Battery Management System
New Thunderstruck Motors Battery Management System by Dilithium Design
Shown with one BMS Measurement Board and one Satellite, harness and harness tester
The Dilithium Design Battery Management System is a modular BMS designed for Electric Vehicle applications. The BMS is implemented as two assemblies. The BMS Controller (BMSC), consists of the BMS Processor and a measurement board in a single enclosure. The BMS Satellite (BMSS) contains a BMS measurement board. The BMS Controller is a standalone 24 cell BMS, and up to three BMS Satellites may be added, resulting in 48, 72, and 96 cell systems. Multiple systems may be used together to monitor larger packs.
The BMS measurement board has been optimized for monitoring cells in large lithium packs and was designed to minimize power consumption, especially during long-term storage where battery drain is unacceptable.
The BMS diagnostics verify proper functioning of measurement circuitry, verify cell wiring, and monitor for communication errors. In operation, all cells in the system are measured approximately 8 times a second with high coherency and accuracy.
When driving, the BMS monitors the pack and collects pack and cell statistics. Statistics include high and low cell watermark data which can be used to track cell performance under load, and Standard Deviation, which measures pack balance.
The BMS supports several error conditions (or “alerts”). When driving, an alert is generated if any cell drops below the configurable Low Voltage Cutoff (LVC) threshold. When charging, the BMS will generate an alert if any cell rises above the High Voltage Cutoff (HVC) threshold which can be used to stop charging. The BMS supports a configurable Balance Voltage Cutoff (BVC) threshold, which can be used to communicate with the charger to reduce charge current.
The BMS supports smart cell balancing. A cell is balanced if its voltage is greater than the average cell voltage for the pack and if its voltage is greater than a configurable minimum threshold (set by BVMIN). Cell balancing occurs when driving and charging, and not just at the very end of a charge cycle.