1. BMS1202 Introduction

Introducing the LiBat™ BMS1202, a compact battery management system slave module designed for seamless integration into 5S-12S battery configurations. This fully digital, ready-to-use module operates exclusively as part of a larger system, communicating with the master module through a dedicated isolated differential communication line. Controlled by the master module, the BMS1202 ensures precise coordination within the battery management system. Remarkably versatile, these slave modules can be stacked up to 16 units via a robust communication line, depending on the master (see User Manual 3.1 Battery Topology), allowing for extensive scalability. Furthermore, the daisy-chainable design allows the modules to be placed with CAT5e or CAT6 cables up to 50 meters long, offering flexibility in system configuration and placement.

Key Features:

  • Board size 90mm x 60mm
  • Compact, plug-and-play BMS slave module
  • 5S-12S cell measurement with 0.1mV resolution
  • Adjustable passive balancing current
  • Auto deep sleep
  • 1 kV isolated daisy-chain communication line on 2x RJ45 and 2x 4-pin connectors
  • Module ID set by a 4-bit ADDRESS switch, line termination switch on the board
  • Self powered
  • 3 external, 1 internal NTC
LiBat™ BMS1202 v2.0 board, top right view
Fig.1.1: BMS1202, Top Look
LiBat™ BMS1202 v2.0 board, bottom left view
Fig.1.2: BMS1202, Bottom Look

Table.1.1: BMS1202 Technical Specifications

PARAMETER SPECIFICATIONS
Power Source Self powered. No external power need.
Power Consumption Power Down: ~0.050 mW , RUN State: ~300mW
Wake Up Trigger Master Communication Start
LED Run (module awake)
Digital Interface 1 x Isolated Daisy-Chain, 1 kV isolation (2x RJ45, 2x 4-pin connector)
Daisy-Chain Cable CAT5e or CAT6, up to 50 m
Number of cells 5 to 12 cells, at least 11 V in total
Cell Type Any battery cell in voltage range
Minimum cell voltage 250 mV
Maximum cell voltage 4500 mV
Accuracy of Cell Voltage Measurement ±1.6mV typical, < ±8.3mV max
Balance Method Passive Balancing
Balance Current 420mA @ 4.2Vdc cell voltage
Balance Power 2W max. per cell
Temperature Sensor Type NTC, 10KΩ @ 25 °C
Temperature Sensor Accuracy ±1.5 °C (depends on sensor sensitivity)
Number of Temperature Sensor Up to 3 external sensor probes, 1 x On board NTC
Operating Temperature -20 °C to +70 °C (-4° F to +158° F)
Relative Humidity 5% to 95% (non-condensing)
Dimensions and Weight 90 mm X 60 mm X 17.8 mm, 50g