What Is The Charging Voltage For A 12v Battery. An fully charged 12-volt AGM battery should typically have a voltage of 127V to 130V when not connected to a load or a charger such a voltage is called the open-circuit voltage. Charging with 5V is prone to dangerous overcharging.
In reality the amount is not exactly 12 volt. The batteries are all less than 18 months old seldom discharged and not to less than 12V. Car Battery Voltage.
Some Automatic chargers often incorporate a temperature selection feature to account for temperature variations.
Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near 80-90 full charge level. I put together the following battery state of charge chart which indicates the state-of-charge percent as it relates to battery voltage or specific gravity. For 37V batteries the charge cutoff voltage is 42V and the discharge cutoff voltage is 30V so when the battery open circuit voltage is below 36V it should be ready for charging. All batteries should be fully charged after each use.
