Electric vehicles are taking over the transportation market, and this meansthat the demand for high performing battery packs is also on the rise. Toensure that every vehicle meets our expectations for power output, chargingspeed, safety and lifespan, battery and car manufacturers both must test thebattery packs for. The open circuit voltage on any device is the voltage when no load isconnected to the rest of the circuit. In the case of a battery, the OCVmeasurement reflects the potential difference. Even though the modules and packs are made up of cells, the entire group canbe treated as a single larger battery and the voltage can be measured directlyacross those two terminals with a digital multimeter (DMM) as. Battery cells are connected in series to increase the voltage potential in the system. The current output remains the same across all the cells. Since shorts are less likely to cause a severe current event, fusing is not as critical as. Battery cells are connected in parallel to increase the current output in thesystem. In this case, the open circuit voltage remains the same across.