REC Active BMS

We are proud to announce our new product REC Active BMS for 4 cells connected in series with active bi-directional balancing. Long-term development now enables us to present you this excellent device, proven with various real life test conditions, latest technology of electronics components and unbeatable balancing algorithms.



  • Li-PO, LiFePO4, LiFeYPO4, LiCoO2, LiMnNiCo and LiMnO4 Lithium-Ion chemistry
  • suitable for 4 in-series connected cells per unit
  • high efficiency 2 A bi-directional active balancing (pack to cell and cell to pack)
  • IP65 protection enclosure, AMP 35 pin water resistant connector
  • 2 – 5 V measuring range, 2 mV accuracy
  • up to 2 digital temperature sensors
  • shunt current measurement
  • robust and small design
  • galvanically isolated RS-485 and CAN communication protocol
  • two programmable fused relay output
  • two programmable fused digital output
  • ON/OFF switch
  • LED and buzzer status indication
  • equipped with bootloader for remote firmware update
  • error LED + buzzer indicator
  • PC user interface for changing settings, data-logging and firmware update
  • compatible with REC LCD touch display and Wi-Fi module for monitoring
  • compatible with Victron inverters for solar applications
  • compatible with Wakespeed regulators for marine applications


  • low power microcontroller RTC
  • custom made software with bootloader for remote firmware update
  • 60 mW self power consumption with disabled CAN and all outputs

RS - 485 Communication:

  • galvanically isolated RS-485 communication
  • Slave configuration
  • RS-485 driver primary side supply is activated with Master connection to save energy consumption
  • fully compatible with REC LCD touch display and Wi-Fi module for monitoring

Active Balancing:

  • 2A cell equalizing with active balancing with synchronous flyback bi-directional energy transfer: cell to pack and pack to cell
  • top side and bottom side balancing prolong the cycle duration due to the weakest cell


  • two fused relay outputs with NO and NC pins
  • two fused galvanically isolated/non-isolated digital outputs with PWM option

Galvanically Isolated CAN:

  • galvanically isolated CAN
  • 100, 125, 250, 500, 1 MHz bit-rate selection
  • message programming
  • disable option

Complete Wiring of ABMS Connector:

  • 5 cells wires (l = 1 m)
  • relays, digital output wires (l = 0.5 m)
  • RS485 cable (l = 0.5 m)
  • CAN cable (l = 0.5 m)
  • remote ON/OFF switch (l = 1 m)
  • temperature sensor (l = 1 m)
  • cable for current sensor shunt (l = 1 m)


  • width with mounting pads = 135 mm
  • width = 105 mm
  • length with connector = 111 mm
  • length = 104 mm
  • height = 44 mm
  • connector width = 59.5 mm
  • hole diameter = 4.5 mm
    We suggest M4 screws for mounting.

3D Step Model: