The majority of dash cams come with a power cord that plugs into your car’s “cigarette lighter” style power outlet. Here's an example:

This power outlet receives “switched” power from your vehicle’s electrical system. This means that the dash cam will turn on when the car engine is turned on and the dash cam will turn off when the engine is off.

Dash cams typically just turn on and off with the engine, automatically recording video while you drive. Dash cams can also be set up to stay on and keep recording even when the car is parked and the engine is off, thereby functioning as a surveillance camera system while you're away from your vehicle. This feature goes by a few names depending on the brand; most brands like BlackVue refer to this feature as “parking mode” while some like Garmin call it “parking guard" or another term.

Since dash cams don't utilize large built-in batteries, external power must somehow be supplied to the dash cam when the engine is turned off. This can be done by leaving the dash cam plugged in to an "always on" (a.k.a. constant power) outlet in the vehicle, if one is available. However, a majority of vehicles do not have an outlet that is powered on all the time, since this is risky as it could potentially drain your car battery.

To preserve the health of your car battery, we recommend that dash cam owners who want to use their dash cam as a surveillance camera system opt for a smart power device like the Power Magic Pro.

Most Thinkware dash cams have parking mode low-voltage cutoff protection built-in to the camera itself, so no external control module is needed which is quite nice.

BlackVue’s Power Magic Pro Battery Discharge Prevention Module is a smart device which will safely supply power to your BlackVue or other brand dash cam while your vehicle engine is turned off. The Power Magic Pro was designed to monitor your car battery voltage and will turn the camera off if the car battery reaches the time or voltage safety threshold that you have specified.

So now you've solved the problem of safely supplying power to the dash cam when the engine is not running, it's time to discuss how the camera functions in "parking mode". If recording while parked is important to you, it's best to select a dash cam that features an “intelligent” parking mode and/or motion detection.

A dashcam with intelligent parking mode automatically detects when the vehicle is parked, and changes its behavior accordingly. High quality brands such as BlackVue and Thinkware, for example, in parking mode do not continuously record hours of useless footage. Instead, what happens is the dash cam continuously "watches" from the camera lens(es) but nothing is saved to the memory card unless someone or something triggers the motion detection (e.g. a person walking into the field of view) or the built-in G-sensor is activated (e.g. by an impact to the vehicle).

A nice feature of the BlackVue dash cams is that they actually buffer their parking mode video, meaning 5 seconds of video *before* an impact to the vehicle will be preserved on the memory card, as well as footage of the actual impact itself. Many other dashcams do not have this buffer functionality and only start recording at the moment of impact, rather than also capturing the events that led up to the impact.

In general, dash cams consume very small amounts of power, so a healthy car battery in a vehicle that is driven regularly will have no problem supplying power to a dash cam for many hours or even days before reaching a safety cutoff threshold.

To give you a specific example, the average power consumption of the dual lens BlackVue DR750S-2CH dash cam is between 300 and 350 milliamps (3.6-4.2 watts @ 12v). A single-lens dash cam like the DR750S-1CH consumes even less power: between 200-250 mA (2.4-3 watts @ 12v). So, your dash cam is drawing about as much power as a 3-4 watt light bulb would (like the bulb in the flashlight below):

No, you don’t! Devices like the Power Magic Pro or DOD DP4 are designed to monitor your car’s battery level; even if it is several years old. If your battery voltage drops too low, the device will turn the dash cam off so that you never return to your car to find that you have a dead battery.

Your vehicle uses electrical circuits, just like the ones in your house. These circuits supply power to the electrical components located throughout your car, like your headlights, your radio, and your door locks.

In modern cars, there are generally two types of circuits that run through the vehicle: circuits that are live all the time and circuits that are only live when the engine is running. A circuit that is live or hot all the time means that it constantly receives power from the car battery, even when your car is parked and the engine is turned off. Cold circuits, or circuits that are only live when the engine is running are also known as switched circuits.

If you're installing a Power Magic Pro yourself, you'll need to know how to identify these constant and switched circuits in your vehicle. We've created a video to help you out!

We recommend that our customers set their Power Magic Pro to cut off at 12.0v. and infinity time. We have found that 12.5v is a bit too high for most vehicles.

We also recommend infinity for the time value, that way the dash cam will stay on as long as possible, only turning off once the voltage threshold has been reached. The Power Magic Pro will still turn off based on voltage even when set to infinity time as shown below:

We have found that the Power Magic Pro is a better fit for the vast majority of our customers, due to the lower cost of the device and relative strength/robustness of existing vehicle batteries and electrical/charging systems.

The B-112 / B-124X Battery Pack is a sizable power pack that is designed to plug in to your car's cigarette lighter power outlet. This battery pack supplies power to your dash cam via the high-quality Lithium Iron Phosphate battery that is built-in to the battery pack unit. BlackVue's B-112 / B-124X battery pack can provide power to your BlackVue dash cam for up to 12 hours after 1 hour of rapid charging. The B-112 / B-124X is a plug-and-play setup; there’s no tapping into the fuse box needed with this power accessory.

Keep in mind that if you use your vehicle to commute distances less than one hour, you may not be able to sufficiently charge the B-112 / B-124X battery pack and have a guaranteed battery power storage to consistently record in parking mode. For these reasons, in general we recommend the Power Magic Pro over the B-112 / B-124X.

*** update: B-124X now replaced with B-130X ***

If you return to your vehicle after some time and notice the dash cam is off when you expected it to be recording in parking mode, you can look at the green LED light on the Power Magic Pro box. If the light is off, this means that the voltage has been sensed to be below the threshold, so the camera has been turned off to preserve the car battery.

When you start your engine, the Power Magic Pro green LED should turn back on, and the dash cam should power up as well. If this occurs, you’ll know the Power Magic Pro was doing it’s job of safely powering the camera system for as long as possible.

No. In this case, the Power Magic Pro takes the place of the installation kit, so you will only need to use a Power Magic Pro. To clarify, the Universal Dash Cam Quick Installation Kit is designed to connect to a switched fuse in your fuse box, which means that it will power on and off with your engine. The Universal Dash Cam Quick Installation Kit will not allow you to utilize parking mode, and we don’t recommend this kit for BlackVue dash cams.

Most likely, what is happening is that when your vehicle starts, the battery is temporarily dipping below the 12.5v threshold (as the engine is cranking). This may be causing the Power Magic Pro to turn off. We suggest that dash cam owners set the dip switches of their Power Magic Pro to 12.0v and infinity time. This is still a safe range to prevent draining your car’s battery.

If you replace a BlackVue dash cam for a newer model, you can use the existing wiring with your Power Magic Pro and you will not need to reinstall it. With that being said, you may need to replace the front windshield mount, as the mount sizes vary from model to model.

Have you double checked that your voltage switches are set to 12.0 or 12.5v? Is your timer switch set to infinity?

We've created a troubleshooting guide to go over the most frequent troubleshooting questions to ensure that your Power Magic Pro has been installed correctly.

Click on the image below to open the troubleshooting guide in a new window.

First, we recommend ensuring your firmware is up to date. BlackVue continually releases new firmware versions that are designed to address common problems, so it’s always a good idea to upgrade to the latest versions when those become available. See BlackVue's download page for more information on this topic.

Second, ensure your setting for “Automatic parking mode” is set to “On”. If this value is set to off, the dash cam will record in “Normal Mode” at all times, rather than automatically switching to parking mode when the vehicle has been stationary for some time.

Third, it may help to adjust the “Normal Mode” G-Sensor settings of your dash cam. Since most BlackVue dash cams take into account the built-in G-Sensor readings to determine when to switch to parking mode, if your sensitivity is set too high, the dash cam may be detecting vibrations from vehicles driving by or other tiny vibrations which could be preventing the dash cam from entering parking mode.