Why is my 12 volt car battery reading 21 volts and not starting?

W

wiredamerican

New member
Joined
Jan 6, 2009
Messages
1
Reaction score
0
Points
1
My starter in my vehicle will not turn over without a jump. My battery voltage reads 21 volts. I know it should read 12-14 volts. Is it possible there is too much voltage and not enough amperage? My alternator is putting out 14 -15 volts. Could this have anything to do with a battery freezing in cold temperatures? 20 or 30 degrees?
 
Make sure your battery tester is set in the 12 volt range. If you use the 6 volt range, it will reflect higher amounts. This would not make the battery freeze. You should have it tested properly and replace it, if needed.
 
I have never heard of this. Is it possible you had the dial turned down one notch too low on a digital multi-meter and your battery really had 2.1 volts? Sounds likely.
 
Back
Top