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Is my battery toast?


jimy

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Last week I got my 1935 Dodge KCL pickup out of storage after being there a little over 18 months.  When I arrived I was somewhat surprised the battery (6 volt) was fine (hadn't been on a charger).  At the storage place, it took me a while to get it going - turned out the carb needle valve was stuck.  I did a lot of cranking to get it going and the starter never slowed down. 

 

I drove it 10 minutes home and then a 10 mile round trip for an inspection several days later.  No problem.

 

Yesterday I was trying to improve the vacuum wipers so I started it 6-8 times - very little compared to the initial start the other day.  The battery got weak during this.  I saw 6.1 volts at the battery (key off - not running for this).

 

Put it on a 1 amp trickle charger yesterday - the charger got pretty warm and it didn't help the battery.

 

So I put it on a good old fashioned charger.  It sat at 7 amps for a while so I left it and it was close to 10 amps two hours later.  After that, it still wouldn't crank successfully.   The big charger was getting pretty warm too so I'm not too happy about running it all night.  In my past experience I could usually start a car after 2 hours on a charge and most certainly the starter would spin better after an hour or two of charging - not this times.

 

Has anyone seen a battery failure like this?  Basically a battery with full charge that won't recharge after being run down.  Did my electrons fall out?  🙂

 

Jim

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Positive ground on a Dodge, you did have it hooked up the right way, right?

 

IMHO Check the water, add distilled water if the plates aren't covered, and put it back on the charger as soon as possible. A shorted cell could make it get hot and draw too much current, but your description doesn't sound like there was necessarily a problem.

 

When using a conventional (not "smart" or "modern") charger of about 6-10 amps or so, a completely dead battery, one that is way lower than it should have ever been allowed to get, won't draw much current at first. It is because the internal resistance of a really dead battery is so high. The charger will struggle to do anything. Slowly the current will come up as the battery gets some charge in it and the internal resistance goes down. When the battery getting halfway or more charged, the current will start to drop again because although the internal resistance is low now, the voltage of the battery is getting closer to the charger voltage, and less difference results in less current flowing. It gets pretty low when the battery is fully charged.

 

So yeah, the current goes low-high-low as you charge a dead battery. If it was still high, you weren't near done. I am talking about an old fashioned metal lunchbox sized charger here, not some huge roll-around 50 or 100 amp unit meant to boost or jumpstart cars. If you have one of those, it is about the same deal, but make sure you have it set on "low" or "slow" charge.

 

If the battery has enough water, and the battery is not getting hot or stinking, let 'er rip.

 

Edited by Bloo (see edit history)
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Thanks. Yes, the polarity is correct.  And it is a lunch box sized charger. 
 

there is plenty of water over the plates so I added no water.   But speaking of that, what is up with one of the 3 fill holes being plugged up with what looks like styrofoam?  That cap is different as well. 
 

I will run the charger until I go to bed.  I’m a bit nervous to keep it going overnight.  
 

thanks

 

Jim

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What? Take a picture. I have no idea. I've never heard of anything like that. You should be able to take off all 3 caps and look down to the water over the plates in all 3 cells. If you cannot, something must be really wrong.

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