Tesla SentryCam power usage

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What amount of extra power is used by a Tesla’s Sentry Mode?

I was curious myself, so I measured my Tesla Model Y (Long Range), with SentryCam (Software 2021.4.12) on with my Sense whole house power monitor. Below is an expanded section of my power usage.

TeslaSentryCamPowerUsage
TeslaSentryCamPowerUsage1604×616 72.9 KB

Experiment Setup
A time at night was selected when no other power usage in the home was changing to establish a baseline power usage without Tesla charging. This allows seeing just the additional amount of the Tesla charging by subtracting out the baseline.

The temperature at night was about 35F degrees. There was almost no traffic (certainly not within 30 feet of the car), and the nearby animals are mostly rabbits and squirrels, if that makes any difference to the usage.

SentryCam On Results
As can be seen on the power monitor results shown at the top, the average usage baseline for the home is about 1000 watts. The 2 orange peaks shown, which are the Tesla charging times, are about 8900 watts. Subtracting out the baseline yields about 7900 watts for the peaks. So the 1st peak is 9 minutes at 7900 watts and the second is 15 minutes at 7900 watts. The time spacing between the charging times was a consistent 6.5 hours over many days with Tesla sitting idle.

So the car is charging at approximately 7900 watts for a period of 9 to 15 minutes, or about 1185 to 1975 watt hours every 6.5 hours.

Using the larger one, the Tesla recharged 1975 watt hours. Averaging that out over 6.5 hours frequency means the standby power usage averages, at most, about 300 watts each hour. That means it uses about 0.4% of the 75 kwh Model Y Long Range per hour. If I left it at a parking facility at 70% charge and let it run to 20% charge, it would run for about 125 hours or 5 days

SentryCam Off Results
After running with SentryCam off overnight and outdoor night temperatures being the same, there was no charging of the car at all.

Conclusion
SentryCam is resulting in about an average 300 watts per hour usage (with a low end of 180), and the Tesla Model Y Long range (as of software version 2021.4.12 and in middle of March 2021), charges the car every 6.5 hours (probably due to some thresholds of charge replenish internal settings).

For an average US electric cost of $0.1319 per kWh as of February 2021, that means it would be costing $0.95 per day to run, or $346.63 per year when idle.

So depending upon where you live, and what kind of damage to your car you might experience, it may only be appropriate to turn on SentryCam where and when needed.

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Thanks for the analysis. This agrees with the guidance to turn off sentry mode when parking for extended times unplugged like at an airport parking lot.

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Incredible analysis there. Nice work.

FWIW, the Tesla community uses a “rough” estimate of 1 mph to run the Sentry Cam. And, while for some 300w is a bit more than the average mile, at 35 degrees, it’s probably pretty close!

Still, 300w/h does seem a bit high to run a simple camera and log it to a flashdrive (unless you’re using a rotating drive) so we all know it’s a lot of overhead running the full infotainment system etc as well. Perhaps we’ll see an improvement in V11, as it’s clear there is plenty of room to throttle down the CPU for such a simple task.

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Thank you!

I don’t think the temperature has any relation to the number of watts the Sentry Cam uses. And I am using a M.2 NVMe SSD drive.

But I agree it seems a bit much, and think they could come up with a less power hungry solution.

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SentryMode itself doesn’t use any extra energy vs the car just sitting at idle. I can say this with confidence from 2.5 years of continuous data logging of my 2018 Tesla Model 3. When a Model 3 or Y is parked an in an idle state, all of the cars electronics are powered. All 8 Cameras, the Autopilot Computer, the MCU, the Wireless Radios (WiFI, Cellular, Bluetooth) are energized and functioning. Sentry Mode actively processes 4 of the 8 cameras for Sentry Mode (1 of 3 front cameras, the rear camera, and each front fender camera). In addition there are a few other sensors involved that pick up vibration and infer things like glass breakage. This data is then optionally written to the external USB storage device, AND/OR the onboard storage in the case of a triggered SentryMode Alarm.

While all of this is happening, the high voltage battery system is active and powering the cars functions indirectly via the 12V battery and electrical system. The High Voltage pack maintains the 12v battery via a DC-DC inverter and the 12V battery then powers the cars electronics. This is part of the issue that Tesla experiences with their 12V batteries. There is currently no way to power the cars electronics without all of the energy running through the 12V battery. Over time this continual usage degrades the 12V battery to the point where it requires replacement. This is different than a traditional ICE where the alternator can actively provide power to the 12V system and the 12V battery doesn’t constantly drain/charge in the same way. A good comparison is using a wireless charging pad to charge your cell phone vs using a USB cable. When using a regular charging cable on your phone there is a circuit that can directly power your phones electronics and bypass or limit the amount of energy that is sourced from the phones battery. When you use wireless charging, the energy always has to come from the battery pack and this increases wear on the phones battery.

The energy cost to keep a Model 3 or Y in the idle state is right around 300W/hr. This is down from approx 700W/hr and this was improved via software update sometime in early 2019 if I recall. Whether Sentry Mode is running or if it is turned off and the car is just idle due to say a third party monitoring tool/service is constantly polling the Tesla API to poll for data and preventing a sleep state, the energy drain is the same 300W/hr When SentryMode is not activated the car is allowed to go into a sleep state. The sleep state physically decouples the high voltage battery pack from the car. When the car enters or exits sleep you will hear the high voltage circuit flip into the appropriate closed or open state. When this happens the car goes into a minimum power usage mode. Only the Bluetooth radios, the RFID reader, and a minimum cellular connection is maintained. When this state is reached, battery drain is very close to zero.

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I can’t speak for your vehicles, but my 2021 Tesla Model Y charges for a few minutes at 32 amps 240 volts about every 36 hours with SentryCam off, vs every 6.5 hours as I show in my example with SentryCam on.

Using SentryCam would be an additional 2,500 Kwh each year less the time you are driving. That would remove a lot of the gas savings you save each year.

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If your car is sleeping, it should go MUCH longer than 36 hours before waking and topping off the charge. Are you using any third party services such as TeslaScope, Teslafi, Watch App for Tesla, or other third party services to monitor/control your Tesla besides the official app? If so, those access the unofficial Tesla API and may be waking your car up from a sleep state or preventing it from sleeping all together. Both my 2018 Model 3 and 2020 Model Y can go MUCH longer than 36 hours between charging top offs. I have left my model 3 parked an in a sleep state for 2 weeks and not have it wak up to top off the charge once in that time.

Back to the point of Sentry Mode, it doesn’t use any extra energy vs an idle state. An idle state consumes approx 300 watts at any given time. Sleep mode uses very very little energy as the high voltage system is disconnected from the car during sleep.