How to Stop your EV Charging from the Tesla Powerwall Home Battery

How to Stop your EV Charging from the Tesla Powerwall Home Battery

Our experience is that the Powerwall can be configured to automatically prevent discharging whilst the EV is charging overnight. We do this by putting the Powerwall into Time Based control mode, configuring an energy tariff with a period overnight of cheap-power, and then scheduling the EV to charge only during this period.

This configuration signals to the Powerwall that there is the least value to the owner in discharging during the period when the EV is charging. It relies on the built in control algorithm to choosing not to discharge energy during this period.

Note that the Powerwall won't discharge any energy during this off-peak period, so it won't discharge for your EV charging, but it also won't discharge to meet any home loads.

If you're on an energy tariff that has varying rates at different times of the day, ensure you align your EV charging period with the time that your energy rates are the cheapest.

If you're on a flat rate tariff (the same price for energy any time of the day) with your electricity provider, you can still configure the tariff in the Powerwall (with peak prices during the early evening and off-peak periods overnight) as it still provides the same signal to the battery as to the best time of day to charge and discharge.

Step 1:

  • In the Tesla app, set the Operation Mode to: Time-Based Control
  • Set the Energy Exports to: Solar
  • Set Advanced Options - Grid Charging: No

Step 2:

  • Configure a rate plan in the Tesla app for your Powerwall
  • Importantly: set a super off-peak period matching the overnight charging period for your EV.
  • Ensure that the buy price for this period is the lowest of any of the periods you have defined in the tariff.

Step 3

  • Configure a scheduled charging period in Charge HQ to match the Super Off-Peak period you have defined in the rate plan above in the Tesla app.