70mai Dash Cam Battery Pack

[Panzer Platform]

It’s like an engine only firing on three cylinders instead of on all four.
It drives but we shouldn't drive like that to prevent complete engine damage.

Connecting cells first in series then in parallel or vice versa, react differently on damaged cell, depending on how the cell fails (short or open or somewhere in between), neither way is fully safe.
If you connect cells in series group first, then in case of the short for one of the cell in group, the remaining cells in group would be at lower combined voltage relative to other groups in parallel, which is really not good because higher voltage group at 4 x 3.6 =14.4V will charge damaged group which is limited to 3 x 3.6 =10.8V to equalize the voltage, this will over-voltage remaining cells and this is not safe with potential fire hazard.
Nevertheless, the BMS should detect the failed cell and provide warning and stop some operations like charging or better shut the battery down completely.

So to confirm my original statement;
“If any one cell fails, the entire pack will be inoperable because the BMS will detect the malfunction, and prevent charging”
It is NOT an issue of loosing capacity.
It’s all, or nothing.
Is this correct?

 

[kamkar]

woke up to a TXT from my dashcam today, the battery was low and it had shut down.
Mind you the 4G was still on, and i could also " call in " wake up the camera and get a live view.
So i spent a little money on the interweb, and a good hour later i got a MSG saying my stuff was ready for pickup, so i took a lengthy drive to recharge the battery, mind you the drive to the pickup point was just 50 minutes or so MAX, but upon arriving there i had a full line of LEDs on the power bank indicating a full charge.

Tomorrow i am once again going to the range to hone my accuracy with the rifle, and of course also do a little building on the new shed CUZ it aint fully winter ready yet.
Anyways once parked there i recon it will be upwards of 30 hours before my car will drive again, so i am going to see what this battery can do uninterrupted service.

 

[GPak]

So to confirm my original statement;
“If any one cell fails, the entire pack will be inoperable because the BMS will detect the malfunction, and prevent charging”
It is NOT an issue of loosing capacity.
It’s all, or nothing.
Is this correct?

Correct, for a fully or near fully faild cell.
Any 'selfrespecting' BMS has a max allowed imballance setting between cells (any two cells), once that imbalance is reached 'selfrespecting' BMS should shut the battery dow.

It is an issue of losing capacity, only within that imbalance threshold when the cell slowly degrade, and it is not practically different for 4, 8 or 20 cells.

 

[Panzer Platform]

woke up to a TXT from my dashcam today, the battery was low and it had shut down.

Would you be so kind to see if the battery pack can be charged by connecting a standard Type-C cable, and power brick?
Or better yet a Type-C Laptop Charger?

 

[kamkar]

Dont really have any powerful chargers here, CUZ not fan of fast charge. but yeah i do have a wall wart that can charge my phone and action camera.
I will see if i can remember this when i get back home

Dunno why you would do that though, i could not be bothered with taking the power pack in and out of the car.