Tesla Sentry Mode: Understanding Its Impact on Battery Life

When it comes to modern electric vehicles (EVs), security features such as Tesla's Sentry Mode have become increasingly important. These high-tech features enhance the safety and security of your vehicle, but they do come at a cost. One key consideration is the impact on battery life, especially when the car is parked and left unattended. In this article, we’ll explore how Sentry Mode affects your Tesla’s range and whether or not it's worth it.

What is Tesla Sentry Mode?

Tesla's Sentry Mode is a security feature designed to monitor the vehicle's surroundings while it is parked. It utilizes the vehicle's cameras and sensors to detect any potential threats or unusual activity. While this feature provides an added layer of security, it does consume electricity, and the amount can vary based on several factors such as duration, environmental conditions, and notifications.

Electricity Consumption of Tesla Sentry Mode

The energy consumption of Sentry Mode can be substantial, especially when left on for extended periods. While the actual amount of electricity used can vary, here are some general guidelines based on the results from various tests and observations:

Duration: The longer Sentry Mode is active, the more energy it consumes. On average, it uses about 1-2 miles of range per hour, depending on the model.

Environmental Conditions: If the vehicle is in a well-lit area, it may use less power compared to a poorly lit area where the cameras have to work harder.

Notifications: If the vehicle detects a potential threat and triggers features like the alarm and lights, it can increase power consumption.

Reliable Measurements of Sentry Mode's Battery Drain

To get a better understanding of how much power Sentry Mode uses, I conducted some experiments using my Tesla Model Y Long Range with SentryCam software version 2021.4.12 and a Sense whole-house power monitor. Here are the results:

Experiment Setup

I selected a time at night when no other power usage in the home was changing to establish a baseline power usage without Tesla charging. The temperature was about 35°F and there was almost no traffic, with nearby animals mainly being rabbits and squirrels.

Results with SentryCam On

As shown in the power monitor results, the baseline home usage was about 1000 watts. The Tesla charging times were about 8900 watts, and subtracting the baseline yields about 7900 watts. The first peak was 9 minutes at 7900 watts, and the second was 15 minutes at 7900 watts. Over a 6.5-hour period, the car charged at approximately 7900 watts for a period of 9 to 15 minutes, averaging about 1185 to 1975 watt-hours.

Using the larger value, the Tesla recharged 1975 watt-hours. Averaging this out over a 6.5-hour period means the standby power usage averages about 300 watts each hour. At this rate, a 75 kWh battery would run for about 125 hours, or 5 days.

Validation of Results

In April 2022, while the weather was moderate, I monitored the car's charge from the app without it being charged. It was losing about 1% of the charge every 2.5 hours with Sentry Mode on. Using this data, the calculation was:

75 kWh × 0.01 / 2.5 hours 0.3 kW or 300 watts

This method aligns with the earlier findings, confirming that Sentry Mode uses about 300 watts per hour on average.

Conclusion

SentryCam results indicate that the average usage is about 300 watts per hour, with a low end of 180. For a Tesla Model Y Long Range with software version 2021.4.12 and a 75 kWh battery, if it starts at 100% charge and is left to run to 20%, it can last about 200 hours or 8.3 days. This means that if you are not plugged in and not driving, you should carefully consider whether to activate Sentry Mode, as it could significantly reduce your battery life.

The cost of running Sentry Mode depends on your location and electricity rates. With an average US electric cost of 0.1319 per kWh as of February 2021, it would cost about $0.95 per day or $346.63 per year. Therefore, it may only be appropriate to turn on Sentry Mode when and where needed, and you can choose to deactivate it when you’re at home or work if not necessary.