Easun Firmware Update May 2026

This report outlines the procedures, risks, and common issues associated with updating the firmware on EASUN solar inverters. EASUN inverters are often clones of Voltronic Power units, and as such, they use similar update tools like WatchPower. 1. Preparation Requirements

Before attempting an update, ensure you have the following hardware and software to avoid "bricking" the device:

Original Cables: Use the specific RJ45-to-Serial adapter cable that came with your inverter, as pin configurations vary by model.

RS232 to USB Adapter: Most modern laptops require this to bridge the serial cable to a USB port.

Stable Power: Ensure the inverter is connected to a stable battery source (preferably fully charged) and your laptop is plugged into power to prevent a shutdown during the process.

Correct Firmware: Firmware must match your specific model and current version prefix. Flashing an incompatible version (e.g., jumping from version 46.xx to 90.xx incorrectly) is a leading cause of permanent failure. 2. General Update Procedure

Updates typically involve two stages: updating the Main CPU and then the Remote Panel/Display CPU.

Identify Current Version: Use the inverter's LCD menu or the WatchPower app to note your current main CPU and remote panel versions.

Close Monitoring Software: Completely exit WatchPower or any other monitoring tools (including those in the system tray) to free up the COM port.

Run the Reflash Tool: Open the manufacturer-provided update tool (e.g., Reflash.exe), select the correct .hex or .inv file, and choose the correct COM port.

Monitor Progress: The inverter display will often go dark or show an "UP" status during the 5–15 minute process. Do not disconnect cables until a "Successful" message appears. 3. Known Risks & Issues Issue Description Bricked Inverters

Users have reported total device failure after receiving the wrong firmware files directly from EASUN support. Backfeeding/Mixing Bugs

Some updates (e.g., version 6.67 for SMX-II) introduced issues where the inverter incorrectly backfeeds current to the grid or causes electrical buzzing. Lost Features

Newer firmware versions sometimes remove previously available functions, such as specific grid-discharge timing settings. MPPT Improvements easun firmware update

Community-modified "Beta" firmwares are popular for fixing MPPT "stuck" issues, though these are unofficial and carry higher risk. 4. Obtaining Firmware

EASUN does not maintain a public, centralized firmware repository. You can obtain files through:

Direct Request: Contact the EASUN Official Store Help Center with your model number and a photo of your device's nameplate.

Official Downloads: Some software and manuals are hosted on the EASUN Download Page.

Third-Party Communities: Forums like DIY Solar Power Forum and Power Forum are often the only source for older "factory" versions needed for downgrading.

⚠️ 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.

Phase B: The Remote Panel (U2) Update

  1. Disconnect power to the inverter (turn off battery, wait 30 seconds).
  2. Reconnect battery. The screen will show the old U2 version.
  3. Some models require a different flasher for the screen (usually "RemotePanel.exe").
  4. Repeat the connection process, but load the Panel_*.bin file.
  5. The screen will go blank. When it reboots, it should show the new U2 version.

Step 1: Identify Your Exact Model & Current Firmware

Check the sticker on the side or the LCD info screen:

  • Model: e.g., Easun iSolar-SMX-II-5.6kW, REVO II 5.5kW, PowerPlus 3.2kW
  • Main CPU U1 version (shown on LCD startup or in setting menu)
  • Secondary CPU U2 version (if applicable)

Example: U1 = 12.21, U2 = 12.11

Do not mix firmware between different hardware revisions (e.g., 5.6kW vs 3.2kW, 48V vs 24V).

Step 3: Decode the Hardware Library

Open the inverter’s physical side panel (with power OFF and capacitors discharged). Look for a sticker on the main control board reading something like MB V3.2 or EASUN 5KVA DSP REV A.

Pro Tip: Easun re-brands OEM hardware from companies like PowMr, Voltronic, and SRNE. Your "Easun" firmware might actually be an Axpert King or MKS firmware. Cross-reference your U1 number online.

📌 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. This report outlines the procedures, risks, and common

For Easun solar inverters, firmware updates are generally handled through official support channels rather than public download repositories. While manufacturers like Easun Power emphasize that updates can resolve communication failures and enhance cybersecurity, updating is considered high-risk for these specific devices. Official Sources and Technical Guides

Direct Support Requests: Easun does not typically host a firmware download page. Users often must contact Easun Support directly with their serial number and current firmware version to receive the correct update file.

Troubleshooting Guide: The Easun Solar Inverter Troubleshooting Guide provides official advice on when a firmware upgrade might be necessary, such as for persistent communication errors with monitoring equipment. Expert Community Advice & Patched Firmware

Because Easun often uses hardware clones (like Voltronic or SRNE), community forums are the primary source for specific firmware files and "patched" versions that fix common bugs.

DIY Solar Power Forum: This community is a major hub for discussing specific firmware versions (e.g., SMG II 11kW or ) and recovering bricked units.

Power Forum Patched Firmware: Expert users like "Coulomb" provide patched firmware versions to address issues like MPPT "stuck" voltages at low levels, which official updates may not fix. Critical Risks to Consider

What is Easun Firmware Update?

Easun is a brand that specializes in solar charge controllers, inverters, and other renewable energy products. A firmware update is a software update that is used to improve or modify the functionality of these devices.

Why is a Firmware Update Needed?

Firmware updates are released to fix bugs, add new features, or improve the performance of Easun devices. These updates can:

  1. Improve device stability and reliability: Firmware updates often address issues that can cause devices to malfunction or fail.
  2. Add new features: Updates can introduce new features or enhance existing ones, making the device more efficient or user-friendly.
  3. Enhance security: Firmware updates can patch security vulnerabilities, protecting devices from hacking or unauthorized access.
  4. Improve compatibility: Updates can ensure that Easun devices work seamlessly with other devices or systems.

How to Update Easun Firmware

The process of updating Easun firmware may vary depending on the specific device and the type of update. Here are general steps:

  1. Check for updates: Visit the Easun website or contact their support team to see if a firmware update is available for your device.
  2. Download the update: If an update is available, download the firmware file from the Easun website or through their support team.
  3. Connect to the device: Use a computer or mobile device to connect to the Easun device, usually through a USB cable or wirelessly.
  4. Follow update instructions: Follow the on-screen instructions to upload the firmware update to the device.

Precautions

Before updating the firmware:

  1. Backup device settings: Save your device settings to prevent losing them during the update process.
  2. Use a stable power source: Ensure the device is connected to a stable power source to prevent interruptions during the update.
  3. Follow instructions carefully: Carefully follow the update instructions to avoid any errors or damage to the device.

If you're looking for specific information on updating your Easun device, please provide more details about your device and the update you're trying to perform. I'll do my best to guide you through the process.

Updating your Easun solar inverter's firmware can resolve critical bugs, improve Maximum Power Point Tracking (MPPT) efficiency, and ensure compatibility for parallel unit configurations. Prerequisites for a Successful Update Before beginning, ensure you have the following components:

A Windows PC/Laptop: Most official update tools like Watchpower or SolarPower are designed for Windows.

Correct Communication Cable: Depending on your model, you will need either a USB-to-RS232 cable or a direct USB (Type-B) cable.

Stable Power Source: The inverter should be powered by a battery. It is highly recommended to disconnect PV (Solar) and AC Load to prevent power fluctuations during the process. Where to Find Easun Firmware Files

Finding the exact firmware can be challenging as it varies by specific hardware versions.

Official Help Center: Easun provides manuals and some software links on their official help center.

Specific Model Portals: Some firmware for popular models like the SMX-II or SMG series can be found on cloud repositories linked by Easun support.

Direct Support: If your specific model is not listed, you should email Easun support with your Order Number, Machine Model, and a Description of the Problem (e.g., Error 42 or fan noise issues). Step-by-Step Update Procedure Easun firmware 2.xx | DIY Solar Power Forum

Updating EAsun inverter firmware can resolve bugs but risks permanently damaging ("bricking") the device if mismatched versions are applied [3, 11, 16]. It is critical to match the new firmware version to the current unit's specific model, hardware revision, and battery configuration, rather than updating based on "latest" status alone [3, 4, 11, 13]. For the full report, visit the DIY Solar Power Forum DIY Solar Power Forum or Power Forum South Africa Power Forum South Africa

Step 2: Install Drivers & Software

  1. Install USB-to-RS232 drivers (if using an adapter). Download from the adapter chip manufacturer (Prolific, FTDI, CH340). Do not rely on Windows auto-install.
  2. Download the update tool. EASUN typically uses "Remoting UpdateTool.exe" or "Wizard" . This is often included in the firmware ZIP file you received.
  3. Check COM Port:
    • Open Windows Device Manager > Ports (COM & LPT) .
    • Note the COM port number (e.g., COM3, COM5). If it's above COM9, change it to COM3-COM9 in port settings.

Step 1: Physical Connection

  1. Power down the inverter completely.
    • Turn off AC input (mains/grid).
    • Turn off AC output (loads).
    • Turn off PV (solar) disconnect switch.
    • Remove the battery fuse or turn off the battery breaker.
    • Wait 2 minutes for internal capacitors to drain.
  2. Connect the programming cable.
    • Locate the RS232 or USB-B port on the inverter (usually next to the battery terminals or the LCD panel).
    • Plug in your cable.
    • Connect the other end to your Windows PC.
  3. Re-connect battery power only. (Do not turn on PV or Grid yet). The inverter should power on in standby mode.

Step 2: Get the Correct Firmware & Tools

  • Contact Easun support (sales@easunpower.com or via Alibaba) – give them model + current U1/U2 version.
  • Check forums – DIY Solar Power Forum, AEVA, or YouTube channels (e.g., Off-Grid Garage, SolarPower). Many users share official files.
  • Avoid random file sites – high risk of malware or wrong version.

You’ll need:

  • Firmware file (usually .hex, .bin, or .dsp)
  • Flashing software – often WatchPower (Easun’s PC tool) or USB-ISP for certain DSPs
  • Windows PC (most tools are Windows-only)
  • USB-to-RS232 cable (driver: Prolific PL2303 or FTDI)

2. The DIY Solar Power Forum (Best Resource)

The forum at diysolarforum.com has a dedicated "Voltronic / Axpert / Easun" section. Search for your exact model. Users share "refurbished" firmware packs. Phase B: The Remote Panel (U2) Update