Open-Circuit Voltage Test

For accurate voltage readings, batteries must remain idle (no charging, no discharging) for at least 8 hrs, preferably 24 hrs.

   1. Disconnect all loads from the batteries.
   2. Measure the voltage using a DC voltmeter.
   3. Check the state of charge with the Table below
   4. Charge the battery if it registers 0% to 75 % charged

After charge, if the battery registers below the Temperature Compensated values illustrated in “How can you tell if a battery is fully charged” or “How can I measure my batteries State of Charge”, the following conditions may exist:

   1. The battery was left in a state of discharge too long.
   2. The battery has a bad cell.

Batteries in these conditions should be taken to a specialist for further evaluation or retired from service.