I parked my car at the airport a week ago, and the battery was probably around 60%. I got a message last night that sentry mode (which I should have turned off) has turned off because the battery is now at 20%. We’ll be gone another week and I’m worried the battery will keep dropping. I’ve heard I should stop opening the app. Is there anything I can do to preserve the battery while we’re gone?
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Soul Surfer
Cancervivor, tech geek & musician
You pretty much answered your own question. Fortunately the car has good programming to self-preserve. Sentry sucks power. Depending on the weather, you will definitely lose some more but might have enough to get you to a SuperCharger on your way home. Worst case scenario, borrow a portable generator to top up. But you should be fine.
Personally when traveling for more than two weeks we always take an Uber as it turns out to be cheaper than parking for 3 weeks or more, in our case. Best of luck.
Personally when traveling for more than two weeks we always take an Uber as it turns out to be cheaper than parking for 3 weeks or more, in our case. Best of luck.
PianoAl
Active Member
The car being "awake" uses about 0.25kW (per other posts on this forum).
That amounts to at least 6kWh or about 8% per day.
Keeping Sentry/cameras activated and constantly connecting to the car via the app likely ups that energy consumption.
The car "asleep" (sentry off) should not have any noticeable drain in one day. The small parasitic drain may amount to a few % over the course of a week/month. Nobody really knows.
The % drop in battery SOC most people see when they wake up the car is likely due to BMS recalculating due to change in battery temp.
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zoomer0056
Active Member
Use the Tessie app to monitor your car without waking it up. I've been using it for almost two years now. With sentry off, and no wake ups, you can get 1% loss or less every two or three days.
PianoAl
Active Member
Yup.
Like this:
Park on monday, 13%
Start to charge it on Friday night from 13%:
I work for one week about one week each month. My logs show the same each week the car is parked for about a week at the time. (This time it was not a whole week, but it didnt drop a single percent either).
Using scan my tesla and teslalogger i see the 0.1 kWh, or about 0.1 - 0.15% (depending on the car) reduction from the nominal remaining each day.
0.1kWh/day = 4 Watts! Not much.
In cold weather the displayed SOC is adjusted down from the real/measured SOC (most certain to compensate for cold losses etc.) and this only happens “first night” so when the SOC drops for example 3-4% the forst night due to a cold batt, this will not continue other nights.
The cold battery drop is displayed in the app with a blue part of the charging slider:
There can also be a drop just efter parking when the BMS gets the opportunity to measure the real SOC (as SOC during a drive is estimated). If the BMS does an overestimate the SOC will drop when BMS reads the true SOC after the drive.
It can be hard to distinguish these from each other. But as a rule of thumb:
-The BMS adjustments after the drive will happen (most of the adjustment, at least) within 30 minutes after the drive (I have logged data covering this).
- The display of the cold battery will take 3-12 hours or so, depending on ambient temps and the cell temp when parking.
- Sentry use ~ 250W (a bit depending on hardware, I have seen 220W (model 3 intel atom) to 290W (model S AMD Ryzen).
- this is roughly 6kWh / day so between 6-10% depending on car and hardware.
- The car use the same power awake, so sebtry off but not sleeping - same loss/ day.
If you see 6-10% / day loss, the car does not sleep. Either sentry is on or it just aint tired. Reboot the complete car might help in that case.
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