Will they have survived??

[tom192]

I work in the warehouse at an asda superstore. We have had a machine that is used for pushing shopping trollys around left out in our warehouse yard for approx 12 months.

It contains 3 105ah exide deep cycle marine batteries wired in series to produce 36v.

Put the meter on it the other day and it read 30.5v.

Checked each battery in turn two gave a reading of 11.9v
and one was only reading 6.5v

Will they be recoverable or are they toast??

[ChrisBarron]

I work in the warehouse at an asda superstore. We have had a machine that is used for pushing shopping trollys around left out in our warehouse yard for approx 12 months.

It contains 3 105ah exide deep cycle marine batteries wired in series to produce 36v.

Put the meter on it the other day and it read 30.5v.

Checked each battery in turn two gave a reading of 11.9v
and one was only reading 6.5v

Will they be recoverable or are they toast??

The batteries at 11.9V may well be fine, the lower one I would be wary of.
The only way to find out is to check the SG of the acid if possible, or failing that just charge them.
12V with no attention will produce these results due to self-discharge, but as far as types of discharges go it isn't necessarily bad and a long slow charge with low current over a period of days could bring them back to what they could have been expected to be at before the lay-off period

[tom192]

Well i left it on charge from 17:00 wed and arrived at work at 16:00 on thurs and it was still trying to charge! the batteries were very warm and there had been some out bubbling of electrolyte.

The charger says on 5 stage 15amp battery charger on so im presuming its fully automatic but surly 24hours should have been sufficient?

I disconnected and allowed the batteries to cool and all batteries are now indicating 13.5v (bit high??)

There also appears to be a slight bubbling sound still being audiable, the batteries are still connected in series so is it possible that the weak pack is being charged from the two good packs?

[ChrisBarron]

Well i left it on charge from 17:00 wed and arrived at work at 16:00 on thurs and it was still trying to charge! the batteries were very warm and there had been some out bubbling of electrolyte.

The charger says on 5 stage 15amp battery charger on so im presuming its fully automatic but surly 24hours should have been sufficient?

I disconnected and allowed the batteries to cool and all batteries are now indicating 13.5v (bit high??)

There also appears to be a slight bubbling sound still being audiable, the batteries are still connected in series so is it possible that the weak pack is being charged from the two good packs?

Sounds like you're getting somewhere. The bubbling is normal, and bubbling after the charger has been disconnected is a good sign too because it means that a lot , if not all, of the plate area has producing gas and not overly contaminated with sulphate crystals. The bubbles continue to rise from the plates for a long time afterwards. You can give the batteries a knock or a tap to dislodge them whenever you walk past them which would also help

The real test now is to let them stand for twenty four hours to allow the voltage to sag back, hopefully to no less than about 2.1V per cell equivalent. That wiull give them a chance to cool down too. As long as the electrolyte level is adequate they could be saved

Chris

[ChrisB]

All good advice there

Sounds to me like the lower one has bit the dust to be honest and its causing the others to get rather cooked hence why the charger was still going

Leave them for 24hrs , then give them some loading and see if that low one dies if it does then just swap out that one, not idea as you'll have to add a brand new one into a set of part worns which will upset the pack to a degree.

Keep us up to speed with your findings

ChrisB

[tom192]

Im off work today so they will be all rested and ready to check when im in 2moro.

Only one cell in each battery needed some water in and it was only a tiny bit that it needed in each cell so hopefully theres some potential for recovery. Just need to investigate why the charger didnt turn off, my other option is to remove each battery and charge individually but my only charger avalable is a bog standard 12v car battery charger that charges at 4 amps - will this even charge a 105ah pack?

Hopefully someone has found the new key so that i can try and put some load on the batteries, (someone lost the old key in the first place and this is why it ended up dumped for 12 months!

[ChrisBarron]

Only one cell in each battery needed some water in and it was only a tiny bit that it needed in each cell so hopefully theres some potential for recovery. Just need to investigate why the charger didnt turn off, my other option is to remove each battery and charge individually but my only charger avalable is a bog standard 12v car battery charger that charges at 4 amps - will this even charge a 105ah pack?!

As t'other ChrisB said, if one cell is down in one battery then the other cells will be getting plenty of charge while the charger tries to raise the whole pack voltage. With a failed cell it is prevented from doing so because the whole pack will never reach the target voltage due to the failed cell keeping the total voltage too low.

A 4Amp charger would charge the cells at about C/25 which is perfect for float charging them and it will slowly but surely get the voltage up. nLoad testing them to see how low the voltage sags under load is your next indicator of health, and if the batteries seem poor it may be that after a few charge-discharge cycles their performance improves.

Chris

[tom192]

Well had the meter on again 2day after a good 36 hour rest all 3 batteries are still reading 12.8v so looks like they may have survived!

Havent had chance to put any load on them yet though so thats the acid test (no pun intended!)

Have plugged the charger back in and its switched itself over to maintainance charge so looks like that works fine too, have left it on maintenance for the time being until i can find the key or manage to hotwire the thing!

I do have a 12v flourecent tube that i may connect up and drain each battery and give it a recharge so that i can cycle them.

[ChrisBarron]

Well had the meter on again 2day after a good 36 hour rest all 3 batteries are still reading 12.8v so looks like they may have survived!

Havent had chance to put any load on them yet though so thats the acid test (no pun intended!)

Have plugged the charger back in and its switched itself over to maintainance charge so looks like that works fine too, have left it on maintenance for the time being until i can find the key or manage to hotwire the thing!

I do have a 12v flourecent tube that i may connect up and drain each battery and give it a recharge so that i can cycle them.

Well done ! That sounds good Tom, but ultimately the load test will tell you how you stand. I have a lead acid battery here which sits at 2.6V, either from contamination or pollution or for some other reason it reads a high voltage but gives next to no power and accepts very little charge current, so I would make a proper test a priority.

Chris