Easun Firmware Update Fixed -

This guide outlines the standard procedure for updating the firmware on EASUN POWER solar inverters. Firmware updates can resolve software bugs, improve battery compatibility (especially for LiFePO4), and optimize charging logic. ⚠️ Critical Pre-checks Identify Your Model

: Firmware is specific to the hardware version (e.g., SMG II, ISolar SMX, IGrid). Installing the wrong firmware can permanently brick your inverter. Check Current Version

: Navigate to the LCD menu (usually the last few screens) to note your current U1 (Main CPU) and U2 (Secondary CPU) versions. Stable Power

: Ensure the inverter is connected to a stable battery bank or utility power.

update using only solar (PV) power, as a passing cloud could cut power and fail the update. Phase 1: Preparation Request Firmware

: Contact EASUN support or your official seller with a photo of your inverter's side sticker (showing the serial number and model) to receive the correct Hardware Needed A Windows laptop.

The manufacturer-provided RS232-to-USB cable (or a specialized RJ45-to-USB cable depending on the port). Software Tools : You will typically need the ReflashTool InverterCheck utility provided by EASUN. Phase 2: Connection Connect the laptop to the inverter's Communication Port (RS232/USB). Device Manager

on your PC to identify the assigned COM Port number (e.g., COM3). Turn the inverter's power switch to

(the screen may stay on if batteries are connected, but the inverter should not be actively "working"). Phase 3: The Update Process Run the Tool : Open the update software (e.g., ReflashTool.exe : Select the correct

and set the Baud rate (usually 9600 or 19200, as specified in the update instructions).

: Click "Open" or "Browse" and select the firmware file provided by support. The inverter LCD will typically show "UP" or flash symbols. Do not disconnect the cable or power off the PC until the software shows "Update Successful."

: Once finished, disconnect the cable, turn the inverter switch to OFF for 30 seconds, then back to ON to initialize the new software. Troubleshooting Communication Failed

: Check that your USB-to-Serial drivers (usually CH340 or Prolific) are installed correctly in Windows. Wrong File Error

: If the tool rejects the file, do not force it. Verify the model version with the seller again. Stuck at 0%

: Try a different USB port or a shorter cable. Ensure no other monitoring software (like SolarPower or WatchPower) is running in the background. Do you have a specific EASUN model number particular issue you're trying to fix with this update?

Comprehensive Technical Brief: EASUN Inverter Firmware Updates

Updating the firmware on an EASUN inverter is a critical maintenance task used to resolve bugs, such as continuous fan operation or sensor inaccuracies, and to enable features like parallel system compatibility. Because many EASUN units are based on Voltronic Power architectures, they often share update procedures with brands like Axpert or MPP Solar. 1. Pre-Update Requirements easun firmware update

Before beginning, ensure you have the following hardware and environmental conditions to avoid "bricking" the device: Original Communication Cable:

Use the serial-to-Ethernet (RJ45) cable provided with your unit, as pin configurations vary by model. RS232 to USB Adapter:

Since most modern laptops lack serial ports, a reliable adapter is necessary. Stable Power Supply: The inverter be connected to a fully charged battery. Disconnect PV (solar) and AC input

to ensure the unit runs solely on battery power during the flash. Software Identification: WatchPower App

to verify your current main CPU and remote panel CPU versions. 2. Sourcing Firmware and Tools

EASUN does not always provide public download links for all models. You must typically match your model to specific monitoring software: Official Support: Contact the EASUN POWER Official Store

with your order number and model to receive the correct firmware package. Software Hubs: WatchPower/SolarPower: Used for SPR, SMR-II, and VE-II series. Voltronic FTP: Often hosts firmware for SMV, SMW, and SV-II series. Manuals & Drivers: EASUN Energy Download Center for general documentation. 3. Step-by-Step Update Procedure Prepare Connection:

Plug the RJ45 end of your cable into the inverter's computer port and the USB end into your laptop. Identify COM Port:

Open Device Manager on your PC to find the assigned COM port ID. Close Background Apps:

Completely exit WatchPower or any monitoring software from the system tray to free the COM port. Launch Reflash Tool: Open the manufacturer-provided update executable (often a file within a zipped folder). Load Firmware: Select the appropriate update file (typically ending in or similar). Initiate Flash:

Confirm the COM port and start the update. The process usually takes 5 to 15 minutes Post-Update Reset:

Once the "Successful" message appears, power down the inverter for several minutes, then restart it to clear the bootloader and finalize the update. 4. Safety Warnings and Troubleshooting

Updating the firmware on your Easun inverter is a critical maintenance task that can improve system stability, fix known bugs, and sometimes unlock new charging parameters. However, because it involves modifying the core operating software of your power system, it must be approached with precision to avoid "bricking" the unit. 🛠️ Preparation Checklist

Before starting, ensure you have the necessary hardware and environment: Correct Firmware File: Must match your specific model (e.g., ISolar SMG II

, or iGrid). Using the wrong file will disable the inverter. Communication Cable: Usually an RJ45-to-RS232 or a USB-to-RS232 cable. Windows Laptop:

Most Easun update tools (like "Reflash Tool") are Windows-based. Stable Power: This guide outlines the standard procedure for updating

Ensure the inverter is connected to a stable battery bank. Never update on PV power alone. 📝 Step-by-Step Update Process Connect the Hardware:

Plug the communication cable into the inverter's "COM" or "RS232" port and your laptop. Identify the COM Port: Device Manager

on Windows to see which port (e.g., COM3) the cable is using. Run the Update Tool:

Open the Easun Reflash/ISP tool. Select the correct COM port and set the Baud rate (usually 9600 or 19200). Load the File: Select the firmware file provided by Easun support. Initiate Flash:

Click 'Update' or 'Start'. The inverter fans may spin at high speed, and the screen might go blank or show "UPDT." Verify Success:

Once the tool shows "Update Successful," the inverter will reboot. Check the "U1" (Main CPU) and "U2" (Secondary CPU) versions in the settings menu. ⚠️ Critical Safety Warnings Don't Disconnect:

Pulling the cable during the "Erase" or "Write" phase will break the machine. Version Matching:

Always verify your current firmware version first. If your inverter has a circular screen versus a rectangular one, the firmware is often incompatible. Support First: It is highly recommended to email Easun official support

with a photo of your inverter's side sticker to get the exact file meant for your serial number. 🔍 Troubleshooting Common Issues Communication Error:

Check if the serial-to-USB driver is installed (often the CH340 or CP210x driver). Update Refused:

Ensure the inverter is in "Standby" mode (AC output turned off via the physical switch) but still powered by the battery.

If you are looking for a specific version, I can help you find the right contact or documentation if you tell me: What is your exact model name ISolar-SMG-II-5.6KP are you trying to fix with an update? Do you have the original communication cable that came in the box? AI responses may include mistakes. Learn more

Conclusion: Is an Easun Firmware Update Worth It?

Yes—if you are methodical, technical, and patient. For the average homeowner who just wants lights to turn on during a blackout, do not touch the firmware. For the solar enthusiast squeezing every drop of efficiency from a budget system, the Easun firmware update is the key to unlocking stalled potential.

Remember the golden rules:

Do not update during a thunderstorm (risk of grid surge).
Use an FTDI cable, not a $2 eBay special.
Back up your original firmware if possible (using a universal reader).
Prepare for recovery before you start the flash.

If you follow this guide, you will turn your off-the-shelf Easun inverter into a reliable, high-performance power station. If you skip the steps, you will own an expensive paperweight. The choice, and the soldering iron, is yours.

FAQ: Easun Firmware Update

Q: How often does Easun release firmware updates? A: Rarely. Maybe once every 18 months. Most updates are community-driven reverse engineering.

Q: Can I update via Bluetooth? A: No. The Bluetooth dongle is for monitoring only. It cannot send a bootloader payload.

Q: My neighbor bricked his unit. Can a repair shop fix it? A: Yes, if the shop has a JTAG programmer and can source the original EEPROM dump. Cost usually exceeds the value of the inverter ($100-$200). Buy a new control board instead.

Q: Does the update reset my BMS communications? A: Yes. You must re-pair the inverter with your battery BMS (reset DIP switches or redo Pylontech handshake).

Final Verdict: Proceed with caution, but proceed. A successful flash transforms your Easun from a budget compromise into a competitive powerhouse.

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

Step 3: Physical Connection

Power off inverter – disconnect PV, battery, and AC output.
Wait 5 minutes for capacitors to discharge.
Connect RS232 cable to RS232 port on inverter (9-pin D-sub, usually labeled "RS232" or "COM").
Connect USB end to PC.
Do not power on inverter yet (some models need standby power from battery – check your manual).

Some models (REVO series) require opening the unit to access a 4-pin programming header – do not attempt unless experienced.

4.1 Local Update (USB / RS232 – recommended for reliability)

Step-by-step workflow:

Download firmware – Get the correct .hex or .bin file from EASUN official support site (match exact model and hardware version).
Install EASUN Update Tool on PC.
Connect inverter to PC via USB/RS232 cable.
Launch tool – Select correct COM port and baud rate (default: 2400 or 9600 depending on model).
Load firmware file – Verify checksum (tool auto-checks).
Start update – Click "Update". Do not interrupt power or disconnect cable.
Wait for completion – Progress bar reaches 100%, inverter auto-reboots (≈ 2–5 minutes).
Verify version – Check new firmware version on inverter LCD or monitoring app.

⚠️ Before You Start: Critical Warnings

Do not update unless you have a specific issue – If your inverter works fine, leave it. Updates fix specific bugs, not add features.
Power stability is essential – A power failure during update can brick the inverter (needs mainboard replacement).
Only use firmware from Easun official source – Wrong file = dead inverter.
RS232/USB adapter needed – Most Easun inverters require a USB-to-RS232 (DB9) cable. Some newer models use USB-B (printer cable) or USB-to-TTL.