123\SmartBMS gen3

123\SmartBMS gen3 is an easy to use yet advanced, modular BMS to keep your lithium batteries in perfect condition, increasing the lifespan of the battery pack.

The BMS measures important data like cell voltages, cell temperatures and in- and outgoing currents with the two included high accuracy, dual range current sensors. By measuring both currents independently, it is possible to know the current production and consumption. The system balances all cells to the same voltage during charging.

Two integrated signal relays with potential free contacts can be used to switch enable/disable signals or power relays to control the power to chargers/solar regulators and/or inverters.

Easily connect your phone to the BMS to see relevant information including state of charge, energy consumed, energy stored, in- and outgoing current, cell voltages, cell temperatures, SoC history of the last week and error history.



  • LTO compatible, Operates on cell voltages between 1.5V and 5.0V
  • High accuracy, dual range current sensors to measure a wide range of currents up to 500A.
  • Accurate SoC using measured battery capacity
  • State-of-health measurement
  • Error history to see when, what cell and which error occurred.
  • SoC logging of the last week.
  • Lowest and highest battery voltage logging of the last week.
  • Direct on-cell voltage measurement.
  • Direct on-cell temperature measurement.
  • Over the air firmware update
  • Separate minimum temperature for charging and discharging
  • Easy configuration with expert mode for extra options

Main features

  • Modular BMS which can be used from 2 to 255 cells.
  • Advanced Victron GX integration and remote monitoring via Victron VRM (123\SmartBMS to USB cable required).
  • Can be mounted directly on the cells, no external controller needed.
  • Two signal relays with potential free contacts which indicate the system is allowed to load and/or charge. This can be used to switch enable/disable signals or power relays.
  • Possible to use two current sensors instead of one to see consumed and produced energy independently.
  • Bluetooth connection to see relevant data on your portable device.
  • Compatible with almost any cell chemistry including LTO, LiFePO4, NMC and NCA.
  • 1A balancing current. Even big cell capacities will be balanced.

Frequenty Asked Questions

For support and frequently asked questions, please see our dedicated Support.