Lithium-ion batteries do not require a BMS to operate. The BMS is what prevents your battery cells from being drained or charged too much. Many assume "all lithium batteries must have a BMS," but in practice, some lithium batteries can operate without one—though such "exceptions" come with strict constraints and inherent risks. This is. A BMS monitors voltages, currents and temperatures, protects against overcharge, deep discharge, short circuits and unsafe temperatures, and balances cells to maintain capacity. Lithium cells require BMS protection because of narrow voltage limits, cell imbalance in multi-cell packs, and risk of. Not all lithium batteries come with a BMS. Specifically, like the 18650 cylindrical cells or lithium iron phosphate (LiFePO4) prismatic cells that often use in engineering projects, these raw cells are pure chemical containers when they leave the factory without any protection circuit inside. Overall, a BMS enhances battery reliability and safety during charging and. This chapter describes things to consider on how the battery interacts with the BMS and how the BMS interacts with loads and chargers to keep the battery protected.