Hi, yes indeed it could be recycled parts, or maybe quality failed parts, but could also be fully new parts .. We are not actually don't know about this, we did just resell it, sorry we didn't specify this enough.

This kind of battery better use a special cc/cv charger and stop charge at 3.6~3.7V.

I also just contact the supplier of this, he said 8C can work, maybe we will test to improve this later.

Thanks!

I have mixed feelings with respect to these batteries.
- I am not sure they are new. Theirs legs seems to have been cut.
- Their discharge capacity is not at all what is announced. It is announced that charge and discharge current is at least 8C with a nominal 220 mAh. This is certainly not true, as the discharge current cannot go much beyond 0.2A (I.e. 1C) about the same for charging current ( maybe 2C). Is this because they are used ?

I have made many tests for measuring the capacity (3.6 V to 2.5 V) on 3 different batteries.
- At 0.4 A CC discharge, the capacity is just 170 mAh
- At 0.2 A CC discharge, the capacity is about 500 mAh

Good product that comes into pre-cut board (especially if you order more than 1x 5), has to be separate by hand, but it is not a problem. Tiny board that fit perfectly my project. Very simple, Tx in ;Rx in ; Tx out ; Rx out ; - (GND) and + (3.3V or 5V). Tested and works good.
Well packed - Box & bubble bag. Quick delivery in the actual international Covid context, within 15 day by DHL 6-10 days.