FoxESS Community - Owners & Installers Forum

I have a 5kW Fox ESS inverter and at the moment I have two Fox ESS FE-HV-EQS-4800 batteries arranged in a master/slave configuration. Each provides 4.66kWh of storage.

I've done the maths regarding heating of an extension using electric radiators, and I need to add two more 4.66kWh batteries to the stack. The installation instructions suggest they are very modular so its a case of powering down, removing the master from the top, adding the two slave units, and putting the master back on the top and powering up again.

I am not going to do this myself, even though it appears to be simple - but have a qualified solar installer lined up.

To avoid any downstream issues, I am looking for guidance on how simple the job is to be done.

Is it as simple as the inverter and batteries will simply recognise the extra batteries and start to charge after installation or is the installer going to have to do some configuration on the system for FOX to be able to show them online on the App etc ? I dont know how 'smart' the system is and whether they kind of speak to each other automatically to update the system configuration between themselves?

I am just tring to undertand how simple it is and whether I will have issues downstream after the physical batteries are added to the stack ?

Many thanks for any advice.

Yes, it really is as simple as that - you must make sure your existing batteries are as close to 50% SoC as possible (within 1 few %) when you add the new batteries. As you say you need to remove the Master battery, add the 2 new batteries on top of the existing slave and then add the Master back on the top of the stack.

The Master will scan and auto address the batteries, you don’t have to do anything it will self populate and update in your app.

It’s very likely the new slave battery firmware will be a different version to what is installed so check the versions in your app and if different raise a support ticket for Fox to update the battery firmware.

Thank you - much appreciated