FoxESS Community - Owners & Installers Forum

Hi,

I have only recently (3 days ago!) installed solar panels and FoxESS EP11 battery and H1 Hybrid Inverter and am gradually coming to terms with its usage.

I am unfamiliar with System Minimum SoC and Battery Reserve Capacity (and certainly not the detailed technical details that go with them) but I understand the basics and I am a little concerned that much of what I have read elsewhere implies that Min SoC should be at around 20% (for ensuring good battery life) and this seems to go hand in hand with reserve capacity. Indeed, the pre-set levels for both on the Fox app were set at 20%. However, reading several of your associated replies on this forum re SoC, you recommend 10%. This is preferable for someone (like me) wanting to use as much battery resource as possible rather than the grid, but conflicts with general advice - and the Fox app!

Which is most appropriate please, and why?

Thanks

MinSoc is the system minimum state of charge the batteries can go to before they will maintain themselves (by cycling an occasional low power charge).

Battery Reserve (aka minsoc on grid) is the reserve setting if you have EPS fitted - this is where you have dedicated wiring that will be powered in the event of failure of the grid - the wiring and configuration is a relatively complex subject so easiest to say if you don’t have it then it should always be set the same as minSoC. If you do have it the difference between this and minSoC is the reserve power you want to hold back in case of grid failure.

With that said you should almost always set minSoC to 10%, they are warrantied to be used to this and as you’ve paid for 90% DoD you should definitely use it.
You said you have EP11, are they ‘warm’ i.e. they have the heater fitted as the only exception I would make to the 10% is if they are located externally and they don’t have heaters it is best to set it to 15% during a very cold spell. This is because the batteries essentially won’t charge below 0C and the extra few % helps maintain the battery life until the temperature increases enough to allow charge.

Many thanks Dave.

That clears it up for me. And though I have a EP11 it is located in a garage not on an exterior wall so i am content to go to the 10% setting.

Thanks again.