A battery management system (BMS) for use in hobby projects utilizing lithium batteries. This BMS allows users to manage the charging and discharging of a battery pack. It is adaptable to work with a variety of series and parallel cell configurations and chemistries to accommodate different project needs. Designed with hobbyists in mind, this system costs a reasonable price and allows for some degree of customization. Engineering Requirements: 1 The BMS will stop a battery pack from overcharging or over discharging when either an individual cell voltage is out of a safe range or the total pack voltage is out of a safe range. This requirement is met. 2. The BMS will be usable with at least two battery chemistries separately. This requirement is met. 3. The BMS will be compatible with a range of cell configurations from as low as a 12 volt nominal battery pack to as high as a 48 volt nominal battery pack. This requirement is met. 4. The BMS will allow pack configurations with at least two cells in parallel and will be implemented with a custom PCB. This requirement is met.