Using a digital multimeter, you measure voltage by connecting the red probe to the battery's positive terminal and the black probe to the negative terminal, then reading the voltage displayed. Start by switching off all electrical components for safety and locate the battery. Ignoring battery health can lead to stranded vehicles, malfunctioning electronics, and the premature replacement of. . To check battery cell voltage, you use a digital multimeter to measure the voltage across each individual cell terminal. This simple process reveals the health and charge status of each cell, helping you identify underperforming or failing cells before they cause bigger issues. Call 1-800-929-7947 option 5 or +1-407-732-2000 extension 2510 for this issue or any other questions. Ensure the battery temperature compensating Thermistor is connected to the UPS module “Temp Sensor”. .