Growatt Battery Setting Help

QrizB

Could you please expand on the effect of the "AC Charge" toggle?

Welcome to the forum @SleeperService !

Unless any other Growatt users happen by, you might have a long wait. This thread is originally from 2023 and the post before yours from @Mattyb_UK is a year old, and he rarely comments (one comment in 18 years).

The OP @pcgtron is still active on the forum so your best hope is that they hnow the answer.

Reed_Richards

As an experimentalist, I would try turning off "AC Charge" to see what happens. If the battery then fails to charge overnight from the grid then turn it back on. If it still does charge overnight then the meaning of the setting remains a mystery, but an inconsequential one.

SleeperService

I ran that experiment last night … and with “AC Charge” disabled, the system did not charge my house battery from the grid. Whereas on all previous nights, when “AC Charge” was enabled, the grid charged my house battery to 100% overnight. Thanks, @Reed_Richards

So I think that is now clear : if you want to allow the grid to charge your house battery when in Battery First mode, then enable “AC Charge”.

SleeperService

However, I am still trying to find an answer to my underlying question : when in “Load First” mode during daytime peak rates, how can I prevent my battery from being drained when Octopus Energy very generously decides to charge my car from the grid ?

One way would be to switch from “Load First” to “Battery First” when that happens, and back again afterwards, but I doubt there’s any way I can configure Growatt to switch automatically like that.

QrizB

However, I am still trying to find an answer to my underlying question ...

The usual answer to that is to move your inverter's current transformer (CT) so that it doesn't sense the load from your EV wallbox.

See for example this thread:

https://forums.moneysavingexpert.com/discussion/6650502/intelligent-octopus-go-and-home-batteries