Yes, I think they only do the Hanchu stuff and are getting a good deal off the supplier.How wedded to Hanchu are the installers? I'm asking as those Hanchu 5.12kWh batteries appear to be about £1900 ex vat whereas Fogstar (yes, the same Fogstar that do van batteries) do a 16kWh for about £1500 and a 32kWh for £2750 ex vat. Same for the inverter, you can get a Victron for less than that Hanchu by the look of it. I suspect the price of the backup functionality might go up here though, there's no equivalent to that Hanchu gateway so you'd need a few extra switches and the like I'd think. Your annual usage implies an average daily usage of around 14kWh so it would be nice if the batteries could at least see you through an average day.
It's going to come down to the installer though, if they install Hanchu all day long they're unlikely to want to deviate into something they're not familiar with.
I've been investigating t'interweb and it seems the EV charger should not 'see' the batteries to stop battery drain when plugged in.
Yeah daily average is about 14kwh, but when you take out the EV usage (around 15-20% and not using washer/dryer, dishwasher etc in the event of a power cut, I reckon a 10.2kwh of battery should be fine in the event of a powercut.
Most of the big players don't cover my area and seem to be 2-5k more for a similar system
