That's about 40 amps charging current.

What is your load current?

Are your new batteries all the same model?

Are they well connected with 8 gauge wire or thicker?

Hello Jerry48,

This is just a thought, and the 'in series' batteries would be a nonsense......... But, have you thought about connecting each battery separately to the Controller, just to see what happens? It would mean having five lines rather than one, but, as long as there was enough room in the connection side of the controller it may be worth it and it would spread the load, which does not seems to be happening at the moment, at least not very efficiently.

Can you try a different controller or perhaps borrow one to see if the fault may be with the controller. I am pretty sure you know what you are doing, and this is just a suggestion, OK? No insult intended.

Dear Friend

Are all 5 batteries identical in all respect or not? If yes, then load is low, conversely power plant rating is higher for given load. Pls. confirm battery capacity & inverter rating.

You could either increase your load and if that is not possible then remove 1 panel and see the behaviour. If it is still behaving in same way then you can try removing 2 panels. Nothing will happen if batteries get deep discharged.

Thanks & regards

Ashok Toshniwal, Bangalore, India

All my battery cables are No. 2 gauge.

All batteries are identical and I bought all at the same time - 12v 115ah - hooked up in parallel for a 12v system.

I'm now trying hooking my positive from the solar panels to the lead battery positive and the negative from the solar panels to the negative of the last battery of the bank to see if I get more uniform charging. Don't know if it will make a differance since they're all cabled together so I'll have to let you know what the result is.

This house is one that I'm remodeling so since I'm not living there the only loads I have on the system at this time are lights on a timer for security and power tools.

My controller is a simple design that monitors battery voltage and activates a large relay for a dump load that will be a 12v water heater element but for now is just a disconnect.

I've monitored the battery voltage with a volt meter while the controler is in operation, and sure enough the lead battery voltage is rising higher than the rest of the batteries in the bank and triggers the dump control. But as soon as the relay disconnects, the lead battery voltage calms down to the voltage of the rest of the battery bank and now tells the control to charge again. That's what gave me the idea of moving the solar panel negative to the last battery negative. I'm also going to move the controller battey monitoring cables some where else on the battery bank other than on the lead battery.

I may just have a bum battery, but it's boiling the lead battery enough that its spitting out water from the cell caps but not from the other batteries.

Dear Jerry

Check specific gravity of each battery. If it is high, in any of the cells, then add distilled water to make it uniform.

Thanks and regards

Ashok Toshniwal, Bangalore, India

Yeah I had the same thought. Didn't make since why one battery was boiling more than the rest. All connections look clean, new batteries, new cables, just one battery is acting strangely. Not over heating or swelling just getting a higher voltage than the others and boiling out, crazy,

thanks

Jerry,

Somethings fishy here. There's no way you should have ANY significant difference in charge/discharge voltage on a bank of batteries connected in parallel with #2 gauge wire!!

UPDATE: just went back to re-read some of the comments, and I see that BLINK has covered most of what I would have said, beat me to it! As he said, I'm going to guess a bad connection somewhere.

Blink gets a GA from me for beating me to it

Tom

Good. Wire is heavier 2 gauge which should be fine. I do like the idea of a dump load into a 12V water heater element. Basically free hot water after the bank is fully charged. Just make sure the element stays submerged ;-)

Your test of the connection at the other end of the bank or even in the middle should help. If the first battery still boils, then your wiring is good and that one battery needs help. If the battery nearest the new connection boils, your wiring/connections need work.

May be more effort than it is worth, but setting up high current +/- bus bars or a "star" wiring configuration (instead of the "daisy chain") might solve the problem.

An "all or none" charger will be ROUGH on your batteries. They will be much happier if you can find a charging scheme that provides a tapered top-off charge and then a reduced maintenance charge.

Best wishes.

If you receive direct current from the solar panels, and you are charging direct current batteries, why do you need an invertor before the batteries. Invertors convert dc into ac, and in setup using battery banks, the invertor should only be after the battery bank to supply your ac load; make sure you are not feeding alternating current to your batteries.

Yep the inverter is after the battery bank not between.

It could be that your battery cables are too light, or you could have loose/contaminated connections on the battery terminals. Is your regulator adjustable? Lowering the cut-in voltage to 12.3 V would help. Does the controller provide multi-stage charging? You may be trying to dump full charge current into the batteries while they are fully charged, when you should only be supplying a trickle "maintenance" charge. The water heater should help with this.

If you get the last three issues of Passage Maker Magazine (at your library), read it ALL, even though it is for a boat system and diesel engines. ESPECIALLY the part of the article describing the IN and OUT terminals for the battery bank and how they are determined and wired into the control system and to the inverters. You could take the LONG way and keep messing around or the short way and really know exactly why your problem is occurring. Please read the whole article. Boats are incredibly difficult to wire and ground and electrically protect. Studying such articles and nautical wiring books will give you much greater insight. Regards, mog (40' solar powered yacht)

Hi Blink,

GA to you Sir

Good luck

The best design for solar systems is to have high voltage and low current. Your system is the opposite. 41 amps of current is a lot and batteries in parallel can be an issue. Best to not have more than 2 parallel battery strings. How about if you reconfigured by putting your solar modules in series and the batteries in series and then fed your inverter? Most of this info is on line by the manufactures of your equipment.

The inverters and conttroller are all 12v input, that's why I went with the configuration. This is not a grid tied system or anything, infact I'm not on the grid at all even with this small system which I'm growing larger as money allows.

Thanks

Have you considered switching the number one battery with battery number five? See if the battery - formerly number five, now number one in the series, behaves the same way. Perhaps that would help begin the process of pinpointing a problem.