Bad battery?


#1

The car was dead, totally. I decided to charge the battery. The charger kept pegging the needle at max, then going off, then back on again repeatedly. Looks to me like a dead short. It is not the charger–works fine in another car. So, when batteries fail, do they often develop a total internal short?
Or should I be worrying about something in the car?


#2

I had 2 batteries do this to me.


#3

I don’t know about often, but certainly they do. Batteries are shot when they won’t take or keep a charge. Sounds like NAPA now gets their batteries produced by East Penn so the quality is better. Not sure who makes Delco now but bought one of each a couple weeks ago. Its that season.


#4

Duh! I disconnected the cables, and tested the car and the battery. The problem was the car. Duh! Struck a blow against Alzheimers.


#5

Happens…and this refers to both the battery question… and the Alzheimer’s comment.

Blackbird


#6

Hopefully you figured out what the problem was with the car. A bad alternator is about the only thing I could see causing that much current draw to happen. Unless a power wire got shorted somehow.

Car batteries have 6 cells tied in series to make up the 12 volts. Sometimes one of the cells can develop an internal short and that causes a real problem. The clue is when the battery voltage drops down to around 10 volts and doesn’t get any higher if you try to charge it up. It will also draw a lot of charging current due to the shorted cell.


#7

There must be a good reason why Melott won’t share what was wrong with the car. The solution might help someone someday.


#8

Don’t worry @mellot. We wont worry until you try stuffing a fork full of mashed taters into your ear.

Yosemite


#9

@volvo v70 Duh. I would think that you could figure out that I don’t yet know what is wrong with the car, except that there is a direct short across the cables when they are not connected to the battery. Whenever this does get traced down, I will report back on here.

I have also observed that with the battery disconnected from the car, it won’t seem to take any charge. I suppose it might have been damaged by sitting for a week or more tied into that short.

Anyway, I will be having a mechanic search for the short, so don’t get yer panties in a bunch if you don’t hear from me real soon.


#10

I once had a battery that was totally dead. I put a charger on it and the ammeter stayed at zero. Didn’t bother to disconnect it and walked away from it. An hour or two later I came back and low and behold it was taking a charge at the full capacity of the charger.


#11

I have seen batteries that pegged the needle on the charger & caused the charger to kick off , after a while the charger would kick back on & then back off . Left this way for a while & came back to find the battery charging .