The best way to obtain health information on your batteries is to perform a load test from a fully charged state using a load bank/discharger.
Most battery manufacturers recommend discharging batteries until they reach 1.75 volts per cell. On a 48 volt system, whether a golf cart or a motive battery, you should discharge the pack until it reaches 42 volts (1.75 x 24 cells). While the load test is being performed, it is proper procedure to take voltage readings (of each individual cell or battery) periodically and record them. The “old school” way is to do this with a volt meter, manually writing down the readings. Today, there are battery monitoring sensors available that can record voltage automatically, creating a load test with greatly reduced labor. If certain cells or batteries measure significantly lower than the rest of their counterparts, you know you probably have an issue. The capacity of the battery pack can be calculated based on the amp hour rating, the current applied, and the length of time it took to reach an average of 1.75 volts per cell. Don’t make the mistake of running the load test for a short period of time and assuming the battery pack will draw down at a linear rate, until it reaches the desired voltage. Yes, there are other things to consider when evaluating the health of a battery, but a load test is probably the most useful.
Visit our website to learn more about Battery Monitoring Sensors and how they can assist with testing your batteries.