Which charger do you have?
According to Octopus the Ohme Home Pro won't work with a battery.
If you just want to charge your car from the grid, any charger will do as long as it’s compatible with IO. Also consider hypervolt alongside Zappi and Ohme.
If you want to charge from solar then you’ll need a charger capable of it like Zappi or hypervolt. It’s not currently cost effective to charge for solar but that may change in the future - it’s all dependent on tariff rates.
The important thing is to make sure that when they install your charger and battery, they do it in a way which means your battery can’t ‘see’ the load from the charger otherwise it will empty itself into your car.
Basically you want it installed like this:
Meter > isolation switch > junction box which splits the supply into:
1. EV charger.
2. Everything else.
This is mainly for when the solar goes in. The battery system monitors what power you are using via a device called a CT clamp and it sends power out of the battery to match demand as needed.
You put that monitoring device on the cable going to #2 then it can’t see #1 and your car can’t empty the battery.
Your car charger can still charge from solar as it also uses a CT clamp to monitor power and you put that around the cable going to the meter and it will just grab any excess being exported.
P.S. the person you spoke to about solar is not correct, get a battery! Combining solar batteries and a tariff like intelligent go or agile will slash your energy bills. The battery creates most of its benefit in winter when there is no solar as you charge it for next to nothing from the grid (also do this in summer to maximise solar export).
Happy to pick up via PM or a dedicated thread if needed.