There are 2 types of dash cams.... Capacitor based and non-capacitor based (built-in battery).
But for WHATEVER reason, there's literally only one brand that offers the capacitor based dash cam. It's from Aukey.
The benefits of the capacitor is that the power is fed from your vehicle via your fuses using a hardware fuse kit or your cigarette lighter port via USB. Additionally, the biggest concern I have with built-in batteries is fluctuating temperatures, especially when it comes to heat. Fluctuating temperatures diminish the life of the battery and with hot temperatures, it puts the dash cam at risk for failure.
The benefits of the non-capacitor versions is that since there's a built-in battery, some of the dash cams have 'motion detection' to turn on even when your car's off. The downside? The battery and risk due to fluctuating temperatures in the car and direct sunlight to the device.
For the 2 Aukey dash cams I recommend, it's either he 'DR002' model or the 'DR001' model. At a sale, you can grab these for $50. Then a Class 10 microSD card (32gb works for your purposes) typically for $10-15.
Aukey DR002: [
slickdeals.net]
Aukey DR01: [
slickdeals.net]
The prices above ($50) are currently not available, but come around ever so often if you're willing to wait.
For hardwiring your dash cam, a kit like this works: [
www.amazon.com]
Only details that may change your needs for the hardwiring depends on the kind of fuses your vehicle has (low-profile, mini, etc.).
I tried to condense the information as much as possible, but hope this helps!
My setup in my vehicle has the Aukey DR-01 model ALWAYS mounted with wires hidden and hardwired to my fuse box. So when I turn on my car, my dash cam turns on. I eventually plan to add a second one of these to the rear windshield for additional documentation.
Shopping the Greater Denver Area, Colorado Springs and in-between in Colorado. 33 year old male and willing to travel!