 or 13 based of which brand of batteries you buy.

i hope to be enough clear even if english is not my first lenguage and i'm sure there can be errors and if i'm not clear please or want some more insights tell me.

so first thing you have to do is test 1 battery at a time using a load an measure with a voltmeter if the voltage drop faster after (let's say 15-20 min) it means that battery has to by replaced
arlasser
arlasser
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
why you say you have a parallel of 18 couple whene there are 20?
and please reply if it was useful even just to say you have read it.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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dammit, i drew too many! x.x but its for sure 18, since the irl pictures show 18 per row =v
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Problem 1:
Those are marine *starter* batteries.  These are meant for providing high-amperage, but they drain rapidly.  THEY ARE NOT INTENDED TO RUN DEVICES AND ARE NOT SUITABLE FOR SOLAR POWER.  You absolutely need proper deep-cycle, non-starter batteries.
After 3 years, starter batteries will have lost 20-40% of their capacity, and only have around 50% available to begin with, and if you discharge below 50% they sulfate and take immediate damage.
Proper deep-cycle batteries last 5-7 years, while marine and hybrid batteries last 3-5 and starter batteries last 1-3.  You can expect top lost 20-40% capacity per year with starters, 15-25% with marine, and 5-15% with deep-cycle.

Your batteries are only rated for up to 450wh of storage over 24 hours, that's only 18.75 watts of useable, accessible power for every 100 amps you have.
https://www.amazon.com/gp/product/B01KN6QUW2/ref=as_li_...
These are the correct type of batteries.  These are rated for up 800wh of storage over 24 hours (@33 watts), almost twice as much storage available, lower resistant, higher efficiency, and twice the life expectancy.
Batteries over 3 years are likely in need to replacement.

So, assuming half your batteries are at their half-life, your 43,200 watt-hours is actually 17,280 after lead-acid charge efficiency losses (60%) and another 20% overall loss from age leaves you 13,824 watt-hours of useable power.  Less if they've sulfated and been damaged due to getting below 50% charge.
We're not done yet.

Problem 2:
You aren't calculating for loss.  You MUST keep in mind that a solar array only gives 100% output for a couple hours a day.  So a 1kw array doesn't put out 1kw for 8 hours a day-  only 1 to 4 hours.  Roughly every 1kw of power will make around 5 to 10 kwh of energy from the panel.
Second is the microinverter or MPPT Charger Controller losses:  Usually between 5% (for grid-tie) and 10%-40% depending on how far the panel and battery voltage is far apart.  Ideal is roughly 120v-144v input PV and 48v batteries.  For 24v, ideal is 60-72v.  Of course you need an MPPT charge controller and inverter that can handle these:  12 and 24v systems are far, far less efficient than 48v. .  So in other words, at 24v, you will lose around 10% from MPPT to Battery.  If the input voltage from the array is higher then the efficiency can be less, but assuming it's 24v panel and 24v battery, you're looking at around 40% loss.  Even 48vPV to 24vBat would be better, ~15% loss.  60v to 24v is <8% loss.
So, based on that, you're down to only 4,976wh of useable power.  Enough for a 210 watt device for 24 hours.

Your system is approximately 11.5% efficient.

That's your problem.

Third:
Also, that inverter from EDECOA is known garbage.  Look at the reviews;  Overwhelmingly negative.
It's outright unuseable.

Fourth:
These MPPT charge controllers are known junk too.  They're not balanced so you aren't supposed to pair them.
Each must be on a completely seperate PV array, battery array, and inverter.  If they share an input or output, it will cause balance issues and start causing them to cycle-crash.  The system cannot and will not use them evenly, so inevitably one will be getting overloaded while the others aren't even being used.  This is also a potential fire hazard.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Oh also, you need at least a 1-guage wire between the PV (less if it's >60v) and charge controllers, 2-guage for inverter to battery array, and at least 67mm (2/0) solid-copper conductor between the the MPPTs and battery due to their high amperage, low wattage output.  If you maxed all 240A you'd need 127mm (5/0) solid-copper.
This is why noone uses low-voltage high-amperage PV.  It's pure awful across the board and twice as expensive.
Undersized wire will also contribute to losses, crashing, and heat buildup-  It may also be a fire hazard.


Also checked and verified.  EPEVER and EDECOA offer no standard warranties for their stuff.
arlasser
arlasser
4 years, 10 months ago
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can i ask what is your work?
axlegear
axlegear
4 years, 10 months ago
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I work with electronics engineering, solar energy, battery arrays, and the like.  Formerly I was a computer technician.  :3
arlasser
arlasser
4 years, 10 months ago
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now i understand why you say all that, plus you are really specific only one that work in this field can knows all that and even if you were a tecnicians for maintaing UPS
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
I learned by fire, just like Kitsune here.  His project is going poorly but he's going to learn a FORTUNE in knowledge!

I started small by building tiny 5-volt USB systems to run a fan to cool my pet rabbit off during summer.  XD  It worked so well I expanded it to charge my phones, USB devices, game consoles, etc.
 Then I expanded to 12v, and battery backup systems, inverters, off-grid and grid-tie.
My next stage is hybrid grid-tie and BESS.

My specialty that I am 100% confident in is energy-storage and harvesting using Supercapacitor, Ultracapacitors, and Hybrid Capacitor systems.  I have some engineering sample Graphene-Silicon-Lattice/Composite batteries that are fucking incredible, but a long way from mass-production.  They're 33 and 45 true watt-hours respectively and can charge from zero to full in 15-20 minutes.  They can discharge at up to 45 watts, and at the same time charge at up to 20.  Without a load, it can charge at 45 watts.  It's nominal internal voltage is 45v per cell (no shit) and their efficiency minus controller boards is 97%.  Compare to expensive LiMnCo Lithium at 70-85%.  Best of all, they function from 3.3v to 45v, so unlike a battery and more like a capacitor, you can use over 90% of the power, as long as you have a very smart board.  They use MOSFETs but I am going to try and make a GaNFET board which should acheive >98% efficiency.  Lastly, they have an average cycle life of >100,000, vs. 300-1000 for the best and newest 4t-gen lithium, 30-100 for first-gen.  I'm at ~900 cycles and the capacity is actually still above the rating:  The 33wh provides 41wh and the 45wh provides 66wh, each with a 2.5-watt fan load.  Absolutely no complaints from me!  I can fully recharge my smartphone twice with 5% left over.
The company is making graphene-anode lithium batteries on their website for sale:
https://elecjet.com/
These are MUCH higher capacity, and they DO charge very fast, but they're not the new tech yet.
arlasser
arlasser
4 years, 10 months ago
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sorry for my bad english and my terminology was "not correct" here we have 220V 50Hz, so you know that can be differences but laws of elecrticity are always the same
axlegear
axlegear
4 years, 10 months ago
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Correct.  Although I will say that there are a lot of headaches for us in the US with the way we split phases.  Good for lights and electronics, fucking terrible for motors and big appliances.
I like 240v 2-phase and 3-phase, but that's because I like big machines with big energy needs.  XD
I suck at A/C, my specialty is DC.  It makes more sense, and requires less* (not none) knowledge of complex systems and electromagnetism.  But you have to get into both to complete your education.

I'm about 60% confident in DC electronics, 80% in energy harvesting, 40% in A/C grid works, if I had to rate myself for how I would compare to my co-workers and peers with college degrees.  I need more experience with residential networks.

But with DC, I can power everything that would normally use a DC power brick using a single mega-hub and solar.  XD  It's just VERY hard to scale this past 45 watt devices and especially A/C.
arlasser
arlasser
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
wow i can't belive you suggested batteries with gel instead of the classic.
those type of batteries are still new and offer an high amperage instead of the traditionals.
i just review the photo and i have to concord with you about the risk of fire with the section of wires.
i didn't want to talk about the device used for conversion of enegy so i said nothing but i have to say you were exhaustive
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Thank you!

I started doing this DIY with early mono and poly crystal, amorphous and CIGS panels.  Then started building my own battery packs from 18650 cells and expanded.
It's still pretty small, but people get a kick out of seeing my run a small desktop and soldering iron to add stuff onto the same system that's running it.  XD  Ouroboros power!

The power world is so full of complications, difficulties, bad info, and outright lies.  Few manufacturers are entirely forthright and honest, and everyone wants to sell their product-  not so concerned on how good it works.
Solar is ripe for scams, because working systems are so desireable.

So I try very hard to give people ALL the info, and only good info!  Experience is also a great teacher.
arlasser
arlasser
4 years, 10 months ago
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in your country there is a law that say when there is power outage the inverter has to shut down for safety? so firefighters don't risk their life?
think how much can be risky using an UPS at home and when there is a fire at home firefighters go in thinking there is no power and then they receive a shock because the UPS was still on.

the problem with what he want do, is this solution is really pricy and every 10 years has to pay something like 10000 € of batteies and you don't have so much load when you really need (the night)
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Correct, this is called 'Islanding'.  If a grid-tie system detects the grid goes down, it stops feeding power to line workers don't risk electrocution.

The battery cost can be very extreme, yes.  This is why I can't reccomend using any kind of normal lead-acid battery.  Even deep-cycle true gel cells are kinda costly-  silicon-SLA are best suited, but hard to find still.

Lithium is most cost effective but there are dangers in all except LiFe, which can last for decades without trouble.  However they're expensive and hard to find on the open market.

The biggest thing is to use the highest voltage possible for your batteries:  48v is the highest you can go in the US until you have to adhere to complex NEC safety codes.  Same applies if you do ANY kind of grid-tie, even passive and hybrid grid-tie.
If you can meet specs, however, the best battery systems are 144v arrays, currently.  Ideally using LiFePO4, cold-flow, or silicon-SLA gels, but only cold-flow gets those voltages without being a big expensive array with many parts.  Cold-flow is extremely expensive and very, very hard to find.  Few systems support them, either.  Unsuitable for home grids.
arlasser
arlasser
4 years, 10 months ago
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there are so many ways you can do that now we use these type of batteries the only producer is "optima" https://www.amazon.it/Batteria-Optima-YTS-5-5-Wrangler-... i think these batterie are AGM and good for "long race"
arlasser
arlasser
4 years, 10 months ago
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can you provide link for battery silicon-sla?
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
"Question:What is the maximum charging amperage?
Answer:SiO2 batteries are .25c, so the 100Ah 12V battery can be charged at .25A, 12V."

That's 30 watts in/out max total
More is possible but will not get the RC or AH/R
axlegear
axlegear
4 years, 10 months ago
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Optima is a VERY good brand
They have a high DOA rate but every cell i've ever seen tested that worked, worked well and long.

Usually I never ignore ratings, but I respect Optima.  They're trying hard, and that takes work.

Silicon-AGMs are very new and expensive and it's hard to find them on the open market realiably.  They're common on Ali Express but I never ever use them because of scams.
Sorry, I don't have a good source now, but you can call local Solar companies to see if they have access and buy them individually or wholesale.
They are very very very very very expensive this way.  But if you really need the best lead-acid, this is it.  They are longer-lasting than most lithium (except LiFe) but still only have 60% efficiency and capacity.  Unlike normal though, they can go below 40% charge okay, for a couple days.  But 72h is the most:  48h at <20% and 24h at <5%.  They DO sulfate, but only after a while and very slowly.  They are new so none have lasted past 12 years, but 12 years is the record and most make it 5-8 under HEAVY load.
https://www.amazon.com/recyclable-lifespan-discharge-te...
This is the one i've seen tested a great!
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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then its so fucking strange that everyone recommends this batteries for solar and say it works great in their systems~ =l wish we could be doing it wrong and getting those good outcomes.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Who is 'they' and what are they using?  With a system like this, the expectation for efficiency is far too high to be realistic.  And like a lot have said as well, these batteries aren't appropriate and old batteries should never be mixed.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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there are reviews on these batteries, on the site i linked for the battery, stating they worked on their solar setups, and they work.

and why exactly arent these batteries useable??? because they produce the cranking amps AND the Amp Hours that EVERYTHING ON PAPER says we need to make it work =l

and we've tried the new batteries vs the old batteries, AND THE ACT EXACTLY THE SAME.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Because the cold cranking amperage is just that-  the amperage provided, cold, when cranking:  A sub-minute draw.
Starter batteries are designed to provide high initial amperage.  They are not designed to withstand constant draws due to the way the electrolyte motility works.
You need the Reserve Capacity Amperage, and the Nominal Amperage Capacity.  For starters, this is usually 0.5 to 1.2 amps (6-15 watts) and for marines this is usually 2-3 amps (24-36 watts), but deep cycles usually handle 5 to 10 amps (60-120 watts) over a 20-hour period.

Batteries like this are suitable for short-term backups, such as UPS devices or powering emergency lights.  They have to be scaled to ridiculous levels to provide capacity, whereas gel cells, lithium, and silicon-sla are designed for constant, regular draws.

Secondly, you're using the nominal amperage, not the working amperage.  Lead-acid batteries use about twice the amperage internally to produce the same externally:
A 1 amp draw pulls 2 amps from the cells.  This is because of the plate architecture efficiencies:  STI/starter batteries have ~40 efficiency and charge availability, meaning a 100Ah STI will only have 40Ah of useable power, MINUS the inverter losses.
Hybrid and marine cells are ~50% efficienct.
DC-Gel cells are ~60-70% and silicon-SLA gel cells are ~70-75%.

Lithium varies from 60 to 93%, with some better new tech soon to come.

http://web.mit.edu/evt/summary_battery_specifications.pdf

This link explains all the different characteristics of batteries.

https://www.pololu.com/blog/2/understanding-battery-cap...

This goes into more detail.


STI batteries can only provide their Ah rating at their optimal discharge rate, NOT the cold cranking amperage.  The amperage drops off rapidly after the first few seconds.
Always look at the rated draw capacity for 24-hour periods or longer with solar!  72 is reccomended!
axlegear
axlegear
4 years, 10 months ago
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This quote specifically:

"4. CCA, CA, AH and RC. These are the standards that most battery companies use to rate the output and capacity of a battery.

Cold cranking amps (CCA) is a measurement of the number of amps a battery can deliver at 0°F for 30 seconds and not drop below 7.2 volts. So a high CCA battery rating is especially important in starting battery applications, and in cold weather.This measurement is not particularly important in deep cycle batteries, though it is the most commonly "known" battery measurement.

CA is cranking amps measured at 32°F. This rating is also called marine cranking amps (MCA). Hot cranking amps (HCA) is seldom used any longer but is measured at 80°F.

Reserve Capacity (RC) is a very important battery rating. This is the number of minutes a fully charged battery at 80°F will discharge 25 amps until the battery drops below 10.5 volts.

An amp hour (AH) is a rating usually found on deep cycle batteries. The standard rating is an amp rating taken for 20 hours. What this means for a 100 AH rated battery is this: Draw from the battery for 20 hours, and it will provide a total of 100 amp hours. That translates to about 5 amps an hour. (5 x 20 = 100). However, it's very important to know that the total time of discharge and load applied is not a linear relationship. As your load increases, your realized capacity decreases. This means if you discharged that same 100 AH battery by a 100 amp load, it will not give you one hour of runtime. On the contrary, the perceived capacity of the battery will be that of 64 amp hours."
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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but in total it says all 36 batteries are taking only 31 amps~ from them ALL.... =l
axlegear
axlegear
4 years, 10 months ago
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You're still not allocating for losses and chemical efficiencies. Those numbers are variables, not solids.  You can sabotage them.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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fine, lets assume that 50% magically just disappears, we should have 21,600 watts... IT DOESNT EVEN LAST THAT LONG =l
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
You're still ignoring all the other info.

Remember early I roughballed the total efficiency to 11.5%.

So that's more like 4.3kwh.

Assuming 100% efficiency of your inverter and charge controllers, all 36 batteries would only be rated for 430-600 watts at 20 hours:  only 8 hours at 1.2 kw
Double at 24v


To get 50% power out (100% efficiency), you'd need to draw at no more than 0.1 amps per battery max:  3.6 amps@24v = 86.4 watts over 241 hours
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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... but we're getting the same results even after DOUBLING the batteries =l even if your 11.5% is real/correct, adding batteries should of done SOMETHING
axlegear
axlegear
4 years, 10 months ago
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Now factor for the 70% inverter efficiency:

That means at this rate, you'd still only get 16.1kwh out maximum
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
that feels like a complete dodge of what i just said

regardless, you say we should get 16.1kw? GREAT! we only get about 7kw AS IS IF LUCKY, WHAT THE FUCK IS HAPPENING
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Please calm down.  I and others are explaining what's happening.
Again, that's 16kwh at 100% efficiency.
You do not have that.
You do not have half that.
You do not have 1/4 that.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
no? its supposed to be 43200watts, and everyone says those calculations are correct, BUT even with losing 75% magically, we're not getting even that! XD

ANNNND adding more batteries, no matter if its 50% more, or 300% more, does NOT increase capacity, EVEN if its fully charged. that makes no damn sense XD
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
It's more like 88.5% loss.

And your inverter is bad.  Very bad.
Get a better inverter and you'll get more out.  Up to 90% more, realistically.
Get a single, proper battery array, and charge controller.  That'll give another ~90% and ~95% boost respectively.
Get thicker wires.  That will prevent voltage sag and low-amperage.

The room for improvement is immense.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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then we'd actually be better off uses these batteries as a weight system to pull gears and generating power i guess. i wonder why people uses these as batteries at all.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
They're for electric fences, security lights, UPS backups, etc.
Stuff that is either VERY VERY tiny, or only runs for a few minutes at a time.
Boats, for example.  Hence why they're called 'marine cells'
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
then why have i see people running 4ACs with these?! :l for 8 hours at a time
axlegear
axlegear
4 years, 10 months ago
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kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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-2 gauge isnt enough?! upgrading the wires to more would be about 2000$ XD
and i dont see why the inverter is bad, 700 watts go in, 700watts go out. there isnt a fuckin trickle of power out of it, via some 88% loss XD
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
I'm going to have to say that you're incorrect.  No inverter could ever give 700 in 700 out.  A wire can't technically do that.
Even 800 in 600 out would be game-changing world headlines.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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well by all monitoring devices we have there is FOR ABSOLUTE SURE no 88% loss happening. checking it from 4 different points in the system, and via multimeters, no massive drop is happening like that.
axlegear
axlegear
4 years, 10 months ago
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Think about it logically.  If there's no loss occuring, then why is the array running down so quickly?

I assume you've made sure there aren't any shorts, and I assume you're using accurate ways to test your draw?

What is your inverter's idle draw?
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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idle draw? with nothing being powered? its i think about 24 watts? with the basics of what we want on, its 700, and with all the things we really want on, its 1500-2000 watts =l
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Basically then your target draw as everything is right now should be 276-576 watts over 20-hours.
Double that for 8 hours.
Double again for 3 hours.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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well thats stupid, since we can do 1500 watts over 11 hours with half the batteries we do now!

so then what we could do is some automatic battery bank switch so that we use 1, then switch to the other, then when the sun is up, connect both, and then charge them up. some kinda complicated timing system with automatic switches.

because just connecting batteries doesnt work apparently, when it should according to all scaling principles.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
And yes.  High amperage means huge fucking cables!

This is why 12v is never for this kind of system.  48v minimum just to run a single 1.5kw A/C, and even that requires a 6kw array with a 48v 330Ah LiFePO4 pack.

Anyone who said they were running a 1-ton HVAC or more than one on this is a vicious liar.  That is mathematically impossible.
A 1-ton unit draws 2.5kw with a 6 to 8 kw peak.
A 1.5-ton unit (US most common) is 4kw with a 10kw peak.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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well that cant be correct, since on our 24 volt system, we can run 2 ACs totally about 1.5KW about till dawn =/ so i guess we're doing the impossible in some way here.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Technically, yes.  Because your batteries aren't balanced or the right chemistry.  XD  That's why you have to use so damn many!

I'm not trying to be rude, there is just a lot of things that you were clearly not told about this project.  It's built to overcompensate for loss rather than being efficient to start.  This is a runaway train where things just get worse and worse over time, too.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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im just mystified that doubling the batteries hasn't not resulted in any increase of capacity. when every source on the internet says it will.
axlegear
axlegear
4 years, 10 months ago
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It probably did, but there's others factors negating the difference from being noticeable.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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so we're doubled the power we store, but it just magically disappears. we make no additional heat, and none of the monitoring devices are saying we've lost more power anywhere. that seems highly highly unlikely.
axlegear
axlegear
4 years, 10 months ago
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Nothing magically disappears.  It's going somewhere!
If it's not a short, then it's inefficiency.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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well its more likely a short than inefficiency at this point, because nothing is indicating we're losing massive amounts of power to inefficiency. whats being powered is whats being drained =/

OR its some kinda bad wiring pattern.
Corona688
Corona688
4 years, 9 months ago
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Edited 4 years, 9 months ago by Owner
"We make no additional heat"

Think about that a moment.  How would you make additional heat?  All waste becomes heat.
kitsuneyoukai
kitsuneyoukai
4 years, 9 months ago
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there is no heat after they are fully charged though.
XaldonAjide
XaldonAjide
4 years, 10 months ago
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Just a query, are your batteries hooked up to the grid in any way? could be Deliberate siphoning by the power companies. atleast that's what they are doing down here in midflorida. also good to see so many people in florida.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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nope we have it totally separated from the house power :o
wollypegger
wollypegger
4 years, 10 months ago
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You really should not mix old batteries with new batteries without an isolation system in place.

One bad cell in an old battery will drain the array.

Try disconnecting batteries one at a time. or a set at a time depending on the arrangement of the array, and see if the disconnection improves longevity.
axlegear
axlegear
4 years, 10 months ago
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Agreed.  I build my own battery packs from 18650 cells, so I am very used to the tedium of testing every single individual cell, attaching fuses and a balancer circuit, then testing every single pack.
It pays off.  One missed connection and blammo!  Day ruined.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Here's a loss tree:

Panels to Charge Controllers:
At 6-guage wire, assume 3% loss
Then apply 10% loss per Epever charge controller
Add additional 10% for each PV or battery array.  IE, 2 PV arrays and 2 battery arrays = 20% extra
At /00 guage wire, assume 3% loss
This completes the 'input' calculations:

Penalize 1% per battery per 100Ah (self-drain) at 24v.  Double at 12v.  Halve at 48v.  (Lower voltage cells self-discharge faster)
Penalize 1% per battery if using a balancer, else it's closer to 6%
Then penalize 30% for lithium, 40% for gel cells, 50% for marine and hybrid cells, 60% for STI/starter batteries
Penalize 30% for EPEVER inverter at 24v or 40% at 12v

Neither the charge controller nor inverter offer their efficiencies specced while under real loads.  This is why they're so poorly reviewed.  You have to hit the maximum input voltage at only 0.1A grid draw (60w max) to reach >90% efficiencies on the inverter.

You see, there isn't just one problem.  It's a whole boat load of them.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
link
we're for absolute putting in 5-6kw, there is no 'loss' happening. the monitoring device clearly says its that amount of power going at the point of entry to the batteries, NOT the charge controllers saying that, though it lines up with their indicated amounts too.

we'll be generous and say 5kw is FOR SURE going in... and then its in the batteries, right?...

and then thats indicated via several monitors is that we're taking 700-1500, and according to all the math, and what all the displays are saying... we should be able to last 24 hours or more! :l

on a possible unrelated note, what pattern of 24v battery would you do? =T we just spent the day rewiring it into a new pattern, and also adding a kill switch :V which works nicely.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
Almost

Once the 5kw hits the batteries, they only keep 50% of it.  That's just how electrolytes work.  This doesn't 'come out', it's wasted as heat and other waste energies.

So, that's 2.5kW that gets charged in.

Now that said, the batteries are only rated for a 285 minute RC current.  So realistically you should be able to pull 300 watts for 24 hours, 600 watts for 10 hours, and 1200 watts for 4 hours.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
link
well we can absolutely draw more power than that as is, we've done 3000 watts longer than that. so again, we're doing something impossible here, just wish it'd do more impossible better i guess.
axlegear
axlegear
4 years, 10 months ago
link
Edited 4 years, 10 months ago by Owner
What do you mean 'pattern'?  There's only balanced or unbalanced.  XD

A 24v array should be a single 24v array with paired parralel.  Nothing should be a different size.  They should be 2x2 and then balanced or isolated.  If you're just sticking it 2x18 then you're going to be doing terrible things to their balance, and most likely one or several are overvolted or undervolted and sabotaging the array.  This is why balancing is necessary, else you're stuck 2x2 for 24v or 4x4 for 48v.  Technically 1x4 at 12v is fine, but if you go much further then balance gets fucky again.

It's about much more than just quantity.  If one of the cells in a 2x2 is, say, 25Ah due to age, and the others 100ah it's going to hurt them all by about 25%:  A ludicrous 75Ah loss just because one cell is weak.  This doesn't happen if you use a balancer.

A balancer is the only safe way to have an non-synchronous array.  Going without and using lithium is very likely to cause an extremely severe fire.  Lead-acid much less likely, but you will ruin them and fast.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
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axlegear
axlegear
4 years, 10 months ago
link
Edited 4 years, 10 months ago by Owner
That would be a 2x3 24v
2x3 isn't as safe as 2x2, but popular for cheap setups.  I'm okay with it.
2x4 is a squeegier, and I cannot reccomend 2x5 or 2x6 due to balance.

It's best to keep it square:  1x1, 2x2, 4x4, or if you have a NEC-legal pro system you can do 5x5, 6x6, all the way to 28x28 (360v peak systems).  But most people don't have access to cheap equipment for those, so 48x 4x4 is best.
If you need more power, it's better to get a second inverter and break the battery arrays and loads.

For example, I run a 2x2 12v (100Ah true gel batteries) to power my printer (~30-40 watts active, 220w peak) on a 300w sustained 600w peak pure sine inverter.
Then I have a 25ah marine cell 12v by itself connected to a 300v inverter.  This does nothing usually, but if power is out I use this for weather radio and phones, TV, etc. and also my soldering iron, battery welder, and emulator system.  The sloldering iron is 150w and the rest is all under 15w.  It lasts for around 5-6 hours to game or radio on, and about half an hour for the soldering iron.  I can't usually run anything else with the soldering iron on.  ~175w and the inverter cuts out.  But it SAYS ON THE BOX that it's 300w!  Doesn't it?
...300w peak.   150w sustained.  Damn those packaging!



KEEP IN MIND
This only applies to lead-acid

Lithium is waaaaay tougher and stronger and you can run entire A/Cs off a single battery just fine if it's the right size.  No 2x2 needed.

LiMnCo Lithium batteries, for example, can handle a 30C rate.  That's 1440 watts on a single 48v 100Ah battery.  CONSTANT.  Lead-acid can't do constant very good, period.
NOW you see why lithium is expensive but popular.  You'd need 24 12v lead-acids just to equal the amperage.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
link
Edited 4 years, 10 months ago by Owner
https://cdn.discordapp.com/attachments/5971743683421143... is the pattern we're trying out right now. seems to be holding fine so far. (i didnt put the input/output from contollers :v) but this is the general idea

https://cdn.discordapp.com/attachments/5971743683421143...
this is what we tried yesterday.

but this this set up and the materials at hand, what pattern would you do? there is apparently hundreds of way to wire it...
axlegear
axlegear
4 years, 10 months ago
link
Edited 4 years, 10 months ago by Owner
For maximum efficiency/most watt-hours, you'd break everything:
1 array, 1 charge controller, 2x2 batteries, 1 inverter.

Anything else will offer more starting amperage, but lower efficiency (thus less wh)

Prefer voltage over amperage:  24v is better than 12v by a LOT.

2x2 24v should be fine for a 250w load for 6+ hours or a 30w load for 48+.
2x4 24v should be fine for a 450w load
2x6 24v should be fine for 600w/6h
I can't reccomend past that because of balance.

Basically, the less you draw, the longer it will last closer to it's 'rated' amp hours.  It is NOT linear!
Also keep in mind that as the voltage changes, so does the battery behavior.
As the voltage drops, the amperage of the load increases even while the battery's amperage drops.  IT'S NOT ABOUT WATTAGE ALONE!

This assumes 100% inverter efficiency.  Again, no such animal:  Average efficiency at 24v to 120vAC is only 70%.  12v to 120vAC is ~60%.  However 48v to 120vAC is ~85%+.  72v to 120v can hit 98%, but that's rough to build and those inverters cost a fortune.
kitsuneyoukai
kitsuneyoukai
4 years, 10 months ago
link
so you cant give a diagram of how you'd wire these batteries? just the batteries alone.
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
I've been thinking long and hard on this and I just can't answer easily or quickly, but I can give you a correct answer if I get more info

What methods do you have to test each individual battery?  Namely I need to test voltage, amperage, amperage draw over time, initial pulse amperage, and parasitic drain.  I know it's asking a lot, so I will try to help:

First, you should make sure the battery is reading at least 9v, preferably 10.4v or more.  Below 10.4 most lead-acid batteries start taking damage, regardless of type or tech or age.  So if anything is reading below 9v, it's basically dead.  Remove it.
If it's below 10.4 after being charged for a few hours with NO load, then it's also bad.  Ditch it.

Once this is done, we can move to the next stage:
Charge the batteries to their nominal float voltage.  Once they're disconnected they should be at this voltage.  I THINK it's 13.8v for these but I can't find the documentation to be sure, 13.8 is just common for marine deep-cycles.
Let it sit for an hour and check it again.  If it's below 12.8v, it's bad and parasitic.  Ditch it.
Wait another 23 hours- 24 hours total, and it should be around 12.6v.  If it's below 12.4 it's bad, but not useless-  keep it on a different grid from the good batteries.
PLEASE PLEASE note these numbers change by around 0.1 to 0.6v depending on the battery design.  NOT TYPE OR TECH!  CHECK the specs documentation!

Stage 3:
Now you need to put a load on the battery.  PLEASE use a 12v DC load, do NOT use an inverter for this!  Do not exceed 20 watts.  Charge the battery back to floating voltage, then connect the load and measure how long it's valid.  Using a light for this kinda sucks because they can run at bad voltages, so I reccomend a testing device or something that needs steady constant power and has no motors.  I literally plug my smartphone in and make it loop a video or music.  That's usually ~2 watts.
The lower your draw, the more watt-hours/amp-hours you will read.  So unlike me, you want to test for 15-20, maybe 25 watts if you have high expectations like HVAC or A/C.
Make note of the total hours it runs before dropping to 11v.  This is your REAL amp-hours/watt-hours.  Record this for EVERY battery cell.

Once I have this info, I can better advise you on the most efficient way to configure the batteries.
I'm sorry it's so much work, but it's necessary to see what each battery's performance is so they are balanced manually.  The other option is a battery balancing circuit, which is expensive and hard to wire up.  This IS the best option, but I understand you don't want to spend more and you are already SO CLOSE to everything working fine!

With this, we can get the batteries working as good as possible.  If that doesn't fix it, we can move on.  But let's see if we can fix this without spending more!
arlasser
arlasser
4 years, 10 months ago
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you know these are the scheme you use in UPS to have more efficency and more safety
TheDeinonychus
TheDeinonychus
4 years, 10 months ago
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The unfortunate fact is that solar panels are not a very efficient means of power generation. Even with the most efficient panels you can get, they are very sensitive to even the smallest changes when it comes to their power output. A slightly overcast day, dust on the panels, even ambient temperature can have a huge impact on how much power they generate.

On top of that, despite what is 'common knowledge', hot temperatures actually drain batteries faster than cold temperatures. The reason cars have trouble cranking in cold weather is because the low temperatures slows down the chemical reactions in a battery. The energy is still stored inside, but it's harder to get it out when you need it. On the flip side, hot temperatures actually speed up the reactions, causing batteries to bleed of their charge a lot faster than they otherwise would.

Unless you have a very large array of panels, or some other way to supplement your energy generation at times when the panels are not getting full, unobstructed sunlight (such as a windmill generator, or a water wheel), you're going to have trouble generating enough power for the entire day plus saving up to last the night.
axlegear
axlegear
4 years, 10 months ago
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Nothing here is false, but I want to note that heat doesn't just fuck up batteries, it also makes wires' resistance worse and can make them act smaller (roughly every 30F from 70 is like a guage down!) and solar panels can lose as much as 30% efficiency when they overheat.

There's SO FUCKING MUCH to take into consideration...
Solar is 100% possible.  But not without some real research and education and a LOT of patience and dedication.
And an appetite for mistake.
TheDeinonychus
TheDeinonychus
4 years, 10 months ago
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Yes, as materials (particularly metals) heat up, their electrical resistance rises. That's actually the main reason overheating is bad for computers. Not only can the heat damage some components, it saps power from the system and slows it down. Compounded by the fact that, as the resistance rises, the current that does flow generates more heat, and thus raises the resistance further.

While the temperature might not be wholly to blame for Kit's issues, it's likely amplifying them.

Personally, I've always viewed solar and wind power as being supplementary, rather than a primary power source. With as power hungry as homes can be these days, there's no way solar and wind generation can keep up on a household scale, at least not with the technology we currently have in the field. It's unfortunate all those subsidies went towards shutting down powerplants and paying for solar and wind farms that barely last 10 years instead of towards research to actually make those energy sources more viable.  
axlegear
axlegear
4 years, 10 months ago
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Edited 4 years, 10 months ago by Owner
My first love was computers and their hardware.  This is what got me intro electromagnetics, DC electronics, etc.

Thermodynamics and metallurgy, and now crystallurgy, are the finest current exploits of technology realized, IMHO.  Everything else is still theoretical and under valuable exploration!

I, too, see solar as a supplement.  Right now it's between 0.7 and 2.7% of my bill discounted, which is tiny.  But it paid for itself in 6 years or less.
I just can't run an A/C.  XD

$50 250-watt 30v panels:  

https://store.santansolar.com/product/santan-solar-t-se...
TheDeinonychus
TheDeinonychus
4 years, 10 months ago
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When I first moved into my dad's old trailer, I thought about setting up some solar panels to offset part of my electric bill, but unfortunately the location meant it wouldn't be worth the effort (in a valley with lost of tree cover). Hydro would have been a much better option, but the creek on the back of his property is too small XD
8manx2
8manx2
4 years, 10 months ago
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This reminds me of a strange phenomenon where a boat would loose power inexplicitly in the middle of the Bermuda triangle. Every time they would send the boat out it would die. Finally someone looked at the engine to find out why. It turned out that it was missed wired, so instead of the engine feeding power to the batteries it leached it instead. Also you might want to make sure your neighbors aren't stealing it  
Nech
Nech
4 years, 10 months ago
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you have one or more parasitic batteries.

one or more were improperly maintained or over drawn and your electrode plates have begun to or have completely disintegrated.

when this happens to batteries in parallel the remaining good batteries will try to self balance between the attached batteries in parallel and "charge" the bad battery.
primary symptom of this is the bad battery will accept a charge but its capacity is so reduced that once a significant load hits it, it rapidly drops in voltage.
this then causes the other batteries to start to try and balance the voltage between the higher SoC batteries and the drained bad battery, which then serves to compound your drain between the actual system drain and the drain caused by the bad battery.

as far as patterns for efficiency it would be far easier to speak than type it out, to many different options.

PM me if you want and i can jump on a google meet call with you.

suffice to say you can do a number of things to increase your efficiency, your current design is not the most efficient and is actually causing some lose due to how it's all set up.
Nech
Nech
4 years, 10 months ago
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for reference we also use a solar system on the family farm for several things and i also manage a datacenter as part of my job, including engineering the backup power system for the core infrastructure.
axlegear
axlegear
4 years, 10 months ago
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Good advice, also, if you wanna talk with me please do.  I am very obsessed with the field and would love any advice, news, etc. you care to share!
Nech
Nech
4 years, 10 months ago
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more so i know about it because i needed to learn it to use it or fix it, tends to be how i end up learning most things; either i need to fix something or i need to know how to build/do something in order to get something done or not pay a stupid amount of money to some schmuck trying to markup his stuff 400+% to make a buck off everyone else's back.

pretty much how i learned most things outside of IT (what i do learn for fun/interest) from welding to EE to forging to RFCOMMs design and it goes on and on.
Tuoqui
Tuoqui
4 years, 9 months ago
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I say check the math again... I'm not sure but I suspect you're using the maximum output potential for your solar panels/array. If it's in a fixed location on a roof then the panels will not be delivering the maximum output very often usually only at a certain point of the day. If you are lucky enough that your solar array is one of those sun tracking ones though you'll probably get a result closer to that number though you'll still have losses just not as much as it can keep the panels at an optimal angle to the sun for most of the day.

Are those 100AH for each battery or is it 100AH total of batteries? If the later you can expect if you used a load of about 1.5KW that it would discharge to empty in about 17 hours (70% of a day) because 100AH of 24V batteries can deliver 24 watts for 100 hours... Every doubling of watts needed halfs the length of time the battery can supply that amount of current.
Corona688
Corona688
4 years, 9 months ago
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Have you tested all your batteries?  If any of them is shorting inside that can drain your power real fast.
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