New PKCELL Batteries

Hi there. I'm a newbie here but I hope I can help with the cell database...
Recently I bought a protected PKCELL battery, individual packaging, well wrapped, protected. However, there wasn't any single data about it anywhere. This is the packaging:

[img=400x400]https://www.parts-express.com/Data/Default/Images/Catalog/Original/142-203_HR_0.jpg[/img]

All that was written is "high discharge performance". I couldn't resist, so I cut the wrapping open and found the marking "INR18650A260". It turned out it's actually a YikLik, 2600mAh, continuous discharge of 5A with 2.75V cutoff. Here are the detailed tech specs:
http://www.yiklik.com/upload/manual/INR18650A260.pdf

The battery is, however, decent and performs very well (for now). 2680mAh measured for one, 2644mAh for another, all on 3V cutoff!Both exceeding nominal capacity by far. If you drain them to 2.75V like proposed in the specs, I got about 80mAh more each.
I already have about 15 cycles with them in the Convoy C8+ flashlight. Here are some actual photos:

[img=600x450]https://preview.ibb.co/e0S21L/20181021-001725.jpg[/img]

[img=600x450]https://preview.ibb.co/fu55ML/20181021-001735.jpg[/img]

Cheers!

-Lu+ said:

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Recently I bought a protected PKCELL battery, individual packaging, well wrapped, protected.

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Click to expand...

From the photos that cell does not appear to be protected. Protected cells have a BMS PCB attached (typically to the top), and a wire running down to the -ve end

-Lu+ said:

Geek said:

-Lu+ said:

..

Recently I bought a protected PKCELL battery, individual packaging, well wrapped, protected.

..

Click to expand...

From the photos that cell does not appear to be protected. Protected cells have a BMS PCB attached (typically to the top), and a wire running down to the -ve end

Click to expand...

I think the protection is integrated into the battery body. It cuts on 2.60v perfectly.

Click to expand...

18650 Li-Ion batteriesdo not have protection circuits inside of them. (I don't think any battery of any chemistry has protection inside the cell itself)I would say most likely the torch stops working at 2.6v.

2.6v is too low for Li-Ion. 2.8-3v is as low as I go. To prolong battery life I typically don't go below about 3.3v.

Agree... does not look like the cell itself has any protection circuit.

The flashlight you are using does advertise itself to have a low voltage disconnect, that is most likely what you are experiencing here.

I am also unaware of any cell with an internal protection PCB... my experience has shown its always been an external add-on item to a bare cell.

Geek said:

From the photos that cell does not appear to be protected. Protected cells have a BMS PCB attached (typically to the top), and a wire running down to the -ve end

Click to expand...

BMS is typically located on the bottom (negative)

-Lu+, The batteries on the photos have no protection. If you bought on Aliexpress you can get some refund.