My questions are really based off confusing posts on the internet:
* how well will the zappi work with the GivEnergy?
It doesn't natively which can cause problems when using Octopus Intelligent Go because it can charge the car at seemingly random times of the day but you can use home assistant to resolve this issue. This can cause battery draining issues, the Zappi also can't tell what is solar or what is coming from the battery on a hybrid inverter.
You just need an automation which monitors the 'Octopus Intelligent Dispatching' entity and when it switches on, charge the battery, when it switches off, go back to eco mode. As you can get 7.5p import overnight and 15p export, you want to charge your battery to 100% daily and use the grid whenever 7.5p is available.
* How much do octopus control in terms of charging the car and exporting to grid?
Only charging the car on Octopus Intelligent Go, only the battery on Intelligent flux.
* I have read of people saying that the zappi drains their battery and a solution being to put CT clamps in ?places? to overcome the inverter seeing the zappi as a electrical load to satisfy by pulling from battery.
See above, charge the battery whenever the car is charging, problem solved.
It may be good practice to split your incoming electricity cables just after the meter and install the charger there anyway. You can then place the CT clamp for the hybrid inverter on the cable that goes to the house consumer unit so it will not 'see' the chargers load because its power supply is split out before the point the CT clamp is measuring. The downside of this is the energy consumption to the car will not show up in the GivEnergy dashboard. This may also not be possible depending on your electrical installation and the best place to install the chargers wiring.
Does anyone have this setup and some tips of what to ask for regarding the zappi install??
I don't have one but if you are using IOG, you just leave it in dumb mode and let Octopus control the charger. You don't want to charge the car from solar as it will lower your return.
Givenergy are also in the process of getting their charger certified with Octopus Intelligent but as far as I am aware, there is no launch date - just a thought should you want the two devices to better talk to each other. The Zappi is certainly the better product at the moment though.