Lead Acid Battery Drain and Reuse

[David Halloran]

Does anybody know if a standard lead acid battery can be carefully drained of its electrolyte ( and the electrolyte stored in a safe place) and the battery then kept in a dry state only to have the electrolyte added back again and the battery brought back to a charged state after say a year or two? With Thanks

[delmarrey]

Yes it can be done.
In the good ole daze we use to rebuild batteries;
We would drain them.
Flush them out with fresh water and soda.
Flush them again with just fresh water.
Dry them out and knock then around a bit then dump out any flakes.

Then add new acid and charge them up.
If they held up to a Christie tester under load for 1 minute, then they were sold with a one year warranty.

The cells have to have enough lead to take the cleaning.
BTW -just dump the old acid and buy new from a battery shop.

[noelex 77]

If you do this David wear some good protective clothing. I have seen a number of serious eye injuries from battery acid. It usually the amateurs that get into trouble (usually making sinkers).

[David Halloran]

Many thanks for advice guys. I was sure it must be possible as I did it with a small motorbike battery and it worked.

My problem is that my boat has 15 6V LA batteries in 3 banks but it is left for many month unused. I don't really like leaving live batteries on her. Nor do I want to exhaust them doing nothing.

I'd really like some cost effective batteries that I can use when I need them and not when I don't.

But is that really a practical possibility?

Problems are how to quickly and safely remove electrolyte; how to safely store it or dispose of it; where to get and store new battery acid; how to test the battery is OK one new acid is put in; where to buy good quality old style batteries that can be opened and drained or topped up as necessary.

I am thinking that maybe truckers might have some solutions to these sorts of issues.

Finally what about old style batteries and fumes? Such batteries must have been used on boats in years gone by and I am wondering how fumes were detected if present and how over charging and gassing were controlled for.

[delmarrey]

Originally Posted by David Halloran

Many thanks for advice guys. I was sure it must be possible as I did it with a small motorbike battery and it worked.

My problem is that my boat has 15 6V LA batteries in 3 banks but it is left for many month unused. I don't really like leaving live batteries on her. Nor do I want to exhaust them doing nothing.

I'd really like some cost effective batteries that I can use when I need them and not when I don't.

But is that really a practical possibility?

Problems are how to quickly and safely remove electrolyte;
We had a special deep plastic pan with a screen to keep the battery from falling thru. And we'd just slowly roll the batter over (after cleaning off the outside). At the bottom was a drain to dispense it into containers.
And yes! Do wear full wrap safety glasses and synthetic clothing. The old Texaco uniforms were wool just for this reason.

how to safely store it or dispose of it; The containers must have an air tight lid and should be stored in a cool shadowed place, basements work good. Dilution is the solution to pollution! The farmers in Arizona use it in their fields to prevent moss growth.

where to get and store new battery acid;
Battery shops keep barrels of the acid.

how to test the battery is OK once new acid is put in;
It has to be fully charged first and then load tested. I use a christie tester (picture below)

where to buy good quality old style batteries that can be opened and drained or topped up as necessary.
I've been using Interstate for many years with good results. Marine Deep-Cycle/Starting Batteries

I am thinking that maybe truckers might have some solutions to these sorts of issues. No more then anyone else.

Finally what about old style batteries and fumes? Such batteries must have been used on boats in years gone by and I am wondering how fumes were detected if present and how over charging and gassing were controlled for.

Battery compartments are to be vented to the outside! See link CFR's 183.420 Sub C >>> http://www.gpo.gov/fdsys/pkg/CFR-200...sec183-420.pdf

.

[boden36]

Hi David,
You can do it but it is messy and dangerous, and you will inevitably do some damage to the battery internals, not to mention your back and the occasional squashed finger!. Far better to set up some solar panels with a regulator. This will trickle charge them and they will last as long as if you were using the boat regularly. I am often away from our boat for three months at a time and this works very well for me.
Regards,
Richard.

[djmarchand]

If all you want to do is to store long term a set of batteries on your boat, then charge them to the top and then disconnect them at the terminals to avoid discharging by parasitic losses on the boat.

This procedure will probably work for 6 months and will work nearly forever if you charge them to the top every 6 months.

No need to remove acid.

David

[btrayfors]

Originally Posted by djmarchand

If all you want to do is to store long term a set of batteries on your boat, then charge them to the top and then disconnect them at the terminals to avoid discharging by parasitic losses on the boat.

This procedure will probably work for 6 months and will work nearly forever if you charge them to the top every 6 months.

No need to remove acid.

David

David,

Unfortunately, if these are flooded lead-acid batteries your prescription will only work if the batteries are stored in very cold temperatures, i.e., near freezing.

Otherwise, with normal temperatures the batteries will discharge at a significant rate (often 3-6% per month) and will sulfate badly. This will greatly reduce their capacity. Do it once or twice and you will kill the batteries.

In the past when I had to leave my boat in the tropics for long periods I managed to kill several sets of Trojan T-105's; it only takes a few months!

Gels and AGMs have a much lower self-discharge rate and would survive this treatment much better.

However, the best prescription is to keep them fully charged, either with a smart charger or with a solar panel connected to a good multi-stage charge controller.

Bill

[foggysail]

Originally Posted by delmarrey

Yes it can be done.
In the good ole daze we use to rebuild batteries;
We would drain them.
Flush them out with fresh water and soda.
Flush them again with just fresh water.
Dry them out and knock then around a bit then dump out any flakes. How long did it take for them to just dry out?

Then add new acid and charge them up.
If they held up to a Christie tester under load for 1 minute, then they were sold with a one year warranty.

The cells have to have enough lead to take the cleaning.
BTW -just dump the old acid and buy new from a battery shop.

INTERESTING!!! Did you take the batteries apart to do this? If you just drained/flushed/ dried and then banged them about followed by trying to shake out flakes, would not the flakes get caught up between the plates? How long did it take to just dry them out?

Did this method work on sulfated batteries?

OH-- as to the OP's idea of draining, that is a lot of work! There are 15 batteries that need to be disconnected, hauled, dumped and reinstalled. Big job!

[delmarrey]

Originally Posted by foggysail

INTERESTING!!! Did you take the batteries apart to do this? If you just drained/flushed/ dried and then banged them about followed by trying to shake out flakes, would not the flakes get caught up between the plates? How long did it take to just dry them out?

Did this method work on sulfated batteries?

OH-- as to the OP's idea of draining, that is a lot of work! There are 15 batteries that need to be disconnected, hauled, dumped and reinstalled. Big job!

Back then the batteries had tarred-in cells, but no, dismantling is overkill. The dry out period took about a week with a fan blowing over them. The flakes would come off around the edges of the plates and usually not very big. If a lot came out it was a good indicator that the battery was about gone and it went in the heap to be recycled.
They were usually tested before draining.