DAP
Well-Known Member
- Joined
- Sep 5, 2014
- Messages
- 544
- Reaction score
- 280
- Location
- California
- Country
- United States
- Dash Cam
- Two Viofo 129 PRO cameras and a Tesla Model 3 4 Channel
I just measured the power of two different dash cams. One draws 2W, the other 1.6W (the 1.6W is an A119, other one is a bit older).
Lets go with the 2W one to be conservative.
Assuming 80% efficiency of the voltage regulator in the cigarette lighter plug, we get 2.5W drawn from the battery.
Assuming 12V, you are drawing 208 mA from the battery.
My cars battery has 100 minutes of reserve capacity. This is defined as how long can you draw 25A from the battery before its voltage drops below 10.5V
We will assume this is a good estimate of the ampere hour capacity of the battery (since this specification is not given), and we get 41.6 AH.
Lets assume we don't want to drop the battery below 50% charge (so we can still start the car at the end of this), and we get 100 hours, or 8.3 days.
Note also that the battery is driving a bunch of other electronics while the car is parked, so it will actually drain a bit faster, but it is probably safe to leave the camera running over a weekend.
Lets go with the 2W one to be conservative.
Assuming 80% efficiency of the voltage regulator in the cigarette lighter plug, we get 2.5W drawn from the battery.
Assuming 12V, you are drawing 208 mA from the battery.
My cars battery has 100 minutes of reserve capacity. This is defined as how long can you draw 25A from the battery before its voltage drops below 10.5V
We will assume this is a good estimate of the ampere hour capacity of the battery (since this specification is not given), and we get 41.6 AH.
Lets assume we don't want to drop the battery below 50% charge (so we can still start the car at the end of this), and we get 100 hours, or 8.3 days.
Note also that the battery is driving a bunch of other electronics while the car is parked, so it will actually drain a bit faster, but it is probably safe to leave the camera running over a weekend.