(under construction)

Description:

Previously, we developed electronics for an Off-Grid Systems 75Ah/105A LFP Battery system. Now we're going to make this a bit more modular so we can scale the battery management system to physically larger batteries like 560Ah/15KWh and 100kWh+ in the talks. The modularity will also enable higher voltage systems, for example 48V and 96V.

The essential building block of this battery system is our balancer/cell module. This module allows for a linear array of cells, each with own voltage measurement and multiple temperature sensors. This is complemented with a 10A active balancer and a PTC heater pass-through.

The BMS board is specific for this Off-Grid system and provides the split charge and discharge connections and the proprietary CAN-bus connection and protocol. Due to the semiconductor-based switching, it is only suitable for 24V packs.

A new feature for this battery system is the optional interconnected fire extinguisher module. This maintenance-free module has a 15 year lifespan (both aerosol and the backup battery). It's BMS connection allows for remote insight in status, voltages, temperature, serial numbers and expiration date.

Battery system circuit boards

Specifications:

  • Operating voltage 20-30VDC (nominal ~25.6V)
  • 105Ah or 280Ah LiFePO4 cells in 8S1P or 8S2P configurations
  • 200A Discharge and 100A charge paths, individual switchable, short-circuit proof
  • Balancer current up to ~10A
  • Independent charge and discharge shunt resistors for current measurement and charge accumulation
  • State of Charge operating region 10% to 95%
  • Statistics-based balancing and advanced OCV-based end/top balancing
  • Heater output for cold climate operation (charge < 0°C, discharge < -20°C)
  • Battery statistics for delivered energy, saved energy, cell voltages and charge cycles
  • Event logging via CAN-bus
  • CAN-based OGS control® bus connects up to 48 batteries with the OGS control® Master
  • Optional fire extinguisher system
  • Optional front panel graphic display

Batteries:

  • 28V 105Ah (~3kWh), modular hot plug'n'play, split charge/discharge, OGS CAN-bus
  • 28V 560Ah (~15kWh), modular hot plug'n'play, split charge/discharge, OGS CAN-bus
'OGS control' is a registered trademark of Reijneveld Machinebouw B.V.