How to Tell Which Golf Cart Lithium Battery is Bad？

1. Check Battery Management System (BMS) Alerts: Lithium batteries often come with a BMS that monitors the cells. Check for any error codes or alerts from the BMS, which can provide insight into issues like overcharging, overheating, or cell imbalance.
2. Measure Individual Battery Voltages: Use a multimeter to measure the voltage of each battery or cell pack. Healthy cells in a 48V lithium battery should be close in voltage (e.g., 3.2V per cell). A cell or battery that reads significantly lower than the rest may be failing.
3. Assess Battery Pack Voltage Consistency: After fully charging the battery pack, take the golf cart for a short drive. Then, measure the voltage of each battery pack. Any packs with substantially lower voltage after the test likely have capacity or discharge rate issues.
4. Check for Rapid Self-Discharge: After charging, let the batteries sit for a while and then re-measure the voltage. Batteries that lose voltage faster than others when idle may be deteriorating.
5. Monitor Charging Patterns: During charging, monitor each battery’s voltage rise. A failing battery may charge unusually fast or show resistance to charging. Additionally, if one battery heats up more than others, it may be damaged.
6. Use Diagnostic Software (If Available): Some lithium battery packs have Bluetooth or software connectivity to diagnose individual cells' health, such as State of Charge (SoC), temperature, and internal resistance.

If you identify one battery that consistently underperforms or exhibits unusual behavior across these tests, it’s likely the one that needs replacing or further inspection.