FoxESS Community - Owners & Installers Forum

Hi,

I recently added batteries to my solar system and am in a stage of learning and planning strategies. I have latest inverter firmware as of writing this post.
I do find bits and pieces here in the forum which may make up to a complete picture, but I also se that behavior of the inverter does change over time when firmware is updated.

So, my question is, what are the priority orders for the different usually used modes?

My guess (or perhaps hope):

• Force Charge – PV (if any) plus Grid (topped up to max charging effect) to Battery, PV to Load when battery is at maxSoC, Excess PV to Export, Grid to Load

• Back Up – PV to Battery, PV to Load when battery is full, Excess PV to Export, Grid to Load

• Self-Use – PV to load, Excess PV to Battery, Excess PV to Export when Battery is full, Battery to load, Grid to load

Help would be much appreciated, it does take a full 24h cycle, plus hoping for sunshine in the Swedish winter, to try and error

petste wrote: Wed Jan 29, 2025 11:27 am Hi,

I recently added batteries to my solar system and am in a stage of learning and planning strategies. I have latest inverter firmware as of writing this post.
I do find bits and pieces here in the forum which may make up to a complete picture, but I also se that behavior of the inverter does change over time when firmware is updated.

So, my question is, what are the priority orders for the different usually used modes?

My guess (or perhaps hope):

• Force Charge – PV (if any) plus Grid (topped up to max charging effect) to Battery, PV to Load when battery is at maxSoC, Excess PV to Export, Grid to Load

• Back Up – PV to Battery, PV to Load when battery is full, Excess PV to Export, Grid to Load

• Self-Use – PV to load, Excess PV to Battery, Excess PV to Export when Battery is full, Battery to load, Grid to load

Help would be much appreciated, it does take a full 24h cycle, plus hoping for sunshine in the Swedish winter, to try and error

Hi, yes you are pretty close but the answer to Force charge is not always straight forwards and depends on the way you do it, the inverter model and firmware version but i'll try and cover the bases.

• Force Charge – PV (if any) plus Grid (topped up to max charging effect) to Battery, PV to Load when battery is at maxSoC, Excess PV to Export, Grid to Load

- varies depending on :

If you use the charge periods to charge (not the scheduler), then Force Charge – PV (if any, else Grid) to Load, PV (if any left, else Grid topped up to max charging effect) to Battery : PV (if any, else Grid) to Load when battery is at maxSoC, Excess PV to Export

If you use the scheduler 'force charge' mode with maxSoC set to 100% then (on latest firmware) PV (if any, else Grid) to Load, PV (if any left, else Grid topped up to max charging effect) to Battery : PV (if any, else Grid) to Load when battery is at maxSoC, Excess PV to Export.

If you use the scheduler 'force charge' mode with maxSoC set less than 100% (on latest firmware) before the inverter reaches maxSoC - PV (if any, else Grid) to Load, PV (if any left, else Grid topped up to max charging effect) to Battery : PV shuts down when battery is at maxSoC, Grid to Load.

• Back Up – PV to Battery, PV to Load when battery is full, Excess PV to Export, Grid to Load

- Not quite, backup maintains the current battery SoC state, but -

Back Up – PV to load, PV excess to Battery, PV (any over battery charging limit) to Export : When battery is full, PV (if any else Grid) to Load, Excess PV to Export

• Self-Use – PV to load, Excess PV to Battery, Excess PV to Export when Battery is full, Battery to load, Grid to load

In Self Use PV will always go to load first , Excess PV to battery, Excess PV (any over battery charging limit) to Export : When Battery is full, PV (if any, else Battery) to Load. When no solar if Battery > minSoC Battery to load (else grid).

Irrespective of mode PV will always be used to cover Load first before anything else ~ battery, export etc..

I hope I got that right, i'm going for a lie down now....

Thanks Dave, that was a very extensive answer, really good and easy to follow