The BPS is a simple single-cell battery protection board, designed to use commonly available components for this task. It uses DW01-type chips for the controller, and SOIC-8 dual MOSFET packages for control. Only two resistors and one capacitor complete the bill of materials.

The main goal of this project was to add single-cell battery protection to salvaged lithium cells from larger packs. It isn't designed to be a drop-in replacement for other BPS boards. It doesn't do any kind of thermal limiting either - as is common for DW01-type battery protection, it only triggers on voltage and current, and the limits are dependent on the particulars of the devices you choose.