LIFEPO4 Smart BMS 4S , RS485 and Bluetooth can NOT be used at the same time !!!! Power display board，CAN is not working for LIfePO4 4S SMART BMS !! 300A~500A BMS can be delivered by one of international express（DHL,FEDEX,UPS） Advantages: 1. BMS was be manufactured by high quality Mos and IC imported . Keep your battery long cycle service life time. 2. Use top quality (A-level) protective integrated circuit IC, from the solution of Japan. 3. Extreme low power consumption. The consumption of the whole device is less than 50uA. 4. PCB use high anti-corrosion, high water resistance, high impedance ESD conformal Coating