Automatic rate-based Tesla charging set to lower electricity bills in new update

Tesla is preparing to introduce automatic EV charging based on smart algorithms that will minimize the use of high grid electricity prices. A code string in the new Tesla App 4.46.5 update reveals a rate-based charging feature that is not yet in the release notes.

The string refers to an upcoming communication protocol between a Tesla Powerwall and home charging gear like the Universal Wall Connector that costs $650 on Amazon, which will introduce rate-based charging.

What this would mean in practice is that the Tesla home charger will pump the vehicle full of electrons via the Powerwall based on electricity pricing and source, like grid or solar, rather than time of day on TOU  utility plans.

According to Tesla's mobile app designer Alex Guichet, this feature will arrive in the immediate future and is already undergoing pilot testing, hence the presence of its code strings in the newest app version.

The Powerwall’s energy algorithms optimize the perfect time for the Wall Connector to charge your car. It shoots for the lowest costs based on your Time-Of-Use rate plan, and works with Teslas and non-Teslas. The goal is to be more intelligent than the simple schedule the Wall Connector supports now, which isn’t price aware! (If it makes sense for your tariff, sure, the Powerwall may discharge, but it’s more likely to be solar and grid too!)

The strings powerwall_x_wall_connector_rate_based_charging_min_hours_charging_set, and wallConnectorSupports4HourChargingFactory indicate a more granular approach to charging based on electricity costs rather than the current time-based schedule that Tesla already offers via the app.

The latter ability, however, will come with the next Wall Connector firmware version 25.26 that is yet to be released as an update.