6th October 2019


What should voltage be when car is running?

Less than 14.3 would be a "weak" alternator or regulator. If you measure battery voltage and it is anywhere over 14.2 volts and less than 14.8 volts with the car running at slow cruising engine RPM speeds and maximum loads on, you already have a bigger alternator than you need.

Keeping this in consideration, can you test a car battery?

Fully charged automotive batteries should measure at 12.6 volts or above. When the engine is running, this measurement should be 13.7 to 14.7 volts. If you don't have a multimeter to tell you the voltage of your battery, you can do a test of your electrical system by starting the car and turning on the headlights.

How many volts is a 12 volt battery fully charged?

For instance, a 6 volt battery will have 3 cells (3 x2.2= 6.6 volts), a 12 volt battery will have 6 cells (6 x2.2=13.2 volts) and so on.That 2.2 volts is the fully charged, straight off the charger number.
Write Your Answer


86% people found this answer useful, click to cast your vote.

4.3 / 5 based on 3 votes.


Press Ctrl + D to add this site to your favorites!