Have you learned about Tesla’s “sentry mode”? When sentry mode is enabled, it uses a few surrounding cameras to monitor activities happening in the vicinity of the car when left unattended; it records collisions, strikes, thefts/burglary, or any incidents that potentially damage the vehicles.
It sounds like a so simple function that every car should be able to have it; the reason why Tesla is the only auto brand that rolls out this type of safeguard use is -- power consumption. High definition cameras using advanced compression technologies on average consumes 0.5A from a 5V power supply; this is equal to a 2.5W power consumption. A 12V lead-acid car battery has a capacity of 40 to 60 Ampere-hour. If we convert its unit to energy capacity, it equals 0.48 to 0.72 kW-hour. Let’s say the allowable discharge is 10% of a battery maximum capacity; thus, with a continuously active camera, a normal car battery will be over discharged after 19-29 hours. Needless to say if 4 cameras are used to monitor the four directions of a car, it lasts only 4.8-7.2 hours, which is too short for monitoring.
Featuring different battery equipment, Tesla vehicles have a 50-100Kw-hour capacity. Under the same condition, monitoring by a camera can lasts 2000-4000 hours. Even using 4 cameras, it can be active up to 500-1000 hours -- about 20-40 days. No wonder Tesla or other electric vehicles (EV) which carry large battery capacity can come up with such a convenient function.
Are EVs the only option to go for if we really want this feature? Not exactly. The high power consumption problem can be solved by technology innovation -- radar sensors. Terasilic provides customers 24GHz radar AiM (antenna-in-module), which is the smallest 24GHz radar sensor with the lowest power consumption in the industry. It provides multi-targets detection and tracking within 10 meters range while consuming only less than 5mW. This equals to 0.2% of the power budget for an operating camera. With Terasilic’s latest radar sensors on dash cams or security camera systems, the cameras can be kept in sleep modes most of the time, and the recording can be activated immediately as soon as the radar sensor detects potential threats. In these radar-assisted camera monitoring systems, the average power consumption is significantly reduced. People driving gasoline cars therefore also enjoy the protection and convenience provided by continuous monitoring cameras like those installed in Tesla or other EVs.