How To Tell What Voltage A Battery Is. Over-charging above 42V could be dangerous and eventually cause fire9 thg 1 2018. Test the battery voltage.
To get a true voltage reading of the cars battery it is important to measure the voltage after the car has been sat for a period with the engine off preferably overnight this provides you with the car battery open circuit voltage or also know as the resting voltage. 8 volt battery X 6 total batteries 48 volt system. Even a slight difference from the figure 126 volts does matter.
Touch the red negative - wire of the voltmeter to the red negative terminal of the battery.
It is the voltage between that node and the reference node. If it reads 120 volts or lower thats a sign that the battery. The terminals will be marked and -. Turn off the ignition and any accessories like lights or the radio in the vehicle.
