4S 16.8 V BMS Design

I need a compact Battery-Management System for a 4-cell Li-ion pack that reaches 16.8 V at full charge. The board must integrate every key safeguard: over-charge, over-discharge, short-circuit, thermal cut-off and reliable cell-to-cell balancing.

My priority is proven safety, so component choices and threshold values have to follow industry-standard limits for 18650 chemistry. If the design relies on a dedicated BMS IC, please include the configuration worksheet or register map; if you prefer a small MCU, I’ll need clean, well-commented firmware as part of the package.

Deliverables
• Complete schematic in Altium, KiCad or EasyEDA
• PCB layout with ready-to-fabricate Gerbers (180x65x1 mm target size)
• Annotated BOM with ordering links and footprints
• Brief design note explaining protection timings, balancing method and thermistor placement
• (If firmware is used) source code and hex file, plus flashing instructions

I will test the first prototype on my side; acceptance is achieved once the board disconnects or throttles exactly at the specified voltage, current and temperature limits and equalises the cells within ±10 mV. Feel free to suggest either passive or active balancing if it improves performance without adding excessive cost.