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Firmware Updates

 

Find your current firmware version

Before updating, check the version shown in the bottom left corner of PBMS Tools when connected to your battery.

PBMS Tools Screenshot

Important: Beta firmware enables increased battery utilization down to 5 percent for a total of 95 percent DOD. These builds are under testing and may not suit all users.

Beta firmware releases Testing

We are testing firmware that reduces the force charge threshold from 15 percent to 5 percent. This can expose around 10 percent more capacity on inverters that honor battery force charge commands. Sunsynk and Luxpower usually benefit most. Some inverters enforce a minimum threshold that cannot be overridden.

BMS model Battery model Firmware version Download
P16S100A-XXXX-1.0X Fogstar Energy Server Rack Gen 1 1.07C Download
P16S100A-XXXX-2.0X Fogstar Energy Server Rack Gen 2 2.04B Download
P16S200A-XXXX-1.0X Fogstar Energy 15.5kWh Gen 1 1.03B Download

Note: The update tool is included in each firmware zip.

Stable firmware releases

These are the latest stable updates. They supersede previous versions and include prior fixes and enhancements.

BMS model Battery model Firmware version Download
P16S100A-XXXX-1.0X Fogstar Energy Server Rack Gen 1 1.07 Download
P16S100A-XXXX-2.0X Fogstar Energy Server Rack Gen 2 2.04 Download
P16S200A-XXXX-1.0X Fogstar Energy 15.5kWh Gen 1 1.03 Download
P16S200A-XXXX-2.0X Fogstar Energy 16.1kWh Gen 1 2.00B Download


Changelog

22 Aug 2025 (P16S200A-XXXX-2.0X - Stable Firmware Release)

  • Usable capacity increased to 95 percent
  • Force charge threshold reduced from 20 percent to 5 percent

28 Sep 2024

  • Fixed Sunsynk issue where battery would not consistently reach 100 percent SOC
  • Raised charge current limit on 15.5kWh Gen 1 with Sunsynk from 95A to 195A
  • Corrected communication error affecting some Growatt models after their update

Previous

  • Lowered BMS measurement threshold to 300mA to prevent Solis induced sleep
  • Fixed Solis Pylon protocol Battname FAIL error
  • Improved SOC using EVE LF100A and EVE LF304 specific curves
  • SOC now accounts for BMS screen consumption

Firmware update guide

Important: Turn the battery breaker to OFF, then power the battery so the BMS is awake before you start the upgrade tool. Ensure PBMS Tools is fully closed during upgrade.

  1. Open the downloaded firmware zip
  2. Extract all files
  3. Open the BMS Upgrade V1.03 program, PBMS Tools must not be running
  4. Connect the RS232 cable to the battery port and to your computer USB
  5. Select the correct serial port in BMS Upgrade V1.03
  6. Enter password 541800
  7. Click Browse and select the extracted .bin firmware file
  8. Click Upgrade to begin
  9. When prompted, choose Yes to proceed

Do not disconnect the RS232 cable or power during the update. If the process fails, re-run the tool without cycling power first.

Important notes:

  • Verify that the PBMS Tools version shown in the bottom left matches the BMS model listed in the tables before flashing
  • Need help: customerservice@fogstar.co.uk