In the right corner it's....Sir Gawain! He is nephew to King Arthur, and an honorable knight of Arthur's Round Table. He is very popular with the ladies, and quite charming. He is loyal to his king and queen and keeps his promises.
To charge the battery, the alternator voltage output has to exceed a minimum charging voltage. This minimum charging voltage is 13.8 volts dc across the battery terminals, or at the output of the alternator. A single lead-acid cell starts to charge at anything over 2.25 volts.ince a 12 volt battery has six cells, any 12 volt lead-acid battery needs at least 13.8 volts to start to charge. This voltage will be enough to fully charge or maintain the battery on a trickle charge, but charging time will be very long at 13.8 volts.
If the alternator is bad, your car or truck will eventually die out again as the battery is not re-charged. Get a good-quality voltmeter or multimeter and test your batteryâs state of charge. The voltmeter should read around 12.6 volts with the engine off and 14-15 volts when the engine is running. If voltage is below 13.5, thereâs a good chance the alternator is not keeping up with your batteryâs charging needs.