I wrote recently about the Tesla and the charge loss while sitting at the airport. While a little worrisome, I knew it was something I could live with, and even get around. A few of the parking places near the airport have long term charging, so it’s not the end of the world.
But it felt strange.
I don’t always plug in the car at home, and after a day or two, I might lose 1%, but nothing like the 8% we were losing each day. I decided to do a little investigating and see what other owners have experienced as I see plenty of Teslas parked at Wally Park, where I usually leave my car.
I saw more than a few people note that there are two reasons you usually use significant charge. First, people keep checking on their car in the app, and this prevents it from going to sleep.
Second: Sentry mode.
Sentry mode is essentially a combination car alarm and constant dashcam. The car is always recording things, which means the car and computer are always active. While the car isn’t moving, there is still power being burned when it is online.
Sentry Mode is especially active when it detects people near the car. In a busy parking lot at the airport, this means every 5-15 minutes, someone drives past. Certainly not longer than 30 minutes.
When I checked my TeslaMate stats, I could see the problem easily. In the image below, my latest trip is 4/28 to 5/2. On the right side of the image, the car is almost always asleep. If you look towards the left, from 4/14 to 4/18 was my second trip. This was the one where I lost 25% in three days. I can go back and see the trip before that where I lost quite a bit as well.
I turned off sentry mode between the last two trips and it made all the difference. We were gone 4 days this time and we lost around 1% of charge. I no longer worry about a two week trip out of the country with this car. I might be concerned for 30 days, but maybe not.
The vampire drain is shown below. You can see the difference in trips here.
A normal day at home has the car mostly asleep, which makes sense. Sentry mode is disabled at home (or work) if you set that. I had, but didn’t think about the airport. While it could help me detect who caused damage to the car if something happens, the lot tracks who is in and out and where they park, so they likely could help me pinpoint who damaged the car if I had an issue.
I’m glad to solve that, and more importantly, I hope more people realize the Sentry mode, while great, can eat up battery over time.
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