Glossary
This page defines the key terms used across BYD EV Pro documentation. When a term has a specific meaning in this system, it is listed here.
Car App
Section titled “Car App”The main BYD EV Pro application, installed directly on the BYD DiLink head unit inside the vehicle. It is the core of the ecosystem — all other components connect through it.
Companion App
Section titled “Companion App”The mobile app (available for Android and iOS) that pairs to the Car App and provides remote access to the vehicle from a phone. Requires an active license.
Optional hardware that installs inside the vehicle. Adds proximity auto-lock/unlock, GPS tracking while the vehicle is off, and the ability to receive remote commands when the head unit is asleep. T-Box is a brand name — do not call it “Tracker”.
DiLink
Section titled “DiLink”The Android-based head unit operating system used in BYD vehicles. The Car App runs on DiLink. The specific features available depend on the DiLink version (3.0, 4.0, 5.0, 5.1, or 6.0) and the vehicle model.
Head unit
Section titled “Head unit”The touchscreen computer in the centre console of a BYD vehicle. This is where the Car App is installed. Also referred to as “the DiLink head unit.”
Pairing
Section titled “Pairing”The process of linking the Companion App to the Car App by scanning a QR code. Pairing also establishes the security tokens needed for remote access. In T-Box pairing, additional proximity data is exchanged.
License
Section titled “License”A software entitlement that enables connected features. Without an active license (or during a valid trial), Companion App access, Home Assistant integration, and Telegram notifications are unavailable. The Car App dashboard and local controls work regardless.
A 14-day period during which all licensed features are available at no cost. One trial is allowed per vehicle (by VIN) or per installation. The trial must be explicitly activated in the Car App.
Grace window
Section titled “Grace window”A 72-hour buffer during which the Car App continues to grant access to licensed features even if it cannot reach the internet to verify the license. After 72 hours offline, licensed features stop working until connectivity is restored.
Home Assistant
Section titled “Home Assistant”An open-source home automation platform. BYD EV Pro integrates with it through a custom HACS component that receives vehicle data via webhook and creates sensors and a device tracker.
Home Assistant Community Store — a community-managed extension system for Home Assistant that allows users to install third-party integrations. The BYD EV Pro Home Assistant integration is distributed through HACS.
Webhook
Section titled “Webhook”An HTTP request that the Car App sends to Home Assistant when vehicle state changes. The Home Assistant integration listens for these requests and updates entity values accordingly.
Proximity
Section titled “Proximity”The T-Box feature that detects the Companion App’s Bluetooth signal and automatically locks or unlocks the vehicle based on how close or far you are. Requires T-Box hardware, the Companion App with Bluetooth enabled, and a pairing that includes T-Box proximity data.
SOC (State of Charge)
Section titled “SOC (State of Charge)”Battery charge level, expressed as a percentage. Shown on the Car App dashboard and sent to Home Assistant.
SOH (State of Health)
Section titled “SOH (State of Health)”A measure of the battery’s current maximum capacity relative to its original design capacity. A healthy battery shows SOH close to 100%. SOH is shown in the Car App battery detail section, where the vehicle reports it.
TPMS (Tyre Pressure Monitoring System)
Section titled “TPMS (Tyre Pressure Monitoring System)”Sensors built into the vehicle that report tyre pressure to the head unit. The Car App shows TPMS values on the dashboard where the vehicle exposes them.
OTA (Over-the-Air)
Section titled “OTA (Over-the-Air)”Firmware updates delivered wirelessly rather than via a physical connection. T-Box firmware updates are OTA — the Car App downloads the update and transfers it to the T-Box over Bluetooth.