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Ensuring solar power charging only of both powerwall and car possible?

Ensuring solar power charging only of both powerwall and car possible?

With a Tesla charger and Powerwall 2, is it possible to configure these so that they both only charge using excess solar?

I know the Zappi charger will do this for the car charging, but I would hope that the Tesla would enable you to configure priority and minimum charge via an app?

For example, I may want to configure so if my car is charged < 30%, charge at 32A minimum
If car is > 30%, charge at minimum 6A but use any excess solar on top

Plus similar configs for the powerall.

Can this be done?

peter.ebdon | 8 febbraio 2018

Done some research on this since posting and seems it can't unless you use an OpenEVSE charger instead and use code to control the charge rate. Some have modded the Tesla charger to allow it to be controlled but that's messy and has safety approval issues.

Tesla should be able to do better with their app as they have access to all of the necessary elements. The app can already read solar production, grid import / export and home consumption.

The car charge rate can't currently be controlled via the API - it can only be turned on or off.

So all Tesla needs to do is update the firmware of the car to allow the charge rate to be controlled via the API (restricted just to them if need be) and then update the app so that you can set your battery / car charge settings. It can then adjust the charge rate of the car according to SOC of battery and car in conjunction with your preferences to use your solar production as much as possible without drawing more from the grid than necessary to achieve your desired charge by a certain time of day.

sashton | 9 febbraio 2018

@peter I am very much in the same boat as you. I have a Zappi but while you can prioritise the excess to either go to the car or the PW there is no API (promised from myenergi but no sign of it yet) so altering the priorities requires a config change on the charger panel and moving CT2 ... not a very satisfactory solution.