Charge HQ controls charging on Tesla vehicles by communicating directly with the vehicle (not the wall charger). There are two steps to enable this communication.
Tesla allows apps like Charge HQ to communicate with their vehicles via an official Third Party App access mechanism.
Access is enabled by logging in to your Tesla account, and granting access to Charge HQ. This happens at a Tesla user account level.
When you grant access, Charge HQ gains visibility of any Vehicles, Powerwalls, or Tesla solar systems connected to your Tesla user account.
The access grant mechanism includes granular control over what information we can see and what we can control.
All information collection and charging control happens via this access grant. If you have multiple Tesla accounts (E.g. multiple drivers, each with their own login):
The Third Party App access grant mechanism creates a secure token which is used by Charge HQ to authenticate with your Tesla account (via a standard oauth access grant). We never have access to your Tesla user account email or password.
When you enable Third Party App access, you will be asked to select what Charge HQ should have access to. Access permissions are grouped together into scopes, Tesla controls which permissions are in each scope. In each scope, there is information we don't need access to alongside information that we do.
For example, we don't need to know about "eligible upgrades" or "service scheduling data" but these permissions are in the same scope as "location" which we need to ensure we only control charging when your vehicle is at home.
The access scopes are:
Profile Information: Allow access to your profile information, including data such as your contact information, profile picture, and referral information
Vehicle Information: Allow access to your vehicle information, including data such as your vehicle's live data, location, eligible upgrades, nearby superchargers, ownership, and service scheduling data
Vehicle Commands: Allow access to your vehicle commands, including commands such as add/remove driver, access Live Camera, unlock, wake up, remote start, and schedule software updates
Vehicle Charging Management: Allow access to your vehicle charging management, including data such as your vehicle charging history, billed amount, charging location, commands to schedule, and start/stop charging
Energy Product Information: Allow access to your energy product information for Powerwall and solar, including data such as energy flow history, saving forecast, tariff rates, grid import, calendar, site status, time of use, and ownership
Energy Product Commands: Allow access to your energy product commands for Powerwall and solar, including commands such as updates to storm mode and off-grid charging reserve
Notes:
This step is not required for pre-2021 Model S / X vehicles.
The Third Party App access grant gives Charge HQ the ability to communicate with Tesla on your behalf, with access to the vehicles and energy products linked to your account.
In order for your vehicle to accept commands from Charge HQ, you must install a virtual key onto your vehicle via a pairing process. This key is used to securely verify that the commands are coming from Charge HQ.
To perform this step you must be logged into the Tesla app with a Tesla account that has performed step 1 (Third Party App access grant).
Charge HQ hosts a public key at http://tesla.chargehq.net. This address is registered with Tesla as part of our Third Party App. When each vehicle is paired, the virtual key (being a public key) is downloaded from this address onto the vehicle itself.
Once Charge HQ's virtual key is installed on a given vehicle, any user with access to the vehicle that has completed step 1 (Third Party App access grant) will be able to use Charge HQ with it.
The virtual key will remain on the vehicle until it is removed. This can be done via using the vehicle's touchscreen. As an owner, if you wish to prevent an authorised driver from using Charge HQ with the vehicle, you need to remove the Charge HQ virtual key.
