I am not able to charge with much more than 1.5A before charger goes into CV.
What are your max charging current in CC mode and what kind of holder/connection are you using? I think it should be higher that what I am getting, I suspect protective circuit or battery holder might be the bottleneck.
It’s way less that I can push in with my RC lipos.
Empty was the battery. Any one of mine: trustfire, Sanyo, Panasonic.
How are you connecting to the battery? What holder? Magnets?
edit: trustfire 2400mAh, sanyo 2600mAh, Panasonic 3400mAh, all protected.
holder is the crappy thin wire 4x holder from dx, charging only one battery at a time, using SkyRc Imax B8+ charger.
I will try perhaps to remove protection from one of the batteries to see if it is introducing the voltage drop.
I use cheap holders too, but soldered the end of the spring directly to the wires (so current bypass the spring).
I also rigged another line out of of my Imax B6, this is directly soldered onto the mainboard. I use 2.5mm^2 wires (AWG14/16? Not sure the conversion).
Basically I have fully soldered connection end to end. Helps in testing/fully charging batteries without voltage drop on connections.