Hardwire kit discharging battery

cool_kuba

Member
Joined
Sep 3, 2018
Messages
47
Reaction score
8
Country
Poland
Looks like I am having never ending string of problems with Mini 0906 camera. I didn't manage to fix TPMS interference of rear camera yet and now I couldn't start my car after leaving my car parked for two weeks.
I measured and hardwire kit is drawing ~20mA in off state versus ~300mA in on state.
I have Hardwire kit for 0906 from Aliexpress https://www.aliexpress.com/item/Universal-Micro-USB-Hardwire-Fuse-Kit-low-voltage-protection-12V-to-5V-Power-Adapter-Cable-for/32835298362.html
Did anybody have similar problems with this kind of hardwire kits?
Could you recommend some 0906 compatible hardwire kit with lower off current? (I read in the internet that normal battery protection have off current in range of 1mA)
 
OP
C

cool_kuba

Member
Joined
Sep 3, 2018
Messages
47
Reaction score
8
Country
Poland
I did some measurements in the car and I get
avreage current with camera off: 35.4mA
average current with camera disconnected: 21.7mA (This is just standby of the car)
I am guessing now that draw from camera was just one factor, it might be the time to replace my battery .

Anyhow 14mA still seems too much for off state.
Does anybody know how much power this hardwire kits usually draw from battery in off state?
Did anybody measure 0906 kit? (I am wandering if I have some broken unit it is cutting power correcty though)
 

tinman

Active Member
Joined
Feb 25, 2014
Messages
103
Reaction score
48
Country
United States
I did a whole bunch of current measurement on the hardwire kit a long time ago.

 
OP
C

cool_kuba

Member
Joined
Sep 3, 2018
Messages
47
Reaction score
8
Country
Poland
tinman have you try to measure the current draw when it drops below threshold?
I think I had quite similar results when running and parking mode also not too big difference.
 

tinman

Active Member
Joined
Feb 25, 2014
Messages
103
Reaction score
48
Country
United States
Unfortunately I don't have the hardwire kit any more. It was having issues which made it undesirable to use in my cars.

But, since the hardwire kit is designed to power off the CAM when the battery drop below a certain voltage level, when that occurs, the CAM should not be receiving any power, thus the only current draw will be the hardwire kit in a no-load condition. Base on this, and assuming the DC-DC regulator used was designed for low current draw under no-load condition, the current draw would be then in the uA range or in the low mA range.

With all that said, I did do a quick measurement of that a while ago:
 

Rayman.Chan

Well-Known Member
Manufacturer
Joined
Oct 7, 2013
Messages
1,374
Reaction score
885
Location
Shenzhen
Country
China
Dash Cam
mini0806, mini0806S, mini0903/0905, mini0906, mini0808
the no load current draw most work on the MCU, MCU power source and voltage detection circuit which will not shut down.
 
OP
C

cool_kuba

Member
Joined
Sep 3, 2018
Messages
47
Reaction score
8
Country
Poland
@Rayman.Chan Do you think it is possible to lower off current drawn?
Could you offer version with MOSFET and op-amp?
I read in the internet that people make under voltage protection which uses ~1mA in off state
Current drawn from battery shouldn't exceed 25mA which will be very hard if hardwire kit is using 15mA itself
 
Last edited:

tinman

Active Member
Joined
Feb 25, 2014
Messages
103
Reaction score
48
Country
United States
When you say MOSFET and op-amp, what is that for? Why would you want an additional op-amp in the circuit? That would just be another additional IC to keep in bias condition.

The under voltage protection usually means there is an external monitoring which will shut down everything, which is why it's possible to get the ~1mA draw.

As for the 15mA you are measuring (a 300mW draw assuming a 12V supply), that does seem high when compare to the DC-DC regulator spec. under no-load condition (3mA), which leads me to believe there may be a measurement issue here. Are you measuring the current using a bench supply or right inside the car? How is the current being measure? From an amp meter?
 

Similar threads


Top