Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Additional Power Supply for car Dash Cam 1

Status
Not open for further replies.

loftus49

Computer
Aug 7, 2024
4
0
0
US
I have an Engineering issue to resolve.

I have a Car Dash Cam that has a "24hour Parking Mode". It comes on automatically when the car is turned off and there is an inline device that will stop it (preventing battery drain) when the battery discharges to a pre-set level (e.g. 12.3 volts, 12.8 volts, etc.)

Also, you can adjust the frame rate which will also affect power consumption.

The unit is wired to a switched fuse (power on only while the engine is running) for video while driving and it is also wired to a constant power fuse (direct battery power when the engine is off) for the parking mode. The input to the unit itself is 5v / 1 amp.

However, with this arrangement, it appears that you can only run the Parking Mode for about 12-24 hours before it switches off due to battery drain.

How can I run the Parking Mode for 4 or 5 days?

Additional battery pack? How much battery pack and what form? If so, how to wire it so that it can recharge once engine is running again.

The DashCam company's engineering group says that it draws about 1.3 watts per hour from the 12 volt battery. So theoretically that would be 31.2 watt hours per day or 124.8 watt hours for the four days.

What power supply should I get and how should I configure with the least footprint if this is at all feasible.
 
Replies continue below

Recommended for you

A surprisingly big one.

These guys make some really nice bits of kit, but even the smallest is not cheap.
but they might shut down on such a small power draw.

Or probably just one of these?
125 Wh at 5V is 25,000 mAh

But you just run it like a small UPS. Feed in from the switched live recharges it and a connection out.

How you know when its fully charged is another thing though.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
To recap:
The DashCam company's engineering group says that it draws about 1.3 watts per hour from the 12v battery. So theoretically that would be 31.2 watt hours per day or 124.8 watt hours for the four days.

125 Wh at 5V is 25,000 mAh
mAh = 1000 × Wh ÷ V

Again, theoretically, a power supply providing 40,000 mAh should suffice for 4 days.

I could remove the wired USB power cord from the DashCam and plug in the power supply's USB to run "Parking Mode".

I could then reconnect the "switched" power hardwired from the 12v battery to run the Dash Cam while driving. And use the USB connection from the cigarette lighter to re-charge the power supply while driving.

Or I'm way off base here?
 
The power bank has two connectors at least ,power in and power out. Do I think they don't like doing both at the same time so yes, some sort of relay to change power from bank to car when you start up would seem to be a good idea.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
OP,
The DashCam company's engineering group says that it draws about 1.3 watts per hour
Are you sure this is watt per hour and not watt hour or just watt? If something is "drawing" something that implies a rate, e.i. Joules per second or Watt. Please confirm the actual rate that the piece of equipment uses power.
 
Good point - so many peolpe just can't understand the difference between power and energy.

I took it as 1.3W. So would 1.3Whr every hour... at 12V supposedly.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
I assumed WHr per Hr as well from the first post, but OP doubled down on it, so I thought I'd confirm. Based on OP's description there are different modes and frame rates associated with different levels of power consumption.
What rates should be used for sizing?
Are these rates constant, average, minimum, maximum?
Of course, you can size for maximum but if your only goal is 4 days, it may use less depending. You could run a test, set it in the mode you want, power it off of a fully charged battery, then check the battery charge after 12 or 24hrs to determine power consumption or at the very least, observe the actual amp draw with an ammeter. Manufacture claims are not always the best source of design data.
 
The parking thing takes one picture per minute I think so power usage should be pretty low.

Agree that actual data is far better than vendor stuff.

Just watch that sometimes the power supplies shutdown after so many hours when there is only a trickle of power going out or only going out every 5 minutes or so.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
An alternative consideration, does this camera have motion detection in Parking Mode? This could be a source of excessive power consumption. I would suggest a true usage test to determine, based on a typical parking location what actual power consumption is. For battery sizing, consider useable power, not just battery capacity. Depending on battery type and voltage, it's usable power may only be 20%-90% of battery capacity. Also consider temperature is going to affect the battery as well and being in an unconditioned car may have unintended consequences. Charge/discharge cycles and degradation could be a factor as well. As far as actual usage and capacity, consider a reasonable safety factor, something like 50% or select the next common size larger when determining battery size.
 
Heavyside1925 brings up another consideration - it really should be motion-activated. That is a very common technology for cameras, and a how they are able to operate for days or weeks on much less energy than what you're trying to accommodate. If your dash-cam doesn't have the ability to run as a motion-activated camera in parking mode, you should really consider getting a different dash-cam.

Besides the energy consumption, at 1 picture per minute, in 4 days it's going to record nearly 6000 pictures, and 99+% of those pictures are going show the same thing (nothing going on), it seems unnecessary and arduous to take and store that many pictures of nothing happening, not to mention trying to sort through them and find the ones you want if something does happen during that 4 days, if you don't know when it happened.
 
hat it does is shoot one frame but then links it into a single video file. Or at least that's what mine said it did.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Trail cameras use a PIR, a passive infrared sensor, as a motion detector to wake the camera. PIRs require some power, but not as much as the camera CPU does.

Camera sensor motion detection continuously takes frames, comparing each to some average of the previous ones and starts recording when there is some percentage change in the image. This saves storage over simply recording continuously, but requires power to the sensor and the CPU. I suppose the system could be designed to inspect only even rows or multiples of 8 or 16 and do motion detection on those to lower the CPU power requirements.

I think there are some car cameras that also include motion sensors to wake the camera CPU if the car is bumped.
 
Me: What is the draw per hour of the DashCam in parking mode at various frame rates?

Support: Hi, yes, they said it's about 1.3w

Me: How long would a 40000mah Power Bank power the dash cam in "Parking Mode" ?

Support: Hi, it's about 4-5 days.


It's the V100 from - a Chinese company and hard to find a technical spec on it. I also added the 256GB SD Card. The most specs I found were on Amazon where it was purchased:

Product information
Product Dimensions 1 x 1.5 x 3.2 inches
Item Weight 1.13 ounces
ASIN B0D2H2XB78
Item model number 2.5K Dash Cam
Customer Reviews 4.5 4.5 out of 5 stars 373 ratings

4.5 out of 5 stars
Best Sellers Rank #1,010 in Electronics (See Top 100 in Electronics)
#8 in Car On-Dash Mounted Cameras
Connectivity technologies Wi-Fi
Special features QHD 2560*1440P 30fps; Type-C Port, 32GB SD Card Included; Compact Mini Design, (Email: support@customerafter-sales.com), Built‒in WiFi and APP Control; 24H Parking Monitor(Additional Hardwire Kit Needed), G-Sensor + Loop Recording; Voice Alert
Other display features Wireless
Color Black
Whats in the box 2 * Electrostatic Sticker, 1 * Car Charger(11.5ft), 1 * Spare 3M Adhesive Pad, 1 * V100 dash cam, 1 * User Manual + 1 * Easy Pry Tool
Manufacturer E-YEEGER
Country of Origin China
Date First Available May 12, 2024
Warranty & Support
Product Warranty: For warranty information about this product, please click here


I purchased a 40,000 mAh power bank. At this point, I plan to install this weekend - then test. Thank all of you so much for your involvement and commentary.
 
Status
Not open for further replies.
Back
Top