3S 18650 BMS Li-ion Battery Protection Enhanced Module 60A 12.6V Charger Board

Model: BMS-60A-3S. Note 2: Strictly follow the wiring of the diagram 0V, 4.2V, 8.4V, 12.6V, do not intentionally short circuit. The closer the capacity/internal resistance of the 3 batteries is, the better!

eBay