Super cheap EAIEP 18650 batteries from AliExpress

Barkuti · 2018-10-10T06:05:43.000Z

Example: https://www.aliexpress.com/item/40pcs-lot-Original-18650-3-7V-2600mAh-For-batteries-rechargeable-Battery-ICR18650-26F-safe-batteries-Industrial/32795814865.html

€61.20 for 40 pieces to my country, even lower quote if you live in France and maybe other ground accessible countries. This must be because they use railway ground shipping.

I post this namely because those cells look like a 4-pack of fake green 25Rs I received some time ago, their capacities ranged from a bit above 2700mAh to close to 2800mAh, just 0K consistency and ≈35.4mΩ average DC internal resistance. This matches the capacity reports of the above sale, albeit you can also see other reports with capacities all :???: over the place.

I really wonder what kind of consistency and quality control is to be expected from such shipments. Buying additional spare pieces is probably advisable if aiming to build some pack with these cells.

As you can see, cells feature a 3 wide leg top (Samsung uses 3x thin legged tops). Can someone identify the OEM making them?

Cheers ^:)

BlueSwordM · 2018-10-10T17:04:28.000Z

From what I’ve seen on DIYPowerwalls, these are BAK cells, a trusted Chinese manufacturer.

1,62$USD/cell seems legit without paying shipping if you buy 40pcs.

Barkuti · 2018-10-10T19:06:46.000Z

Thanks for the point out BlueSwordM. I'm not really sure, didn't see any 3x wide leg top cells here. In the cell PDF document found in that page I see a cell model which sort of matches mine: number 10 in the list, model N18650CK, 2900mAh nominal capacity from 4.2V down to 2.5V, maximum weight 47g and internal resistance ≤ 35mΩ. My cells averaged 35.4mΩ DC internal resistance, determined it with a clock, precision power supply, multimeter, a few neodymium magnets and copper sheet and a friend's helping hand. My kitchen's scale measures their fake wrapped weight at 47.4g and 47.2g with a more regular wrap. Discharge test picture:

Cheers :-)