Sentry Mode Battery Usage

[DMLou]

I'm getting my new M3 next week, but I have a couple of weekend trips coming up where I'll have the car in a parking garage without any charging available for said weekends. If I were to have Sentry mode enabled during those times, how much battery drain would I be looking at?

 

[Big Earl]

About 200 Watts continuously when Sentry Mode is active.

 

[AlanSubie4Life]

About 200 Watts continuously when Sentry Mode is active.

I'm getting my new M3 next week,

Translating this to three vehicle possibilities:

2020 SR+: 200W/(200Wh/rmi) = 1 rated mile/hr

2020 AWD 18": 200W/(230Wh/rmi) = 0.87 rated miles/hr

2020 3P+ 20": 200W/(248Wh/rmi) = 0.81 rated miles/hr

 

[DMLou]

Okay, so round it off to about 1 mile/hour for my model to be safe... Works for me.

 

[JDFPHOTO]

I will be out of town for two weeks and I would like to keep sentry mode on while it's parked at the airport. How much will it drain the battery? 2020 M3 LR AWD.

 

[AlanSubie4Life]

I will be out of town for two weeks and I would like to keep sentry mode on while it's parked at the airport. How much will it drain the battery? 2020 M3 LR AWD.

Assuming it's still 200W for Sentry (it's been months since I've seen any reports of measurements, and I never pay attention to usage since I rarely use it, but it's probably similar):

2020 AWD 18": 200W/(230Wh/rmi) = 0.87 rated miles/hr

If you have 19" you can scale this number by 304/322 (0.82 rmi/hr)

So (for 18"):

14days*24hr/day*0.87rmi/hr = 292 rated miles over 2 weeks, 14 days.

So, assuming you have 322 rated miles at 100% still (may not be valid; that's why we don't do these calculations using %!!!), if you start at 90% (somehow), it'll turn off at 20% after about 11 days, and you'll probably have 15% battery charge left when you get back.

This is just an estimate, of course. But it's in the ballpark unless they somehow cut Sentry Mode to 100W or something (doubtful).

 

[JDFPHOTO]

Assuming it's still 200W for Sentry (it's been months since I've seen any reports of measurements, and I never pay attention to usage since I rarely use it, but it's probably similar):



If you have 19" you can scale this number by 304/322 (0.82 rmi/hr)

So (for 18"):

14days*24hr/day*0.87rmi/hr = 292 rated miles over 2 weeks, 14 days.

So, assuming you have 322 rated miles at 100% still (may not be valid; that's why we don't do these calculations using %!!!), if you start at 90% (somehow), it'll turn off at 20% after about 11 days, and you'll probably have 15% battery charge left when you get back.

This is just an estimate, of course. But it's in the ballpark unless they somehow cut Sentry Mode to 100W or something (doubtful).

Thanks so much for the info. I have 19" wheels. So, by your formula I would use about 276 rated miles over two weeks or about 20 rated miles a day?

 

[AlanSubie4Life]

o, by your formula I would use about 276 rated miles over two weeks or about 20 rated miles a day?

Yep. Again, assuming you and the comparable 18" car have 322 and 304 rated miles at 100% (not a good assumption), you'd both use the same 91% of your battery. You would use 276 rated miles, they would use 292 rated miles. 91% for both with that assumption (may well be different % in reality, even if the usage numbers are exactly 276 and 292, due to capacity loss, which makes each % a variable quantity of energy, so those % numbers can vary substantially).

If you do end up doing this and tracking it, feel free to report back with the latest numbers. Accurate numbers would be the only way we'd know whether Sentry Mode has been optimized at all (which again, I doubt).

 

[Gasaraki]

Translating this to three vehicle possibilities:

2020 SR+: 200W/(200Wh/rmi) = 1 rated mile/hr

2020 AWD 18": 200W/(230Wh/rmi) = 0.87 rated miles/hr

2020 3P+ 20": 200W/(248Wh/rmi) = 0.81 rated miles/hr

Why would the size of the wheel matter when we are talking about sentry mode and the usable battery is the same between the LR and Performance...

 

[jrweiss98020]

about 20 rated miles a day?

About right. On an 8-day trip, I started at just over 200 mi remaining, and it was down to just over 50 when I returned.

 

[AlanSubie4Life]

Why would the size of the wheel matter when we are talking about sentry mode and the usable battery is the same between the LR and Performance...

I'd appreciate if you would remove the disagree: You are absolutely right, it does not make any difference! Which is what my numbers say! If you convert these numbers to kWh used per hour of Sentry mode, you will find they are all the SAME.

Yes, the choice of wheels DOES matter (for 2020 vehicles, not for 2018/2019), since changing those wheels changes the amount of energy per rated mile (as displayed to the user), with no change in battery capacity. So the rated miles will click off at different rates per hour when Sentry is engaged (since obviously the energy used per unit time in Sentry mode doesn't change based on which wheels you have selected!!!). Those different rates (rmi /hr) will result in the SAME energy used per unit time (kWh/hr) (since the rated miles have different energy contents).

 

[jjrandorin]

I'd appreciate if you would remove the disagree: You are absolutely right, it does not make any difference! Which is what my numbers say! If you convert these numbers to kWh used per hour of Sentry mode, you will find they are all the SAME.

I am guessing that he didnt understand that, while the energy used is all the same, the distance you can actually go with that energy is different, which is what your numbers / formula's are showing.

To answer his question in laymans terms "the wheel size makes a difference in how far you can go with the energy thats left, not on how much energy is used. The question was how many miles an hour does sentry mode use". Different size wheels effect how far a tesla can go with a certain amount of energy, so produce a different formula even though the energy usage is the same".

EDIT: I think you were editing your post to say the same thing I said above. I wasnt trying to repeat what you said here, or put additional words in your mouth, lol.

 

[Gasaraki]

I'd appreciate if you would remove the disagree: You are absolutely right, it does not make any difference! Which is what my numbers say! If you convert these numbers to kWh used per hour of Sentry mode, you will find they are all the SAME.

Yes, the choice of wheels DOES matter (for 2020 vehicles, not for 2018/2019), since changing those wheels changes the amount of energy per rated mile (as displayed to the user), with no change in battery capacity. So the rated miles will click off at different rates per hour when Sentry is engaged (since obviously the energy used per unit time in Sentry mode doesn't change based on which wheels you have selected!!!). Those different rates (rmi /hr) will result in the SAME energy used per unit time (kWh/hr) (since the rated miles have different energy contents).

And this is why kids, the miles display is totally useless. Disagree removed.

 

[AlanSubie4Life]

And this is why kids, the miles display is totally useless. Disagree removed.

Thanks! I certainly understand the sentiment here, but for the purposes of this discussion, worth noting the following:
(Assuming no changes to Sentry Mode consumption by Tesla):

%battery/hr allocated to Sentry will change over time; it could increase "substantially" over time (meaning up to 10-15% faster, depending on capacity loss).

rmi/hr will always be roughly the same, for a given wheel selection.

Users can make their own choices about the relative utility of rated miles vs. %. All depends on your mindset, I think. I personally prefer rated miles, since I always know how much energy I have available, that way. But it is certainly a personal preference.

 

[KuramaKitsune]

Translating this to three vehicle possibilities:

2020 SR+: 200W/(200Wh/rmi) = 1 rated mile/hr

2020 AWD 18": 200W/(230Wh/rmi) = 0.87 rated miles/hr

2020 3P+ 20": 200W/(248Wh/rmi) = 0.81 rated miles/hr

i can say, in my 2020 LR awd
it appears to eat up about 1 miles range per hour of sitting

 

[nigeldodd]

Leaving sentry mode on overnight seems to consume the equivalent of 10 miles of range, or 3 kWh, which seems rather a lot. I'd be grateful if other owners could confirm this is normal, thanks.

I suppose several cameras are on all the time and possibly the computer cannot be shutdown to the level it would be without sentry mode since it has to be looking for possible attacks. Possibly the sentry mode was a goodie thought of after the computing systems were designed which were intended for heavy computational demand needed by autonomous driving?

Moderator note: Moved post to existing thread on this topic

 

[ucmndd]

Normal.

 

[lUtriaNt]

Sentry mode power drain
Sentry Mode Battery Usage
Parking for 7 days with sentry mode
Sentry mode vs long term battery degradation

Mod note: Thanks!