Battery not fully charged

batteries

#1

I have a 04 Saturn L300. The battery is not taking a full charge. The local Kragen load tested the battery and alternator. They said they are both good. But the Battery is only showing 300 cold cranking Amps instead of 600 it is rated for.

Symptoms: battery was too low to start car after playing CD Player while I washed and waxed car.

Battery gets too low to run CD palyer after playing CD for 10 minutes.


#2

I don’t know how they tested this battery or determined this cold cranking amps figure. The battery should be put on a battery charger for a minimum of .5 an hour (preferably an hour).
Then a load equal to 3 X the starter current draw (warm engine and usually about 300-350 amps) should be applied with a carbon pile for 15 seconds. (There are a lot of factors involved in the starter current draw so that is not a fixed figure.)
The battery voltage should not drop below 10.2 volts at a minimum. 10 volts or less means the battery is questionable; 9 volts means it’s junk for sure.

That’s the way it should be done anyway.


#3

With some monster amps that would be perfectly normal. Time for a new battery.


#4

sounds like a bad battery to me.

Car batteries can’t take a deep discharge very many times before they suffer permanent damage.