Its best to first check the total voltage of the battery pack. If the battery voltage is 68 volts or lower, then you know the problem. Connect a voltmeter to the positive terminal on battery #1 and the negative terminal on battery #6 to check total voltage. Batteries 1 and 6 are the two middle batteries towards the back. One is the passenger side and six is the driver’s side. If voltage is 68 volts or below the battery charger will not turn on. In this case you will need to charge each battery one at a time.
