4S 120A 3.7V Lithium Iron Battery Protection Board – BMS With Balancing, Heat Sink & NTC Sensor

About This Product

This 4S 120A BMS is made for lithium iron phosphate batteries and packs a ton of protection into one small board.

It handles dynamic balancing at 3.

7V, with a standby current of just 25uA—so it barely sips power when idle.

Overcurrent protection trips at 150A for 2 seconds, and you can reset it by disconnecting the load or charging.
The balancing kicks in when cells get 30mV out of whack, and it cycles every 10 seconds to keep things even.

Heat's not an issue either—built-in heat sink with fins plus an optional thermal silicone pad (sold separately) can boost conductivity by 30%.

It's also coated with three-proof varnish, so it holds up fine in damp or dusty shops.

You get 8 layers of protection: overcharge, over-discharge, overcurrent, short circuit (500A trip), temperature (high at 65°C, low at -20°C), moisture, balancing, and more.

The NTC line monitors temps in real time, and the 100mA passive balancing helps your battery pack last longer.

Perfect for EV conversions, solar storage, emergency power, or car audio systems—this board keeps your batteries safe and sound.