Cobra CDR 835, awesome camera but battery died, how to replace

dainova

New Member
Joined
Mar 9, 2019
Messages
23
Reaction score
3
Country
United States
Hi,
I used this camera for 2+ years, and just now see that once disconnected it's died right away so current video file is not completed, file got corrupted and can not be played. There is no prompt <do you want to continue record..>, just black screen right away.

I think this is bad for whole idea for dash camera, no any video available once something happened with power, like when it's disconnected during the accident. I htink shold be internal battery or Cap inside ? anybody can share their expertise how I can replace it ? The unit has single screw on the top, but probably it's still somehow else conencted. + I would like to make sure that I can find right part .
Thanks All .
Best !!
all cder.jpg
 
open it up and have a look at the size of the battery, possibly has some numbers printed on it, a suitable replacement battery will cost a few dollars from somewhere like Aliexpress
 
A case of this shape is disassembled approximately the same for all similar dashcams. It is necessary to unscrew the screw (s) and disconnect the two halves that are on the latches.
How to do this, you can watch the video here on the example of another dashcam: How To Replace Car Dashcam Internal Rechargeable Battery
 
What he say in the video ( not many sell these ) i dont get, maybe his search parameters, i would search for 1 cell lipo battery + 400 mah
 
Thanks all for info, tried to check with Cobra for battery type, but looks like they outsource dash cam support to some other company, so not avail.
I will try to break case and locate the battery.
Best to all <@>><
 
Last edited:
opened it up: PT 462430 3.7V (for Cobra CDR 835). Battery has some brains with 3 connectors .
I probably can drop yellow and go with only 2 terminals (??) , it's probably some switch or overheat ? Could not see any similar on ebay by size.
I think I will wire AA underneath the unit, I have hidden behind mirror anyway.
 

Attachments

  • cobr2.jpg
    cobr2.jpg
    454.9 KB · Views: 15
Last edited:
The third wire will be to a charge controlling circuit. If you very carefully untape the old battery you'll find either a circuit board, heat sensor, or both which the third wire goes to. You absolutely need that left in place with the new battery added just as the old one was, then taped back the same way (preferably with 'kapton' tape). Lithium-based batteries can "vent with flames" if overheated like you've seen videos of hoverboards do, and that's not something you want happening in your face while driving :eek: Even if all you can source is a slightly smaller battery, it will probably do the job. Just be sure to rewire and replace exactly as it was before.

Phil
 
Thanks much Phil,
You can see insert on the bottom right of my pic with this piece of brain how it's connected. I probably can buy batt with 2 terminals and try to re solder that circuit.
I found some with 3 wires on Ali, not sure if they will work + need find color coding. In mine I think main are Red and Black. on the board they come together , yellow is bit aside.
This below even the same size, on my pic I measured width = 15mm but it's without those folding edges.

 
Freaky it have 3 wires, normally a 1 cell lipo you don't need a balance wire, but i assume it have to do with the charge circuitry in your camera.
All the battery cameras i have dived into have all been 2 wires.

The red & black wires are probably + and - and the yellow i a balance wire.

I am sure in your search for a battery you also found many more with just the 2 wires as that is enough as the balancing are done off the + terminal, so i am sure if you measure the voltage on red + black, it will probably be the same if you measure yellow + black.

If it have any charge at all, lipo batteries tend to die fast if they get below 2.8 - 3.0 volts. i have a cut off voltage of 3.2 on my lipo batteries for my RC cars.
 
Not long ago i had to swap battery in my mobius maxi as it had collapsed and swollen up.
658f213f0e22056a4808ffd280b000414b60cf53.jpg


Lucky as a geek with latent horder genes i have a few old batteries lying around, so just had to cut off the plug ( this camera have a plug for the battery ) and then solder the new battery to that.
 
Just want to check if this a G-Sensor close to lens opening ? Like on photo.
Tx
 

Attachments

  • 20200421_124004.jpg
    20200421_124004.jpg
    504.7 KB · Views: 9
Hi Leonauto and J,
Tx much, I thought it's too big for speaker :))
Anybody knows where is G-Sensore then ? I thought that Speaker is that tiny table at the bottom, just for beeping.
 
Last edited:
Tx Jokiin! * also second your P.S. mojo, I called it <to give people (dog) a bone so they can bite something>. Works really well in biz world too.
 
I got my batteries from Ali which I choose by size, and it's only 300mAH, anybody know if this is enough ? I could not read what is real capacity on the original, (see pic above). Original is about 6mm thick vs 4mm I got.
Cobra support not able to provide this information.

Tx
M
 
Last edited:
I got my batteries from Ali which I choose by size, and it's only 300mAH, anybody know if this is enough ? I could not read what is real capacity on the original, (see pic above).
Cobra support not able to provide this information.

Tx
M
300mAh will be fine
 
Installed new battery as careful as I could even splicing into existing wires without touching the board, and none is working, no beeps , no lcd. I changing the brand.
Tx all for help.
V)
 
Back
Top