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Old 10-01-2004, 07:13 PM   #1
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12v lead acid battery charging question....

I've just got a new 12 battery to charge from and the battery is rated at 620 CCA (whatever that means), anyway it's been on a 4 amp charger for approx 12 hours but according to the hydrometer all the cells are still not charged.

The question is, some ppl have said 12 hours for a brand new battery should be enough and if it's not charged now it's a dud but others have said a brand new one would need like 24 hrs.

What do others think/opinions will be appreciated?
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Old 10-02-2004, 03:18 AM   #2
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Is it a leasuire battery or an automotive one?
If it's an automotive one, they are not designed for the high charge/drain usage we put them thru, so the life is probably only a season. A leasuire one will last much longer!

As to charging, it depends if it was charged when you got it...you ahve put in max 48A in 12 hours @ 4a. On a 110A battery, that's only almost 50%.

Give it a few more hours, I doubt a new battery is a dud, is the charger perhaps faulty?
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Old 10-02-2004, 05:26 AM   #3
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Quote:
Originally posted by TraceRacing
Is it a leasuire battery or an automotive one?
If it's an automotive one, they are not designed for the high charge/drain usage we put them thru, so the life is probably only a season. A leasuire one will last much longer!

As to charging, it depends if it was charged when you got it...you ahve put in max 48A in 12 hours @ 4a. On a 110A battery, that's only almost 50%.

Give it a few more hours, I doubt a new battery is a dud, is the charger perhaps faulty?
Well I'm not sure what class it would fall into, it's stated use is apparently for small truck use/cars with a lot of accessories.

It was flat when I got it and I'm fairly sure the charger is ok because it's the same one I use for real a car/motorcycle batteries and it charges them ok. I guess I didn't leave it on long enough by the sounds of things.

Last edited by Mabuchi540; 10-02-2004 at 05:41 AM.
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Old 10-02-2004, 09:14 AM   #4
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"It was flat when I got it."

If it had been sitting discharged for very long there is a good chance it will not recharge, or your charger doesn't have the ability to properly charge it.

First, check it's static voltage .. if it is below 4v, a typical home charger won't charge a battery this low. It's a fail safe in the charger to keep you from harming it. If it's below 4v, take it to a battery shop that can recharge it (not a auto parts shop!)

If the voltage is up, it just needs much longer before it will charge. A fully discharged battery like that should take anywhere from 24-48 hours at 2amps - but it may take 12-24 hours before it begins to accept a charge. So you're realisitically looking at a 24-84 hour charge cycle.

Leave it on a 2 amp rate until it starts to charge, once you see your hydrometer reading come up 25 points or so then you can switch to to a higher rate. Slower rate takes longer but will warm the plates up slower and reduce the chances of a dead cell.

Just keep an eye on it's temperature, if it's boiling or not, and keep checking it with your hydrometer. Use a swing-arm style hydrometer, the ball type are junk (really.)

The battery you have is probably 35-55ah. It's not a deep cycle battery, so like what was already said it won't handle being discharged and recharged as well. The best thing to do is to not let it discharge below 75% - this will greatly help keep it from doing bad due to cycling. You can get a lot of cycles out of a regular auto battery, but the chances of a cell not charging back up are greater if you cycle the battery below 75% discharge.

When this one goes bad, go buy a 12V 35AH AGM style battery. They are commonly used in wheel chairs and electric golf caddies - they can handle the cycling and best of all are completely sealed and easier to transport.

http://www.ibsa.com/estore/view_prod...0VXEG8XP8&js=1
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Old 10-02-2004, 09:33 AM   #5
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I race full size electric cars as another hobby, kinda through school. Anyhow, we put our 12v batteries through alot, but most of the time we trickle charge them on a "battery tender" for a week or so before we leave for the race, then we hit them harder on a regular NAPA styel charger on high. Only takes a few hours on the napa charger. Most teams even heat their batteries while charging at around 6 amps. It picks up 40% more charge according to them, but dangerous to be heating batteries.
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Old 10-02-2004, 10:28 AM   #6
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CCA = cold cranking amps. thats how many amps the battery is supposely putting to the stater motor first thing in the morning.
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Old 10-03-2004, 08:43 AM   #7
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If you want to be technical, CCA is the amount of amps delivered at 9.6v @ 0 degrees F.

Cranking ampers is at 32 degrees, and hot cranking amps is at 80F.

CCA / .4 = CA
CA * .65 = HCA

(roughly)

S.Stew, heating or hot charging (over charging) the batteries does make sense as they will take on a little more of a surface charge. I'm not sure if they can handle another 40% more of their capacity, but I could see it.

Speaking of heating batteries, I work in a batty shop and line charge 12-24 batteries at a time. Several times one or two has failed on the charger and the increased voltage to the others has gotten several hot enough that the plates in the battery have melted through the battery case. They were so hot that after letting them sit 9 hours they were still physically warm to the touch. Youch.
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