A bit OT but need your advise

[Bill I.]

I have 2 lead acid backup batteries for my home alarm 12v. 5 AH. Been neglected since 06. Checked the voltage today, 1 is 4.85, other 5.5 on the vom. Do you think I can bring them back?
Intend to try charging tomorrow using a 4 amp charger. Thanks, Bill. PS the batteries are sealed.

[Stephen L.]

Re: A bit OT but need your advise

Doesn't hurt to try, but the voltage is pretty low. May not hold a charge very long. If you need new ones these are typically the same as the brake battery on trailer electric brake emergency power. You may get a better price at Northern Hydraulics or similiar outlet.....

[Joe L.]

Re: A bit OT but need your advise

I have 2 lead acid backup batteries for my home alarm 12v. 5 AH. Been neglected since 06. Checked the voltage today, 1 is 4.85, other 5.5 on the vom. Do you think I can bring them back?
Intend to try charging tomorrow using a 4 amp charger. Thanks, Bill. PS the batteries are sealed.

Bill-----


It's very hard to say if they can be brought back; batteries are, in many ways, more like an art than a science. If it were me, I think I'd use a 1-2 amp charger, put it on the batteries and let it go for awhile. Then, test them. If they come up to voltage, then try them out and see if they hold a charge over time. You have nothing to lose. If they're shot, you buy new ones which is exactly what you do if you just decide now that they're shot.

My guess regarding the liklihood that you'll be able to "bring them back"? VERY near ZERO.

[Bill I.]

Re: A bit OT but need your advise

Joe, when you say let them go for a while what do you mean in hours? Only charger I have is 4 amp so that what I have to use. I'm thinking 12 hours and then check voltage, agree? Thanks, Bill.

[Joe L.]

Re: A bit OT but need your advise

Joe, when you say let them go for a while what do you mean in hours? Only charger I have is 4 amp so that what I have to use. I'm thinking 12 hours and then check voltage, agree? Thanks, Bill.

Bill-----


I'd do just that with what you have. Let it go 12 hours and check it. If they're not up, let them go another 12 hours and check again. If they're still not up, it's probably a waste of time, but you could let them go another 12 hours. There's nothing to lose.

We used to use similar batteries for our field sampling and flow monitoring equipment. I found nicad batteries to be worthless as far as longevity was concerned, so we switched to sealed lead acid. These were much less expensive and lasted a lot longer than the nicad. But, they are not "forever". When you can't get them to full voltage on a charger in 12-24 hours, that almost always means they're shot.

[Terry M.]

Re: A bit OT but need your advise

Some of the battery maintainers, the units that are designed to monitor battery voltage and shut off when it is fully charged, have the capability of reducing sulphation. It might be worthwhile to try one of these units rather than a regular trickle charger. Read the item description to be sure it is designed to control sulphation -- not all of them are.

[Jack H.]

Re: A bit OT but need your advise

I agree...a low probability 'fix'. But, back in the days of non-sealed lead acid batteries the GM service literature listed a low probability fix that would work 'occassionally' -- SHOCK charging.

The idea was to 'burn off' sulfite and oxidization from the plates by 'shocking' them electrically. The proceedure went this way...

Take a battery that won't take/hold a charge and HIT it repeatedly with short ON/OFF bursts on a high output battery charger (50-80 Amp output). Flip the switch from OFF to CHARGE for approximately one minute with several minutes of OFF between shock cycles.

Do this eight times or so, then return to slow/normal charging and see if you got 'lucky' in terms of ridding the internal plates of surface crud... Even then, the service literature cited this technique as a 'maybe' fix!

[Stuart F.]

Re: A bit OT but need your advise

I had a similar situation with my system's battery. I went out and bought a new one at my local Home Depot, then I put the old one on my Battery Minder using the sulphate feature. After about a 24 hour charge, it looked so good I replaced it back in the system to see if it would hold up. That was two years ago and it is still going strong, and the new one is the backup.

Stu Fox