FoxESS Community - Owners & Installers Forum

Hi All,

I have a new setup and just starting out.

I'd like to setup my inverter & battery to only 'operate' within 10% - 95% of its capacity (hopefully to maximize battery lifespan). My aim is the following:

1. Charge from solar panel until battery reach 95% and start grid export/consume
2. Not going below 10% when on battery -> Start pulling from grid at night time when battery level is at 10%

Under 'Quick settings' on the app, System Min SOC is already at 10% but when I tried to set the System Max SOC to 95% (from 100%) , I'm getting 'Write Failed' error.

Note that I haven't touch mode scheduler yet. Work mode is set to 'Self use', with nothing custom scheduled.

Going (physically) on the inverter itself, there is a 'Max SOC Battery on Grid' settings under Settings -> Battery that I can adjust (there is no 'Max SOC' option!) . Is this the same thing?

Am I completely going the wrong route to achieve this?

Thank you

I wouldn't recommend limiting it to 95%, the BMS inside does need to calibrate the end points to know how much power it has stored. I have used 10% & 100% for over a year, and have 100% SoH (State of Health) remaining.

There are some new firmwares being baked (depending on device) that should allow you to have better control over your scheduling, once these are ready, then you could limit charge rates better during the different seasons as needed.

Interested to see this. I've been wondering the same thing as the OP.
I did have maxSOC limited to 95% based on ideas read elsewhere, not personal expertise, that this should extend battery life, but having read on this forum that the BMS could be unhappy with this strategy I put it back to 100%.
My current strategy, based again on web search not expertise, is to run it at 95% routinely to try to protect battery, but let it go to 100% once a week or so to try to keep the BMS happy.
Any advice on the wisdom of this appreciated.

User Wyndstryke recommends 100% SoC at least weekly, and to reach 10% once a month to keep the BMS calibration fairly accurate.

I figured that as long as I don't abuse the battery cycles, or high/low heat extremes then it should be fine.

I normally leave it in self-use and never get anywhere near 10%. I guess I'll have to make an effort.