REC BMS Master & Multiple Slave System | Parallel-Series Large Battery Systems

The 9M BMS Master unit monitors and controls up to fifteen REC Q BMS 16S units configured as slaves for cell strings up to 240 cells, or multiple series and parallel banks of up to 240 cells.  The manual can be downloaded here:   REC MANUAL FOR MASTER SLAVE CONFIGURATION.  Please contact Solar 4 RVs for more information and advice. 

The Battery management system (BMS) is a device that monitors and controls each cell in the battery pack by measuring its parameters. The capacity of the battery pack differs from one battery cell to another and this increases with number of charging/discharging cycles. Due to the different capacity this voltage is not reached at the same time for all cells in the stack. The lower the capacity the sooner this voltage is reached. When charging series connected batteries with single charger, the voltage on some cells might be higher than maximum allowed charging voltage at the end of charging. Overcharging the cell additionally lowers its capacity and number of charging cycles. The BMS equalizes cells’ voltage by diverting some of the charging current from higher voltage cells – passive balancing. The device temperature is measured to protect the circuit from over-heating due to the passive balancing. Battery pack temperature is monitored by Dallas DS18B20 digital temperature sensor/s. Maximum 3 sensors per Slave unit may be used.

• Li-PO, LiFePO4, LiFeYPO4, LiCoO2, LiMnNiCo and LiMnO4 Lithium-Ion chemistry
• Master + max 15 Slave combination (max 240 cells)
• compatible with all REC BMS units
• single cell voltage measurement (0.1 - 5.0 V, resolution 1 mV)
• single cell internal resistance measurement
• single cell under/over voltage protection
• SOC and SOH calculation
• over temperature protection (up to 3 temperature sensors per Slave unit)
• under temperature charging protection
• passive cell balancing up to 1.3 A per cell with LED indication
• shunt current measurement (resolution 10 mA @ +/- 300 A)
• 3 galvanically isolated user defined multi-purpose inputs/outputs
• 4 programmable relays (normally open and normally closed option)
• 12 V galvanically isolated supply (10.5 – 15 V)
• galvanically isolated RS-485 and CAN communication protocol
• error LED + buzzer indicator
• internal battery powered real time-clock (RTC)
• PC user interface for changing the settings and data-logging (optional accessory)
• WI-FI unit for wireless changing the settings and data-logging (optional accessory)
• LCD touch display for monitoring (optional accessory)
• hibernate switch

1 year warranty.