Easun Firmware Update ((install)) -

Feature Draft: EASUN Firmware Update

6. New Features / Improvements via Firmware Update (examples)

Better MPPT tracking (e.g., wider panel voltage range)
Battery communication protocols – added Pylontech, Dyness, Weco, or CAN/RS485 fixes
LCD display enhancements – show individual battery voltage, daily yield
Fan speed logic improvement – quieter operation under low load
Parallel operation stability – reduced circulating current
Modbus register additions – for advanced monitoring (Home Assistant, Grafana)

Phase C: Restoring Defaults

After a successful Easun firmware update, the EEPROM data is misaligned.

Go to Setting 05 (Battery type). Change it to User (USE).
Go to Setting 19 (Bulk voltage). Set to 56.4V.
Go to Setting 20 (Float voltage). Set to 54.0V.
Save and reboot. Do not use "Factory Reset"—it loads the old calibration.

📌 Final Advice

If you’re not comfortable with RS232, bootloaders, and Windows drivers – don’t do it. Pay a technician or leave it.
Record original firmware version before updating – you may need to downgrade.
Easun often rebrands Voltronic Power inverters – firmware from Axpert King/VM may work but only if hardware is identical (research first).

Useful resources:

Easun official website – support section
DIY Solar Power Forum – search “Easun firmware update”
YouTube: “Easun inverter firmware update” (watch 2–3 videos for your exact model)

If you get stuck, reply with your exact model number and current U1/U2 – I can try to help locate the right file. easun firmware update

⚠️ Critical Warning: A failed firmware update can brick your inverter (make it unusable). Do not interrupt power or disconnect the USB/RS232 cable during the process.

Part 9: Alternatives to Official Firmware – The "Cross-Flash" Risk

Because Easun hardware is usually a clone of Voltronic (Axpert), many users successfully flash original Axpert firmware onto their Easun units. Feature Draft: EASUN Firmware Update 6

The Risk: You gain features (like Pylontech CAN bus V2.0), but you lose Easun-specific fan curves. The Benefit: Axpert firmware is updated quarterly. Easun firmware might be years old.

How to do it safely:

Verify your internal board says Axpert MKS III Compatible.
Download Axpert_Reflash_V90.06 from a trusted source.
Use the USB to TTL method (3.3V logic), not RS232.
Do not update the secondary CPU (U2)—that is screen-specific. Only flash the DSP.

If the cross-flash fails, you cannot blame Easun support.