Relay: E-Mech Contactor 500A Ctrl-V 12-24VDC Vol-Rtg 12-900DC for BMS (#4814)

Features:

• Designed to be smallest, lightest weight, lowest cost sealed contactor in the industry with current rating 500A carry , 2000A interrupt at 320V
• Built-in coil economizer - only 1.7W hold power at 12V DC and it limits back EMF to 0 V.
• Operate at 12V min. - 24V
• Normal open
• Hermetically sealed - intrinsically safe, operates in explosive/harsh environmental with on oxidation or contamination of coils or contacts, including longperiods of non-operation.
• CE marketed for EV application
• Weight: 0.95lb (430g)
• AIAG GS9000 designed, built and approved.
• Please click here for data sheet: EV200AAANA

Q&A:
Q: When I use LiFePO4 Prismatic 20Ah, 40Ah, 60Ah, 100Ah, 200Ah battery modules with BMS system and solar charger controller, why should I need two relays, one on charge side, one on discharge side ?
A: If you eliminate charging relay, the system can work, but it will not have charging protection function for the battery, such as over voltage (cell voltage), over current , over temperature, external short circuit, ect..  The solar charger controller can only regulate input voltage and input current.

For the same, on the discharge side, the relay will be open if the cells is over discharged (Low voltage), Over current, over temperature ect..