crazy battery issues

[douglasjett]

Hi All. My first post, new at this.. I'm down in Baja and it's very hard to find someone to help with technical issues. I have a major problem with my battery bank.

I have a 24 volt, 2300 watt panel array feeding 10 'Data Safe" 96ah batteries and a cheap Ebay Chinese 8000 watt inverter. The issue is the batteries will not equalize. In the morning one side of the battery bank will read say 13 volts and the other side of the pair will be in the 11.5v range (dead!) I suspect I've got several bad cells in the bank but am having trouble isolating them... I have removed the batteries at full charge isolated all of them and watch for voltage drops, one dropped immediately and I replaced it. The problem persists. On top of this recently I had one battery get very hot (boiling)... I removed it for the day but it holds a charge so I put it back in the bank... Also worth mention is that I didn't wire the system. I purchased it as a pre made kit; 4 batteries in a crate with inverter and charge controller and 6 outside...

Thanks for any help

[SunEagle]

Hello douglasjett and welcome to Solar Panel Talk

To help us understand the issue we would need to know how those 10 96Ah batteries are wired, as well as what Charge controller are you using for that 2300 watt array. A 24 volt battery system would need an MPPT CC with about 100amp (2300w / 24v = 96amps) which they do not make, so tell us how your array is mounted in compass direction along with how they are wired to your CC.

My quick guess is that you have multiple parallel sets of batteries along with a very large inverter. Chances are the batteries did not get charged or are being discharged equally so you have lost one or more of them. Again this is just my guess based on the info you have provided.

[douglasjett]

I have (9) 255w panels. I installed them with 4 way splitters, 4 on one wire, 4 on another and 1 on its own. So, there are 3 positive and 3 negative wires running to the CC simply spliced at the CC.. I've never gotten more than 70 amps to the CC. I had to remove the inverter to snap the photo and I do see that a couple of those batteries have been leaking a bit.... uggg

[Mike90250]

"Data Safe" batteries sound a lot like UPS batteries, which will only last 100 or so deep cycles. Can you see what the date code is, on the batteries, I hope you were not scammed into buying 5 year old used data center batteries in a fancy crate.

[douglasjett]

There is a barcode sticker with 2 numbers on it; TLIC2511142 and 6660211313

And I think Mike is correct, they are UPS batteries

[Suprasoup]

The charge controller looks like a SolarEpic 80a PWM controller. You will only see about 70a using that charge controller. PWM controller is current in = current out.

Each of your 255w panels outputs roughly 8a. Your panels are connected in parallel to the controller so: 9 x 8a = 72 a. So in effect you turned your 2300w array into a 1700w array using that controller.

[SunEagle]

The charge controller looks like a SolarEpic 80a PWM controller. You will only see about 70a using that charge controller. PWM controller is current in = current out.

Each of your 255w panels outputs roughly 8a. Your panels are connected in parallel to the controller so: 9 x 8a = 72 a. So in effect you turned your 2300w array into a 1700w array using that controller.

If all of the panels are connected in parallel is the OP producing a high enough voltage to charge a 24volt battery bank?

If so then you are correct that CC is still robing him of about 30% of the panel wattage.

[douglasjett]

OK guys.. Thanks for all the input on my panels and CC... But, I am really interested in how to fix my battery problems.. Cheers

[Mike90250]

OK guys.. Thanks for all the input on my panels and CC... But, I am really interested in how to fix my battery problems.. Cheers

I think the fix is a new battery bank, before the old one dies completly

[Sunking]

OK guys.. Thanks for all the input on my panels and CC... But, I am really interested in how to fix my battery problems.. Cheers

Simple drive by a lake and give all your batteries to someone with a boat in need of an anchor because that is all they are good for. The determine what Amp Hour battery you need, and then buy new batteries. NEVER EVER PARALLEL your batteries or use any battery not made for Deep Cycling.

Bottom line is your batteries are toast, get rid of them and replace them.

[douglasjett]

Thanks guys, but not real helpful. Remember I purchased this setup from a company in Phoenix and wired it to his specification. So, if they are crap batteries, or if they are wired incorrectly please let me know.. At least I can confront him with it. Thanks again!

[Suprasoup]

Read this to understand why paralleling batteries is not a good idea:

http://www.smartgauge.co.uk/batt_con.html

your batteries are UPS batteries and are not appropriate for your application.

[douglasjett]

well, I've been trying to fix this issue for months. So, I have wired the batteries in series.. The results however were not good, dead batteries every morning. I'm sure that is due to bad cells, but thats why I've switched it back. Sounds like he sold me batteries he shouldn't have. I'm not happy about that.

[littleharbor]

So you series wired the batteries and were still charging with a 24 volt charging source? That would explain your dead batteries.

[Mike90250]

The batteries were never close to the proper deep cycle batteries you need. They were halfway dead in a month.
Additionally, those were sealed batteries, and should not be equalized, the seller configured the Charge Controller improperly.

Next try, use 6v 200ah golf cart batteries, 4 in series gives you 24V @ 200ah. You can parallel another 4, wired on the diagonal (per Smartgauge site link above) and get 400ah.
A 24V, 400ah system is pretty good sized, and if you need more, I'd head to 48V land.