What does "topping up" refer to in EV charging practices?

"Topping up" refers to the practice of charging an electric vehicle (EV) to maintain battery health without allowing it to fully discharge. This approach is important in prolonging the lifespan and efficiency of lithium-ion batteries commonly used in electric vehicles. Unlike conventional charging where the intent is to fully charge the battery before use, topping up involves brief charging sessions often during idle times, which helps to keep the battery at an optimal state of charge. This method reduces the depth of discharge, ultimately contributing to better battery health and performance over time.

In contrast, fully charging an EV before use may not always be practical or necessary, especially if the vehicle is going to be driven only short distances. Charging during peak hours does not relate to topping up but rather concerns the cost and efficiency of charging schedules. Finally, charging multiple EVs simultaneously can be an aspect of charging strategy, but it does not define the topping up practice specifically.