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Sentry mode battery drain

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pdk42

Active Member
Jul 17, 2019
1,741
1,914
Leamington
I've played a bit with Sentry Mode, but haven't really found it that useful yet. However, I parked up early yesterday at a train station car park so thought I'd give it a try. 36 hours later, the battery has dropped from 80% to 72%. That's about 7kWh and maybe 25 miles of range. It's an enormous amount to run a dashcam. I notice from Teslafi that the car remains "Idling" rather than sleeping which I guess explains the problem. Means that the computers are drawing about 200W constantly.
 
Left my MS 75D 2017 at valet parking at Gatwick south terminal for 9 days last week, 62% on arrival, 13% on collection, Sentry mode was on. 13% was not enough to get to any supercharger. Fortunately there are two PodPoint chargers (i.e. two charging posts with two sockets in each, allegedly 22kW) in the Orange short-stay car park that gave enough charge to get to Heathrow T5 SC.

I did not use the app to contact the car while away.

Valet parking had the car at an off-site car-park but apparently not far away. Seems likely that Sentry mode was the culprit.
 
Left my MS 75D 2017 at valet parking at Gatwick south terminal for 9 days last week, 62% on arrival, 13% on collection, Sentry mode was on. 13% was not enough to get to any supercharger. Fortunately there are two PodPoint chargers (i.e. two charging posts with two sockets in each, allegedly 22kW) in the Orange short-stay car park that gave enough charge to get to Heathrow T5 SC.

I did not use the app to contact the car while away.

Valet parking had the car at an off-site car-park but apparently not far away. Seems likely that Sentry mode was the culprit.

The curious thing there is that Sentry Mode is not supposed to operate once the battery gets to 20%. I can only think that it got down to 20% pretty quickly and then lost the last 7% afterwards.
 
I was in denial about the power consumption of Sentry mode, so I did my own controlled experiment in my home garage, from which I calculated 231W or about 1.5 km/hr. Yes, it's high, and higher than I thought reasonable. But there's undoubtedly some practical reason for it, which I haven't read. Hopefully Tesla will figure out how to reduce Sentry Mode power consumption with a future SW release.
 
During the HW3 presentation Elon taled abot the importance of trying to keep computing power under 300w/hr. So I'm not suprised that stationary the car would still use 200w/hr with sentry mode. It's the difference between running a small dedicated cam=> recorder and running a whole computer and operating system for inputs from peripherals.
 
I monitor my domestic supply and I also noticed that with the car plugged in and sentry on the background usage in the house went up by about 0.25kwh. But I think we know the reason why. The car was never designed with Sentry mode in mind it was a software addon so when it is running the entire computing system capable (allegedly) of running FSD is fully powered up.
Since Sentry Mode has been so wildly popular I can see future models coming with a co-processor to make running the cameras in Sentry mode more energy efficient. We will get software updates that will make it better e.g. the ability to review on the screen etc probably but unfortunately we are probably hardware constrained on the power usage front.
The price of early adoption i'm afraid
 
How easy is it to turn on/off from the menu? I think I would be prepared to have the drain if I was parked in a public carpark doing the weekly shop but not if / when parked on the drive at home (with cctv pointing at the car anyway).

I assume it needs to be on to function as a dashcam while driving too? I guess there would be no real additional drain while driving as the computers will be used anyway?
 
How easy is it to turn on/off from the menu? I think I would be prepared to have the drain if I was parked in a public carpark doing the weekly shop but not if / when parked on the drive at home (with cctv pointing at the car anyway).

I assume it needs to be on to function as a dashcam while driving too? I guess there would be no real additional drain while driving as the computers will be used anyway?
Sentry Mode? you can turn it on and off from the top left of the in car display or from the app with a single press.
Don't think from memory it stays on. so each time you stop you have to chose to enable it before you leave the car.

If you are on the drive and plugged in obviously it won't affect the battery but it will still cost about 3-4p per hour in juice at normal rates. So could easily cost you over £100 per year if left on over night ever night.

As you say, when driving its on all the time anyway so no options there.
 
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I started switching sentry mode off at home because the drain from having it on all the time was completely unreasonable.. maybe 70% of battery in a week. Switching off at home cuts that by about 2/3. I really hope tesla manage to get that usage down significantly.
 
This thread is a few months old now but wondering if my experience this week is about right or excessive!

battery has dropped from 86% to 61%
in 5 days

only sentry mode on.... 25% seems huge to me in 5 days! (And I know 86 was a bit high to leave the car parked on I was just learning about the new charger!)

are there settings where you can reduce sensitivity or the triggers? Or is this simply the Energy cost of sentry mode?
 
This thread is a few months old now but wondering if my experience this week is about right or excessive!

battery has dropped from 86% to 61%
in 5 days

only sentry mode on.... 25% seems huge to me in 5 days! (And I know 86 was a bit high to leave the car parked on I was just learning about the new charger!)

are there settings where you can reduce sensitivity or the triggers? Or is this simply the Energy cost of sentry mode?
That is just the energy cost of sentry mode.
Actually that looks quite low. Assume we are talking about an M3 LR/P then 25% is about 18Kwh. over 5 days that is 150wh per hour. I usually work on the principal of 200wh per hour for sentry so thats actually pretty good.
You have to realise the car was never designed for Sentry mode it was an after thought so to run it they have to have the whole FSD computer running all the time and that uses a lot of power.
It is such a popular feature that I imagine future models will include a low power co-processor that can run it for a fraction of the power but for now yup its going to cost you up to 200wh/hour / several hundred pounds per year if you wish to run it all the time.
if you have a drive I recommend a security camera instead. Save it for public car parks ( you can automatically exclude home so you don't have to remember to switch on and off) and never leave it on in an airport carpark when you go on holiday for more than a long weekend!
 
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Thanks @Jason71 and @Lucanesque

I’ve just been watching the drain inside the stats app / Tesla app but actually went and sat in it today to try do a software update ahead of driving tomorrow again and I assumed I would have tonnes of sentry footage of my assistant coming in and out infront of my car - getting stuff out of her boot etc..... and like you I had 2 videos - one of me coming back to it and another which was jumpy and skipped a lot but seemed to just show the street lamp flickering.... maybe a cat or a bird triggered it but def not a person!! So all that battery gone and 2 10min recordings :rolleyes:

I do think car is safe in our spaces beside our office (10ft high locked iron gates and no other access) but I think a cctv cam out on it will be perfect!

given the time it takes to charge on the 3pin plug - that kind of drain takes time to recoup as well!!