Given the proliferation of fraud, accidents and sheer craziness on the roads today, having a dashcam in your vehicle is, at the very least, a wise investment. These compact camera systems capture video of everything that happens while you drive, in the event you need to share information with the authorities or on social media. Many dashcam systems have a parking mode feature that allows the camera to continue capturing information even when the ignition is turned off. Let’s look at how this feature works and consider its benefits and limitations.
What Is Parking Mode?
Parking mode on modern dashcams is activated automatically when the vehicle remains stationary for a few minutes, or the ignition is turned off. At this time, the dashcam stops storing video on the microSD card but continues to monitor the signal from the image sensor. When there is a significant change in the image content, as would happen when someone steps into the field of vision or a vehicle drives by, the dashcam will store a video of what’s happening. The concept of parking mode is to allow “motion only” videos to be stored while the vehicle is parked. This functionality is similar to security camera systems that are activated by motion. For example, the camera should record what happens if someone approaches your vehicle to vandalize it, tamper with it or try to steal it.
The advantage of motion-activated video recording is that the files on the microSD card should contain only important information and not hours of the same fixed scene. For example, suppose you’ve backed your vehicle into your driveway. In that case, you will likely have videos of the neighbors walking their dogs or people driving home from work, along with anything that might identify someone with ulterior motives toward your car or truck.
Drawbacks of Parking Mode
A dashcam is a small computer. It has a microprocessor, memory and storage. All computers consume moderate amounts of electricity to operate. When the engine in your vehicle isn’t running, that electrical energy needs to come from the battery. Most dashcams consume between 200 and 500 milliamps of current while in operation.
It should come as no surprise that the battery in your vehicle is limited in terms of the energy it can store. When the vehicle was designed, the battery size was chosen to provide adequate capacity without being so oversized that it represented a weight penalty. If you have an older vehicle, the only circuit that might draw power from the battery when the ignition is off would be the clock in the dash or the radio. These devices might draw a few milliamps. Modern vehicles include many more features and consume a lot more energy. If you have a keyless entry system, the vehicle will have a radio receiver integrated into the security or body control module. Many premium vehicles have telematics systems that use cellular data communication. If a smartphone app is available to remote start or unlock your vehicle, then this radio transceiver will be drawing current while the vehicle is turned off.
How long do these “background” systems take to deplete a modern car battery? Most modern vehicles draw 20 to 30 milliamps of current when fully asleep. If you have a keyless entry system, this amount increases. Let’s use 40 milliamps as a nominal value. The average new car has a group 124 car battery, or at least something similar. Luxury vehicles with more technology might have a larger battery, while economy cars might have a smaller one. When fully charged, these batteries typically have a reserve capacity of 65 to 80 amp-hours. Though most batteries are rarely fully charged, for this example, let’s consider a battery with 70 amp-hours of capacity. If we divide the battery capacity by the draw, we get the hours the battery should last before depleting. In this example, we should be able to leave the vehicle unattended and unused for about 73 days. I’d suggest that starting the vehicle after sitting that long will be VERY difficult. Nevertheless, that’s the math with a 40-milliamp draw.
What happens if we add a dashcam with 350 milliamps of draw to the battery? Suddenly, we only have seven and a half days of capacity. If your vehicle’s battery wasn’t fully charged using an external battery charger, I suggest you’d be lucky to get half of these times and still be able to start the vehicle.
Automatic Turn-Off Features
When shopping for a dashcam with plans to use the parking mode feature, look for one that a professional installer can hard-wire into your vehicle. These dashcams will have a power and accessory wire rather than a cigarette lighter plug. Second, make sure the camera has an adjustable low-voltage cut-off feature. Your installer can specify the battery voltage at which the camera will shut down and prevent your vehicle’s battery from being drained, so you can’t start it without a boost. Lastly, ask them to set this voltage relatively high. I’d suggest that 12.3 volts should leave you enough reserve to start the vehicle. The absolute voltage depends on the condition of your battery and how often you drive the vehicle.
Charge Your Car Battery Properly
If you drain the battery in your vehicle, it MUST be recharged properly. Running the engine for 15 minutes or going for a short drive will NOT put any significant charge back into the battery. Instead, you should connect an external electronic charger to the battery for at least 10 to 15 hours and let it absorb energy slowly. Forcing large amounts of current into a battery quickly only causes unwanted heat that could damage the lead plates and reduce the energy storage capacity.
Alternate Dashcam Parking Mode Technologies
A few dashcam manufacturers have switched from image-sensor-based parking mode monitoring to solutions like radar. For example, the Momento M7 camera we reviewed in 2022 has a feature called Eco Mode. When activated, the camera uses a built-in ultrasonic transceiver to detect motion in front of the vehicle when in parking mode. The benefit of Eco Mode is that the camera only consumes about 32 milliamps of current while monitoring. Yes, the consumption increases while recording, but that only lasts for a minute or so. At 32 milliamps, our 70 amp-hour car battery can last almost 27 days. Call it 20 days, given the assumption it will make several recordings and draw some extra energy. The takeaway is that a camera like this will strain your vehicle’s battery less.
Protect Your Vehicle Intelligently
A dashcam with a parking mode feature is a wise investment if you’re concerned about vandalism or catalytic converter theft. Talk with the product specialists at a local specialty mobile enhancement retailer. They can tell you which cameras they offer include the parking mode feature and discuss how much current each model consumes so you’ll know how long your battery will last.
