What Does Low Battery Voltage Mean In A Car. With the engine off you should get a reading of 126 volts. Amperes is the measurement for current.
When a car drops for instance from 126 to 120 there will be 75 difference. In most cases charging the battery or allowing the car to run for thirty minutes will reset the low battery warning message. 120 volts or below At 120 volts your battery is considered to be fully discharged or flat and should be recharged as soon as possible.
A fully charged car battery has 126 volts.
A low voltage also needs a recharge by itself before it is safe to run. 13 -14v is the average alternator output. Batteries should be left to settle for a while after charging so they will show a more accurate open circuit voltage. If the battery isnt fully charged it will diminish to 124V at 75 12V when its only operating at 25 and down to 119V when its completely discharged.
