Lead Acid question.

[LA OZ]

I ve just recently bought this 2,500,000 candles bright light (cheapo one) and it is dead. I opened it up and inside, it has two Lead Acid batteries in serial rating as 6V 2.8V each. I attempted to charge it with my Triton and it won't kick off. I checked with a multimeter. It registered 4.6V for one and 0.6V for the other. So is it dead? I have used it for less than 20min.

 

[Brighteyez]

The one measuring .6V has had it. You might be able to revive the 4.6V one.

 

[LA OZ]

How to I revived the 4.6V as I set the Triton to 0.1amp and 6V charge (lowest setting). It won't go.

 

[Brighteyez]

A 6V lead acid is normally charged at about 6.8-7V. You might want to use the info at http://www.batteryuniversity.com/partone-13.htm as a guide.

The 4.6V reading that you got on that battery pretty much puts it at questionable at best, and it's probably suffered some cell damage being discharged that low. If it doesn't take a charge, I'd write it off. Having been discharged so low, you're probably better served replacing both batteries anyway.

Those handheld spotlights, don't have a lot of run-time and the batteries should be charged immediately as soon as any dimming is noticed. Unlike NiCD or NiMH batteries, SLA and lead acid batteries (like your car battery) should be kept fully charged as much and as frequently as possible.

 

[LA OZ]

You are right. There is no protection circuitry in the unit. I believe the light was accidentally bumped and the switch was turned on during storage.

A 6V lead acid is normally charged at about 6.8-7V. You might want to use the info at http://www.batteryuniversity.com/partone-13.htm as a guide.

The 4.6V reading that you got on that battery pretty much puts it at questionable at best, and it's probably suffered some cell damage being discharged that low. If it doesn't take a charge, I'd write it off. Having been discharged so low, you're probably better served replacing both batteries anyway.

Those handheld spotlights, don't have a lot of run-time and the batteries should be charged immediately as soon as any dimming is noticed. Unlike NiCD or NiMH batteries, SLA and lead acid batteries (like your car battery) should be kept fully charged as much and as frequently as possible.

 

[Calina]

This charger has the ability to recharge dead batteries among other things.
Maybe you would like to give it a try.

http://www.tunecharger.com/perso-25518.htm

More info, here.
http://candlepowerforums.com/vb/showthread.php?t=140058

 

[LA OZ]

That is a lot of money to rescue my two lead acid.

 

[eluminator]

In my experience, cheap spotlights come with cheap batteries. If a lead-acid sits around not fully charged, it will lose some capacity permanently.

Those batteries probably didn't have much capacity to begin with. The good news is you can buy better batteries cheap. The bad news is the shipping charge for those heavy things exceed the price of the batteries.

 

[LA OZ]

In my experience, cheap spotlights come with cheap batteries. If a lead-acid sits around not fully charged, it will lose some capacity permanently.

Those batteries probably didn't have much capacity to begin with. The good news is you can buy better batteries cheap. The bad news is the shipping charge for those heavy things exceed the price of the batteries.

Yes, the torch was sitting in the cupboard unused for 6 months and was not fully charged. I gave up the idea of restoring it. I am salvaging wires and parts from the torch for other usuage.

 

[Norm]

Hi LA, Radio parts caries SLA batteries, or you could try Super Cheap Auto, not too sure about super cheaps quality.
Norm

 

[hopkins]

I know its silly to suggest putting a motorcycle type battery into your
spotlight but seems availability is the issue! Would just have to keep
it upright all the time to prevent spilling electrolyte, a small pain for getting
your light working on the cheap. Assuming it would fit inside...

 

[lctorana]

Norm beat me to it.

Try Radio Parts.

 

[Fallingwater]

I know its silly to suggest putting a motorcycle type battery into your
spotlight but seems availability is the issue! Would just have to keep
it upright all the time to prevent spilling electrolyte, a small pain for getting
your light working on the cheap. Assuming it would fit inside...

Small pain? The first time you bump it you'd get acidic solution all over the internals of the thing. Flooded lead acid batteries are good for vehicles, fixed power supplies and nothing else.

I'd toss the SLAs and replace them with a 10S pack of NiMH C or D cells.

 

[lctorana]

I'd toss the SLAs and replace them with a 10S pack of NiMH C or D cells.

But at more than five times the cost!

 

[jzmtl]

Get an optima (or any similarly constructed batteries) to replace them, you can turn it upside down all you want.

 

[Fallingwater]

Five times? Ouch... I admit I didn't check the prices of C/D NiMH cells.

Maybe a maintenance-free flooded battery? Those should be splash-proof...

 

[lctorana]

SLAs are cheap at Radio Parts.

It is then a question of sparing use.

If you keep the DoD to 20% or so and recharge soon after, SLAs are fine, even at high discharge (within the nameplate limits).

I agree that NiMH is far better, but spending $180 on batteries for a $30 torch makes no sense.

Not that it has to, mind...

 

[NeonJohn]

I ve just recently bought this 2,500,000 candles bright light (cheapo one) and it is dead. I opened it up and inside, it has two Lead Acid batteries in serial rating as 6V 2.8V each. I attempted to charge it with my Triton and it won't kick off. I checked with a multimeter. It registered 4.6V for one and 0.6V for the other. So is it dead? I have used it for less than 20min.

You can probably bring them both back to life. All you have to do is get enough charge into each battery so that your charger will kick off.

All you need is a source of 12 volts such as a car battery or another SLA and a lamp that will pass a few amps. A 55 headlight lamp will work fine. So will the lamp that is in this light.

Simply connect the 12 volt battery through the lamp to each 6 volt battery individually. The lamp should initially light fairly brightly but will quickly dim. The battery that is completely flat may take a few minutes to start accepting current so the lamp may initially be out but should gradually brighten over several minutes.

After the battery starts accepting current, monitor its voltage and disconnect when it reaches about 6.5 volts. This should take no more than 5-10 minutes. Then transfer it over to your smart charger.

If the completely dead battery won't accept any current after 5 or 10 minutes, try connecting it BACKWARDS through the series lamp for no more than a minute or two. This process is sometimes necessary to break through the hard sulfate coating that forms in a battery that has been totally discharged for a long period.

Disconnect the reverse hookup as soon as the series lamp starts glowing. Then connect it as described above and charge through the lamp until the voltage is above 6.5 volts.

It usually takes several charge/discharge cycles to recover the maximum capacity that is possible. The battery is damaged and will have less capacity than new but it can still be recovered and used for quite a long time. I usually put several cycles on such a battery in rapid succession.

It also helps to hold the battery at its specified float voltage for several days. The hard sulfate crystals that formed while the battery was dead take awhile to convert. Holding at the float voltage for awhile gives them time to do their thing.

John