Dash cam Hardwire test !

[old4570]

I have a hardwire kit that is advertised to cut power to what ever device @ 11.6 volts . These hardwire kits are generally used to power dash cameras in cars and connected to the cars electrical system . The 11.6 volt cut out is supposed to save the car battery from being run flat when the cams are run in parking mode . So lets check out the claims .

1) Input voltage from 12v to 36v

2) 5v output and 2.1Amp current

3) 11.6 volt cut out to save the battery ...

Test : I ran a action cam to see at what voltage the hardwire kit would cut out . Then I used a dummy load to test current . For power I used a 3s 12.6v Lipo battery . I usually use these to power my electric helicopters , so offer more than enough power for testing .



1) Dummy load @ 1amp setting = 0.92A @ 4.67v

2) Dummy load @ 2 amp setting = 1.66A @ 4.23v

3) Cut out was around 11.31 volts

4) Room temp was 24deg C , hardwire kit ran 36deg C powering a action cam around 0.3A ( Average )



Now keeping in mind that this hardwire kit cost all of $4 ozzi bananas , I was surprised it performed as well as it did . Not sure I would use it to power a cam running parking mode as the voltage cut out is a little on the low side ( 11.3 volts ) , but it certainly seems to provide enough power to feed just about any cam out there ( dashcam ) . I would use this kit to power a cam under normal conditions turning it off with the rest of the electrical system in the car .

Sorry , I was not clear about this ...
I would not connect this hardwire kit @ the battery side ..
I would how ever connect it from a internal power source , internal from the fuse box .

Its like 2AM ATM ...

 

[jokiin]

need to check the output voltage on these, that's where they fail the test, very unstable

 

[Dashmellow]

These kind of cheapo generic Chinese 12V/5V converters are known to fry dash cams. They may work for a time but sooner or later they tend to exhibit voltage spikes and otherwise have poor voltage regulation. Many have learned the hard way that these crappy things are best avoided.

 

[russ331]

These kind of cheapo generic Chinese 12V/5V converters are known to fry dash cams. They may work for a time but sooner or later they tend to exhibit voltage spikes and otherwise have poor voltage regulation. Many have learned the hard way that these crappy things are best avoided.

Sadly, some people don't learn from others experience, won't take good advice, & have to do it the hard way

 

[old4570]

A) I love cheap ...
B) I can't remember whats in my car , but I have 2 cheap chinese hardwire kits .. one is dual output , the other is single output .. They have been in the car for about a year now
C) I purchased this one specifically for testing ..
D) Does 1.66A , and most cams run in the 350mAh region unless charging the battery in which case they may go 700mAh region .
E) Long term ???? , anything can give problems in the long term
F) If this hard wire kit was going to be problematic , it should have reared it's ugly head under the 2A dummy load . ( 7 Watts )
G) I might have to find a more heavy duty dummy load for longer runs .
H) The 3s Lipo has plenty of power , I have ordered a power meter for measuring the load on the battery ( Know whats going in as well as coming out - efficiency )
J) I would trust this one to power a cam . ( But then how many people test before use ? )

Anyhow ! I may have to do another run with a charge doctor in place to see if there are any Voltage spikes .. ( I have ordered a few more charge doctors - one should be decent quality )
Might even do it so the cam video's the charge doctor while running ( I like that ) ..

Just keeping an eye on some 30 year old nicad batteries I am trying to resurrect from the dead .
One is a SAFT 4000mAh 1.2v that gave about 700mAh after charging ..

After some TLC ( careful recharging ) I am currently up to 2000mAh ..
Might get the old girl to light up a few glow plugs after all .
+ I have a dual battery set up that is also about 30 years old .. Currently went over 4000mAh into the battery and still going .. I will have to discharge it to see how much comes out ..
both batteries have sat in my cupboard neglected for 20 or more years . ( Stopped flying control line ) ..
Though the simple answer is just to use some AA NIMH batteries , capable of easily doing 1.5A each , a 3xAA parallel carrier should do 4.5A no problems .. If not 6A with Eneloops .

 

[flip9]

1) Dummy load @ 1amp setting = 0.92A @ 4.67v

2) Dummy load @ 2 amp setting = 1.66A @ 4.23v

If these are the output voltages under load then its awful. I can only imagine how bad the ripple is on this unit. Ripple = HF noise.

The power supply i made for my DSLR using a MP1584 regulator had a stable output voltage at 2A load, even if the input voltage is unstable. Its a fantastic little unit.

https://www.monolithicpower.com/Pro...lators/DC-DCPowerConversion/Converters/MP1584

 

[old4570]

Hmmm PWM , yeah used in drivers for flashlights to improve efficiency and to control output levels .
One of my MM is capable of measuring PWM ..
Cam video was nice and clean .. I had several hours of footage .. ( But then the power came from a Lipo , rather than the cars electrical system which is usually rather noisy )
So how this unit would deal with the electrical noise in a car ??? ( Probably want a Ferrite Core on the power cable to filter out noise made by the cars electrical system )

Just ordered a bigger better dummy load , 15W / 3A variable with a cooling fan ..

 

[thancam]

i lost about 4 mini dashcam because this kind of hardware kit. I still have about 10 hardware kit at home - dont know what to do with these. Cant sell and feel pity if i have to throw away.

 

[old4570]

Hmmmm ....
I just dont know what to think ?
Most cams with batteries , run 4.2v ... ( Fully charged )
So as long as the incoming power ( USB ) is higher than 4.2v , Im not so sure there is an issue there ...
I can see where the voltage , if it went higher than 5v by quite a margin would be problematic .
The static voltage is 5.25v ( Computers USB port is 5v static ) ..
At what voltage does a cam stop functioning ? 3.5v or lower ?
Does the USB power run through the battery / capacitor , or bye pass it ? ( Don't think so )
Obviously the price of this product is an issue , that is undeniable .
Ideally the hardwire kit would want to be between 5v and 4.2v under load ...
No way a cam is going to pull over 1A unless its some huge cam .
Lets see :
Running a cam
@ .25A voltage was 5.12v
@ .3 to .35A ( recording ) voltage is 5.07v

I don't know that .12v is going to kill a cam ..

 

[old4570]

The more I think about it ..
The problem might stem from the cars electrical system ( Voltage spikes )
Rev the engine and voltage increases ( because the alternator is spinning faster )
So how stable is the cars voltage ? And can the hardwire kit deal with any possible issues with a cars electrics ..
Where are you taking power from ?

Seriously if your connecting at the wrong end , then that might explain some issues ..
Your cruising along and the voltage at the battery might be ?? lets call it 13.2 volt , and suddenly you drop two gears , rev the engine out to 6000 rpm
The voltage at the battery might jump to 14 something volts , depending on the car its not unheard of to pull 15 volts ...
So can the hardwire kit deal with such ?
Many of these battery saver kits for Parking mode are meant to connect at the battery side to bye pass the ignition system ..
So yeah ! I can only guess there would possibly be a Valid concern in that regard .

Hmmmm , so possibly more testing :
Alligator clips for battery terminals , XT 60 connector , and rev the engine to see if the power is stable ...
But then I would not connect this at the battery side ...

 

[Dashmellow]

The more I think about it ..
The problem might stem from the cars electrical system ( Voltage spikes )
Rev the engine and voltage increases ( because the alternator is spinning faster )
So how stable is the cars voltage ? And can the hardwire kit deal with any possible issues with a cars electrics ..
Where are you taking power from ?

Seriously if your connecting at the wrong end , then that might explain some issues ..
Your cruising along and the voltage at the battery might be ?? lets call it 13.2 volt , and suddenly you drop two gears , rev the engine out to 6000 rpm
The voltage at the battery might jump to 14 something volts , depending on the car its not unheard of to pull 15 volts ...
So can the hardwire kit deal with such ?
Many of these battery saver kits for Parking mode are meant to connect at the battery side to bye pass the ignition system ..
So yeah ! I can only guess there would possibly be a Valid concern in that regard .

Hmmmm , so possibly more testing :
Alligator clips for battery terminals , XT 60 connector , and rev the engine to see if the power is stable ...
But then I would not connect this at the battery side ...

A high quality 12V/5V converter will have adequate regulation and ripple suppression to output stable clean voltage to your camera regardless of engine speed or what your car's electrical system might be doing.

 

[old4570]

Yeah , this is not a high quality hardwire kit ... This is a $3 USD kit ..
I should have been very clear that I in no way recommend or endorse its use on the battery side of your cars fuse box ...
If one wanted to use it as a power source for parking mode , then find a 12 volt power source that's on 24 / 7 like the power for the door locks or perhaps the power for your car alarm .
It never occurred to me to use it any other way except with a well regulated power source , as well as fused .
Any how , There is some information available now .

( This thread proves to me just how dangerous a little information is )
And how I can some times miss the obvious conclusion some people may make because I left the door open to make that conclusion .

This is a failing on my part ...

 

[flip9]

To answer all your Q's in a nutshell

Cars have a regulator in the alternator which controls the field current. It adjusts the alternator output depending on the electrical load.

The voltage it outputs will still vary around 12-14v, thats why you want a converter that will give a clean stable 5v output.

5v is the nominal voltage for USB circuits. If you give it less than that, funny things can start to happen.

 

[old4570]

To answer all your Q's in a nutshell

Cars have a regulator in the alternator which controls the field current. It adjusts the alternator output depending on the electrical load.

The voltage it outputs will still vary around 12-14v, thats why you want a converter that will give a clean stable 5v output.

5v is the nominal voltage for USB circuits. If you give it less than that, funny things can start to happen.

Yes , and just like anything , it may or may not work as well as one would like .. Especially if the car is an older model and has a few hundred thousand kilometers on the clock .
If you drive nothing but the best German Engineering , then I would assume that the alternator output to be more stable and cleaner ( RF ) .
Still I would not connect to the other side of the fuse box , especially as I don't drive fine German engineering .. ( I drive locally made rubbish )
In fact all the local car companies are closing their doors as they could not make a decent car since the early 70's . ( Turning point for the car industry world wide )

 

[old4570]

Now I need to know !
How low can you go ?

What I mean by that is voltage to the cam ...
At what voltage level does a cam kick up a fuss ?
Ordered a variable voltage power supply to find out .

Input Voltage: 6V-40V
Output Voltage: 0V-36V
Output Current: 0A-3A
Voltage Regulation: 0.01V
Current Regulation: 0.001A

 

[flip9]

Set the output voltage to 5.2v and it should not drop under 5v at 1A load.

Get a multimeter with a min/max feature and run a dummy load for a day to see if theres any spikes.

Test with different input voltages (9-24v) as well under 1A load and see if the output voltage stays the same.

 

[JharwinBlack]

@old4570 man I love how you see all things in this manner. I love to shop at ebay too because the price point it doesnt matter if it came from china or anywhere else in the world. My same bottom line is, do hard testing first like what you did before you put it in the real device you want to power it up. Kudos my friend!

PS, im into all those flying things too. Fpv long range rc

 

[old4570]

@old4570 man I love how you see all things in this manner. I love to shop at ebay too because the price point it doesnt matter if it came from china or anywhere else in the world. My same bottom line is, do hard testing first like what you did before you put it in the real device you want to power it up. Kudos my friend!

PS, im into all those flying things too. Fpv long range rc

Wow Thanks ..