FoxESS Community - Owners & Installers Forum

Anyone know why this might be happening - is a problem with the sensors or measurement ? appreciate any thoughts

kR

J

Is that just a single time, or past few days like that?

The pink above 0kW line does show normal stepping down of charge rate towards the end of cycle, just as you say it jumps up rapidly in terms of SoC.

Do you ever discharge to 10% and hold for a few hours and back to 100% for a few hours to calibrate the BMS?

It’s been doing it for the last two days out of four and I almost always discharge to 10% but my inverter at 6kw is not big enough to fully charge the battery 4xep12 in 6 hours hence not believing the 100%

My very quick maths puts you at needing 7kW for 6hrs to get from 10% to 100%.

All I can recommend is you look for an upcoming good solar day, discharge battery as late as you can to 10% and hold for 2-3hrs, then charge it up 100% and try and keep it held there by running in Self-use mode for when the Sun comes up. After a 2-3hrs at 100% you can let the system run in Feed-in or whatever you use in normal daytime running.

This is what Will recommended in the past to calibrate BMS SoC.

I am adding a second 6kw inverter but don’t have solar that feeds the batteries directly and it’s only 2kw anyway so will plan to calibrate with 12kw of inverter but am also planning on a significant solar plan 14kw if I can and then we should be in good shape!

Thks

J

Aha, well forget about PV then

To keep them reading right, best pencil in a monthly or quarterly calibration going forward.