Smart Bluetooth 7S-20S Lifepo4 li-ion Battery Protection Board Set BMS 200A 48V Features: The PCB uses anti-corrosion, dust-proof and moisture-proof coating, protect stable performance, prevent short circuit, oxidation and corrosion. The consumption of the whole device is less than 50mA. Note: This version is compatible with a 7S 20 string battery pack. So cost effective, you just need to change the wiring method it will work. BMS compatible with battery pack:7S 8S 10S 12S 13S 14S 15S 16S 17S 18S 19S 20S Specifications.