A Battery Management System or BMS, for short, is usually a circuit board wired internally in the battery. These boards offer lots of different uses such as a fuel gauge, temperature monitoring, over-discharge/over-charge protection, and more. Whether you need a BMS or not and what kind of BMS you need will depend on the application because it can add weight to the battery as well. If you are looking for a BMS for your battery contact our battery tech team here and they can explain our options.