What is phantom drain?
Phantom drain is the gradual loss of battery a Tesla experiences while parked and not in use. Common causes are Sentry Mode, Cabin Overheat Protection, preconditioning, trickle charging via the Tesla Mobile Connector, and third-party apps polling too aggressively. A natural daily loss of 1–3% is normal — beyond that is abnormal. Note that phantom drain is completely unrelated to phantom braking, which is unintended hard braking during Autopilot.
What is phantom drain (definition)
Phantom drain refers to the phenomenon where battery state of charge decreases while the Tesla sits parked. Tesla vehicles never fully "power off" — sensors and network functions stay on standby continuously.
A daily loss of about 1–3% is normal and expected. If you see consistent loss above 5% per day, one of the causes below is likely in play.
The similarly named phantom braking is when Autopilot brakes hard for no apparent obstacle. That's a safety issue during driving and is a completely separate phenomenon — don't confuse the two.
Common causes of phantom drain
- Sentry Mode — perimeter monitoring while parked can use 1–3 kWh per day
- Cabin Overheat Protection — A/C cycling on hot days to keep cabin temperature in check
- Preconditioning — Smart Summon, Scheduled Departure, or pre-drive battery warm-up
- Trickle charging via Tesla Mobile Connector — a weak outlet may only cover heater draw, not net charge
- Third-party apps polling too aggressively — minute-by-minute polling prevents the car from sleeping
- Continuous Wi-Fi / LTE connectivity — including OTA update downloads in the background
- Extreme ambient temperatures — cold-climate battery heaters draw current to protect the pack
How to reduce phantom drain
VoltKeep automatically detects parked battery loss and notifies you. For a deeper diagnosis breakdown and 5 actionable fixes, see our blog post:
Automatic detection in VoltKeep
VoltKeep continuously logs your parked SoC and sends a push notification when daily drain exceeds your threshold.
- Available on the free plan
- Logs the timestamp of abnormal drain along with the immediately preceding state (Sentry Mode on/off, etc.)
- Long-term trends reveal patterns like "worse in summer" or "worse at certain parking spots"
Don't let Tesla phantom drain slip under your radar.
Automatic phantom drain detection is included in the VoltKeep free plan.
Get it on the App Store