Questions about grounding, grid charging, firmware

Instead of sending a support request directly to them, I’m posting here in hopes of sharing information. I currently have a single EP500 unit.

  1. How is the grounding terminal used (the one on the back near the switch)? Would it solve any grounding issues that currently require a bonding plug? If I were to use it, what gauge wire is required?

  2. Is there any incoming surge protection when connected to the grid?

  3. I see there are some firmware updates, is there a changelog available somewhere?


The grounding plug likely is connected to the chassis of the unit, and it is meant to connect it to a true ground. That way, if there is a fault and the chassis gets voltage, it will be shorted to ground, causing high current and trip some safety switch to shut things off, before you touch the charged box and get a shock. This is what I believe and usually happens, but I am not 100% sure for this unit.

This would not solve issues for appliance requiring a grounded plug (eg tesla mobile charger). In that situation the device is testing to see if neutral is shorted to ground. To solve that, you will need to wire a plug such that neutral and ground is connected together, preferably close to the power source.


Hi ed209,

Thank you for contacting us.
EP500 does not need to use the grounding terminal.
Please check and update the firmware in the app.

1 Like

I just updated my firmware.

FYI I had to temporarily adjust my max charge % to less than current %, to trigger battery discharge again while plugged into AC.

I use the Time Control UPS mode.

Hi! I am looking for the current firmware version level on my EP500.

  • Can you tell me where can I find it on the unit?
  • I think my unit was in the middle of firmware update sometimes ago.
    Can I get the latest firmware update again on my EP500?

Thank you in advance!

On the device, Data > Product Info

On the app, Settings (gear icon) > Firmware Upgrade