Why are my sealed batteries fat or inflated

[4321loco]

I have 20 40ah sealed lead batteries and 6 of them are kinda fat on the sides, you can feel the side a little rounded.

All batteries show from 12-13 volts and hold a charge, some are from 1-2 years old....

Why would these batteries get like that, normal charge consist of a 20 watt solar panel on them every day, could it be they need a better charge controller or that they see to much volatge, we do have days that are cloudy and they drop to 11.5-11.9 volts but then a day or 2 later they are up again to 13 volts..

I would estimate the current draw to be at max of 400-500MA per hour all day long..

Well just curious why so many of these battiers get fat, or is this normalon sealed lead batteries

[DC Battery Specialists]

These are just overcharged. The plates inside the batteries have are now warped and that causes the battery to bulge. You have very low draw and it seems that over time some of the batteries are getting overcharged.

[4321loco]

Can the fat batteries still be used or is it safer to recycle them, I mean they are not really fat but I guess they were over charged a little or to much...

Anyways Would you recommend me to dispose of the fat ones and use the normal ones

Thanks for the answer

[DC Battery Specialists]

these batteries will have different capacity than your other not bloated batteries so it would not be suggested to leave them in the bank because it will eventually damage the healthy batteries that you have in your bank.

[4321loco]

these batteries will have different capacity than your other not bloated batteries so it would not be suggested to leave them in the bank because it will eventually damage the healthy batteries that you have in your bank.

Thank you so much...I will be sure to recycle them as I don't want to harm my bank once they are all tied in....They nice little batteries..

[Mike90250]

2 reasons sealed batterys bulge

1) Overcharge (fast) and pressure buildup, till vent relives pressure and you loose electrolyte.

2) Overcharge (slow) causes positive plate oxidation, and flaking, which expands cell.

may as well use them tilll they stop working, and then buy new ones. AND check your charge controllers settings, to match your battery style.

[4321loco]

2 reasons sealed batterys bulge

1) Overcharge (fast) and pressure buildup, till vent relives pressure and you loose electrolyte.

2) Overcharge (slow) causes positive plate oxidation, and flaking, which expands cell.

may as well use them tilll they stop working, and then buy new ones. AND check your charge controllers settings, to match your battery style.

Hey Mike so then In my situation these batteries were damaged to what...

They are 40ah batteries like 30lbs each, each had there own 20 watt panel, I am sure the electronics had a voltage regulator but maybe not as great I would suppose..

Or would those 20 watt panels over charge batteries to fast...Cause now we are replacing the 20 watt panels to 40 watts....Maybe this will be more of a problem

[Mike90250]

For sealed batteries, you need a QUALITY charge controller, that terminates the charge at the proper voltage. You need a remote temp sensor.

And you need to discover if you have sealed GEL or sealed AGM batteries. They are all different, and need to be treated differently by the charge controller.

Wait, I remember, there is a 3rd type of sealed battery - Low Matainance Auto battery, but nobody would try to use that in a solar application.

Sometimes in an older battery, the weight of the electroltye inside, causes the sides to harmlessly bulge a bit, but that's only flooded batteries, GEL or AGM should never have a bulge from weight.

[4321loco]

For sealed batteries, you need a QUALITY charge controller, that terminates the charge at the proper voltage. You need a remote temp sensor.

And you need to discover if you have sealed GEL or sealed AGM batteries. They are all different, and need to be treated differently by the charge controller.

Wait, I remember, there is a 3rd type of sealed battery - Low Matainance Auto battery, but nobody would try to use that in a solar application.

Sometimes in an older battery, the weight of the electroltye inside, causes the sides to harmlessly bulge a bit, but that's only flooded batteries, GEL or AGM should never have a bulge from weight.

These are specs off the internet...I have used my deep cycle chargers on AGM mode and at 2 amps, since that's the lowest I can put, it also has 10 and 15 amp more but I stay away In case that's to much for each one.




* 12V pure lead-tin VRLA AGM battery
* UL 94V0 flame retardant case and cover optional
* M6 female no-maintenance terminals
* Can be installed in any orientation except inverted
* Rugged construction (optional metal jacket)
* Approved for shipping as non-hazardous, nonspillable

Performance Features:
* Environmental resilience: -40

[Mike90250]

You need a 3 stage solar charge controller, if you don't want to kill your batteries. Something like the Morningstar SS-10 Solar Charge Controller. It's not a $15 harbor freight controller. you need a quality controller to charge batteries properly.

Read this article about solar charge controllers

http://www.windsun.com/ChargeControls/ChargeCont.htm

[4321loco]

Well not sure if Im off topic now but...

Ok, we got the batteries that were not bloated and charged them up to do a load test...

If the batteries are 12 volts 42ah lead acid and the others are 44ah gel..

What setting should be used to load them, I think load tested is a cheapo 500 amp load tested but I think the guys are running load test on 250amps for 1 minute on each battery and the batteries go down to like 7 volts other stay resting a bit higher....Is this incorrect, I taught the load test was a bit to much for these small batteries....I been looking every were but all load test I see are for car batteries tad bigger

[Mike90250]

If they are 42A batteries, I would use a 2A load, and then stop after 3 hours, wait 3 hours, and then measure voltage. This should be about 15% discharge, and after sitting for another 3 hours, you should be able to measure 85% remaining
2A x 3H 6AH . 42/6=7
with a standard voltage chart:

http://www.windsun.com/Batteries/Battery_FAQ.htm#Battery%20Voltages

scroll down a bit to the chart - should be about 12.45V

[4321loco]

If they are 42A batteries, I would use a 2A load, and then stop after 3 hours, wait 3 hours, and then measure voltage. This should be about 15% discharge, and after sitting for another 3 hours, you should be able to measure 85% remaining
2A x 3H 6AH . 42/6=7
with a standard voltage chart:

http://www.windsun.com/Batteries/Battery_FAQ.htm#Battery%20Voltages

scroll down a bit to the chart - should be about 12.45V

I used to test similar to this method....But at my job the guys say teh batts do like 500 cca, so they use half of that rating for 1-2 minutes were every were else I hear its suppose to be 15 seconds...

I am finishing charging me last batts and will do diffrent test tommorrow and some might go to my buddies shop see what he tells me..

Thanks for teh wuick reply

[Mike90250]

these are deep cycle batteries, not starter batteries. If you are using them for off grid, you should test them for that purpose. A 42AH battery will fail a automotive use test.

[SUNTRONENERGY]

Just remember that the damaged batteries are going to affect the performance of the entire bank....It is also not advised to parallel new batteries to old batteries. Within days, your new ones will be performing just like the old ones.