I wanted to get a portable analyzing charger and it seems that the smallest full-featured one would be the Opus BT-C100 charger. It has almost all the functions of a bigger analyzing charger (which I already own a few), although with only 1 slot - it is designed for portability.
I purchased a unit from Banggood, but when I tried to charge an 18650, it DOES NOT seem to charge them. It will seem to "charge" but then shows "FULL" immediately (tested when the battery voltage was only around 3.9v), after inserting a few seconds, it shows FULL, and testing the battery voltage shows it's still at around 3.9v. I also tested with an 18350 and it's the same behavior. Tested other 18650s at different voltages, and they appear to charge but then displays "FULL" very quickly.
I did a video to demo the problem to Banggood:
testing the Opus BT-C100 with an 18650:
Banggood replied back and told me to test other battery types. I don't have a LiFePO4 battery, but I have NiMh, and it appears to charge NiMh properly:
Now after showing both videos, BG replied back and pointed me to their product page description:
The product description indicates it charges: LiFePO4, NiMh, NiCD
There is NO indication that it can charge Li-Ion.
BG's response: I am using a battery type that is not supported by the Opus BT-C100 charger.
That seems to be an unreasonable response. What do you think can I do?