Service Repair Report: Deye (M5.3) Lithium Battery
Report Date: January 29, 2026
Equipment Model: Deye RW-M5. 3 PRO
Status: Repair Completed / Testing Passed
1. Damage Assessment & Diagnostics
The unit was submitted for repair following a severe electrical surge incident (lightning strike). Initial inspection and diagnostic testing revealed the following:
- Primary Point of Failure: The RJ45 communication ports (CAN/RS485/RS232) sustained direct high-voltage entry.
- BMS Status: The Battery Management System (BMS) was non-responsive. Not Switching on and no output The logic board failed to initiate the boot sequence, and the LED status indicators remained inactive.
- Cell Health Check: Manual voltage readings across the individual LiFePO4 cell banks confirmed that the internal chemistry and cell interconnects remained intact and balanced. The damage was isolated to the electronic control layer.
2. Work Performed
- Component Removal: The damaged BMS logic board and integrated RJ45 interface assembly were safely disconnected and removed from the chassis.
- BMS Replacement: A genuine Deye SE-G5.1 Pro Replacement BMS was installed.
- Wiring Audit: Inspected all internal temperature sensors (NTCs) and cell-tap wiring harnesses for insulation melting; no secondary damage was found