Home-AssistantConfig/config/custom_components/tesla_charge_guard

Tesla home charge verification

This small read-only adapter exposes Tesla Fleet's source sample timestamps and observes live JuiceBox MQTT current/status reports. It reuses the existing Tesla Fleet connection and credentials. It sends no vehicle or charger commands. Native Home Assistant scripts in the vehicle package own protective stops, notifications, investigation dispatch, and restart review.

Before a protective command, the package requests fresh Tesla data to check vehicle scope. A new home charger session with missing Tesla data gets an incident refresh within a minute. A missing vehicle identity still prompts investigation/critical home-charger checks, but does not authorize stopping a vehicle elsewhere. A fresh away or DC report vetoes commands even when the current field is missing. A fresh zero-current home-charger report can clear the home incident while the vehicle is charging elsewhere.

tesla_charge_guard.snapshot returns an assessment and fires tesla_charge_guard_report. refresh: true requests one refresh with a 25-second timeout; it does not wake the car. A sleeping/rate-limited vehicle can return cached data, which remains unverified. Tesla samples expire after 120 seconds, JuiceBox current/status reports after 60 seconds. Retained MQTT messages are ignored. Fresh away/DC reports veto home stop commands. Source data with missing current, invalid current, unknown charging state, or a future timestamp is not accepted as evidence of stopped charging.

Missing current/status fields also start the monitoring dwell even when the Frequency heartbeat keeps arriving. The first minute after setup allows live reports to arrive. A fresh excessive-current reading still triggers protection when its status field is missing; a fresh positive reading cannot be overridden by another source's zero. A fresh NoPower plus zero confirms stopped charging without forgetting that the vehicle remains plugged in.

The operational guardrail is 18 A around the intended 16 A home rate. This is not a replacement for electrical protection. A successful stop command is not proof of a stopped vehicle; the package requires a fresh zero-current report. Its restoring verification timestamp records the request and existing source timestamps, allowing up to five seconds of clock skew. A later source sample must exceed that boundary, including after HA restarts. Invalid future samples cannot move the boundary indefinitely. Successful verification clears the critical incident and its matching notification; human restart review remains.

The adapter uses the installed Tesla Fleet runtime coordinator, so its contract must be checked after Home Assistant upgrades. If the vehicle cannot be found, the result becomes unverified. It retains no credentials, VIN, or coordinates in the returned snapshot. MQTT acquisition timestamps are intentionally kept in memory; after a restart, a new non-retained report is required.

The package's restoring session helper remembers a verified home connection across power loss or HA restarts. It conveys last-known scope, never freshness; only a fresh unplugged/away report ends that scope. This allows a five-minute protective stop even while the Tesla integration is still reconnecting.

The Car view exposes the restart-review helper. Clearing it acknowledges review and permits subsequent home charging; it does not start charging. Confirm the home current limit is 16 A and review the incident before clearing it. The monitoring warning and restart-review warning remain separate from an unresolved critical stop. Source snapshot sensors/events are excluded from recorder noise; aggregate incident sensors and curated JUICEBOX log entries remain recorded.