Leaving Lead Acid Batteries unattended for 6 months

[Usman]

I have 24 pieces of 900Ah/2V Deep Cycle Lead Acid batteries for connecting to a 48V - 5KW wind/solar Hybrid system. I got those off a military project, when they were still in use by them for another project, and they were given to me for use in another project.

It has been since 6 months these batteries are left unattended or not charged/discharged and haven't been even connected to a power source and load; just sitting there in a workplace waiting for the remaining components of the power system to be finished before they can be of any use.

Since now it's the time to get them connected, I was wondering if this period has caused any damage to them. They were some 2-3 years old and charged using two Morningstar 30A 24V charge controllers, when disconnected. They have been stored in an outdoor and relatively hot climate where temperatures range from 38-43 degrees during the day time.

I also noticed some blackish carbon like stuff floating in the acid, when shaken, falls apart from the top towards the bottom. Is that something falling apart e.g. the lead plates or is that something normal?

There acid is still above the 'min' indicated level.

I have included a picture for referral to the battery-type.

Any ideas on if they are still as good as when disconnected or if not, then what could be done to make them as good as when disconnected?

Thanks.

[kurt]

Usman i removed your comment because a 900KB picture is unacceptable we have a rule here that pictures must be under 150kb and less than 640 x 480 pixels or they will be removed please review the board rules http://www.fieldlines.com/special/faq then resize your photo and repost

thank you

Kurt

[bob g]

your batteries will self discharge over time, some are worse than others, but all will slowly go dead over time.

what is especially hard on them is how long they are allowed to sit at a partially or fully discharged state,, the sulfation that forms when a battery discharges will start to harden and crystallize.

you need to get them setup and on a charger asap!

the fact that they were stored in as you say a relatively hot climate only exacerbates their demise. (i assume you meant celsius?)

better get them on a charger, watered properly, and perferrably stored in a cooler place.

65-70 degree's  F. would be much more preferrable in my opinion,, cooler is not as harmful as warmer.

bob g

[Usman]

Thanks,

Is there anything that I could do to restore them up to their original condition? Or should I presume that they are already dead by now?

Thanks.

[Usman]

Ok,

Thanks and apologies! I will take that into account in the future.

Thanks, Usman

[wooferhound]

Measure the voltage

If they are still charged up then you are probably doing OK

I stored a car battery for 3 years in a garage, It was fully charged to begin with. I recently started using it again and it's just as good as when I disconnected it.

But like was said above, it would be good to go ahead and put the batteries on a charger and top them off as soon as possible.

Best way to determine if your batteries are still good?

http://www.fieldlines.com/story/2007/11/27/15439/980

[luckeydog]

All lead acid batteries start their count down the Minuit acid is introduced to the lead plates. Not using a battery for long periods is worse than using them. many lead acid batteries develop what is called a memory. and the original full potential of the battery is never achieved again.

 Luckeydog

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