Firmware and updates6 September 2026· Ľubomír Sokolík

How to correctly choose firmware for Pylontech US2000C, US3000C, and US5000

With Pylontech, firmware cannot be selected based on the serial number alone. For US2000C and US3000C, the entire ZIP file is used, and the authorized tool automatically selects the correct branch based on the BMS hardware. For US5000, it is more complicated and the documentation is contradictory on some points.

This article was machine-translated from the Czech original.

A common question with Pylontech batteries is: “Which BIN file should I upload to the BMS?” The answer is: for US2000C and US3000C, you shouldn't select it manually at all. The correct procedure is to use an authorized upgrade tool and let it decide based on the specific electronics inside the battery.

What the correct package for US2000C/US3000C looks like

For these models, the entire, unextracted package is used:

US2000_C3000C_C_V3.1&E2_2.5.zip

Do not load an individual BIN file into the tool, but this exact double ZIP. The Upgrade Tool V1.0.10_3 tool connects to the battery, reads Device Name and Board, and automatically selects the correct branch.

How the tool selects firmware automatically

The detected BMS hardware determines the firmware:

US2000C, typically C/ST1 branch → US_C_V3.1_Crc.bin
NF4.E2 / US2000C_NF4 → US_E2_V2.5_Crc.bin

So you should not manually select one of the BIN files in the tool based on the serial number. Select the entire ZIP file and let the tool decide based on the BMS hardware.

Why you cannot rely solely on serial numbers

For US5000, the manual mentions distinguishing based on the 8th and 9th character of the serial number. For example:

Y241106C50560355
       ^^
       C5

Counting from the left, the 8th character is C and the 9th character is 5, meaning the C5 branch. For C5, the manual lists the file:

US_E3_V2.3_Crc.bin

However, in the very same line, the document also states “V2.0”. Therefore, the document is contradictory, and I would not flash the file based on C5 alone without checking the board and getting confirmation from Pylontech/Effekta. On Forest, we have C5 batteries working with both V2.0 and V2.3.

Safe selection procedure

First, obtain the Device name, Board version, Soft/Main version, Boot version, and SN from the Console in read-only mode.
For US2000C/US3000C, insert the entire unextracted double ZIP into the authorized tool.
Let the tool select C V3.1 or E2 V2.5 based on the board.
Before actual programming, verify that the tool has recognized the correct model and board.
After the update, read info again to confirm the actual new version and normal telemetry.

Why you shouldn't select a ZIP via the PylonCheck dashboard yet

The current firmware uploader in the PylonCheck dashboard cannot perform this automatic detection. It does not parse the ZIP file and could send its raw bytes as firmware. Therefore, do not select a ZIP or firmware based solely on the serial number via the dashboard for now. Use an authorized tool from the manufacturer or distributor for firmware updates.

Conclusion

Correctly selecting firmware for Pylontech is not about reading the serial number, but about identifying the BMS hardware. For US2000C and US3000C, it is simple — you load the entire ZIP and the tool does the rest. For US5000, be cautious and, in case of ambiguity, do not flash the firmware until you verify the board and recommendations directly with Pylontech or Effekta.