FoxESS Community - Owners & Installers Forum

Hopefully getting a heatpump (5kw) installed in the next couple of months.
Currently I have a split 5.2kw solar array and an EP11. I mostly export as my electric use is covered by the solar and is well under the battery capacity on a daily basis. Considering that I will need to look at a further EP11 in due course but trying to figure how much of the daily heat pump usage can be offloaded to the off peak period without going to a Cosy like tariff

I have been exporting the remainder of the battery after midnight and then charging up ready for the day (Eon Next cheap rate 12-7am @ 6.7p)

So when the heat pump comes online I will need the heat pump to do the overnight hot water and an initial radiator heat up to ignore the battery overnight but then run off of the battery after 7am, but I can't figure the settings to do that? Is it feasible unless I drain the battery and then charge it as late as possible to finish at 7.

What is the order of operation when Mode Scheduler is set to Force Charge (Currently 2.30am to 5.30pm and then swapped to Feed in)? Does the battery try and power items while that is set or is it set to ignore self use for that period?

Thanks

It's quiet common to set the inverter schedules to work with 'Cozy', in the scheduler you will need to set 3 Force Charger Schedules that align with the Cozy schedules so whenever the tariff is low and your heat pump is on, your batteries will also be charging (and more importantly not discharging into the heat pump).

If you set 3 separate Force Charge entries in scheduler, with times 04:00 - 06:59, 13:00 - 15:59 and 16:00 - 21:59 that will keep your battery charged.

To your specific question, if you do not want to charge the batteries on low tariff at the same time as the heat pump being used - then if you have the backup work mode you can set a schedule to that and it will preserve the battery at that SoC and use the grid for all of your house & heat pump usage.

If you do not have backup work mode, you can set a Force Discharge with a low discharge power ( say FDPwr=10 watts) and that will not allow the batteries to be used for any more than 10 watts of discharge which will hold their SoC for many hours.

Feedin work mode only sets the priority that solar will be used - that is House Load, Export (only charges battery if PV exceeds the export or inverter limits).

In Self Use that priority is House Load, Battery Charge, Export

Thanks.
Currently the plan is to set a force charge between 12am and 7am to block the heat pump using the battery for the hot water (2 hours or so) and the initial heat increase to the day temp.
Plus any washing or drying that needs doing from time to time.
I'm hoping the daily peak heat pump electric usage (including solar generation) will be below the 10kwh from the battery for heat between 7am and 12am but will have to see how things look in reality rather than as theoretical. Another EP11 would be the obvious idea but at £3000 it would be a lot of peak time electric over 3-4months and the only benefit would be the additional export available during other months