Author Topic: battery ah  (Read 1391 times)

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windspeed

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battery ah
« on: September 17, 2009, 09:26:44 PM »
Advice wanted

I had 6 used 105 ah agm batteries 3 strings for 24 volts they were doing ok until one of them cracked its casing for no apparent reason

I have an older 350 ah agm battery whose capacity would be much reduced now could I use this with the single surviving  battery

I was thinking it would behave like a 105 ah battery because of its reduced capacity

Windspeed

« Last Edit: September 17, 2009, 09:26:44 PM by (unknown) »

Flux

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Re: battery ah
« Reply #1 on: September 18, 2009, 10:00:46 AM »
Normally no but as you are stuck you might as well try it but you will have to separate the 2 strings regularly and sort out the mixed string. I expect the big one will get undercharged. You may be able to equalise the whole string but I think I would fit the big one at one end of the string and use a lamp or a resistor to give additional charge to the big one every so often to keep it in step.


It's not an ideal situation but probably still better than using one string.


Flux

« Last Edit: September 18, 2009, 10:00:46 AM by Flux »

windspeed

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Re: battery ah
« Reply #2 on: September 18, 2009, 03:01:17 PM »
Thanks,

you said..

"use a lamp or a resistor to give additional charge to the big one every so often to keep it in step"

do you mean connect a resistance to drop the volts down to suit the big one and allow a small charge

could it be rigged like this continuously

Windspeed
« Last Edit: September 18, 2009, 03:01:17 PM by windspeed »

wpowokal

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Re: battery ah
« Reply #3 on: September 18, 2009, 06:14:10 PM »
Battery cases crack on older batteries because of expansion of the positive plates, in time it may bulge enough to short out but until then if you catch it quickly it's redeemable.


I use auto bog to repair the crack, refill with new acid and put it back to work, if you do not have acid on hand, refill with distilled water to preserve the plates until you source some acid.


I live with old batteries many now with repaired cases, my feeling is that the larger battery will be OK ( not normally recommended) just keep an eye on the SG (specific gravity) you may need to equalize for a little longer than normal.


allan down under

« Last Edit: September 18, 2009, 06:14:10 PM by wpowokal »
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