AC battery charger , Max Soc AC charge prevents PV excess stored on battery

#1 duncanstrachan11 2025-03-18

I m having problems getting a good strategy setup as well. I want to use PV energy and and excess PV to go directly to the battery instead of it going to the grid. Eco mode should do this.
We are on Octopus Cosy tariff, so no export energy payments.
Also want to have enough battery charge to let the house run on battery during the Octopus peak tariff between 16:00 and 19:00 and preferably till 22:00 when cheap period kicks in.
If I setup a charge cycle between 13:00 and 16:00 with a AC Max SOC % specified for when there are no sunny days to charge the battery. Now the issue is that when the MAX SOC is reached the excess PV is not stored in the battery but goes to the grid. ried tiered charging strategy, does not really work. When you start with a reasonable high SoC , no PC excess is used till the end of the tier model.
This is not what I expected. Contacted GivEnergy, their response was, this behaviour is what most customers want. Not sure about this.
I would think that when ECO mode is on, EV excess should always got to the battery until the mac SOC is reached as is specified in the battery specification section.
Any thoughts about this please.

#2 DD 2025-03-18

duncanstrachan11 We are on Octopus Cosy tariff, so no export energy payments.

No reason you can't be paid for export while on Cosy:
https://octopus.energy/help-and-faqs/articles/which-export-tariff-can-i-combine-with-my-import-tariff/

#3 duncanstrachan11 2025-03-18

DD
Didn't know that, just looked at Cosy tariff details. Not a bad idea!, still would like GivEnergy to create a consistent behaviour when ECO is selected.

#4 DD 2025-03-18

duncanstrachan11 still would like GivEnergy to create a consistent behaviour when ECO is selected.

Can just as easily argue that they have given consistent behaviour when a charging slot is enabled: if SoC is less than the target, actively charge it, otherwise pause it. You can't label it as strictly AC charging, since it will still use solar first. (Well, my hybrid inverter will, at least.) So if I have max charging rate set to 2kW, and there's 1kW of excess solar, it will use that plus 1kW from the grid to charge, until it reaches the target SoC.

#5 duncanstrachan11 2025-03-18

DD
Hmm , labels on a time slot : AC Charge

It does make sense that during AC charge PV power is used to, but it also says AC charge upper limit SOC, this if in ECO mode should not include upper limit for PV power charge IMHO