kanton
(kanton)
11
I checked the Seeker 2 Pro - the proprietary battery there goes into the flashlight the other way round than in the M2R Pro.
Seeker2: Regular Minus towards the head, Plus and “artificial” Minus towards tail.
M2R Pro: Regular Plus and added Minus to head, regular Plus towards tail.
So from this setup it makes sense that the Seeker2 Pro can’t charge regular 21700s but but can run with them, as the additional Minus at the tail apparenly is only used for charging.
On the M2R Pro they apparently opted for using the Plus and “artificial” Minus in the front to drive the light. That would explain why it works without the tailcap installed just using the side switch. This also means it can never run with a regular battery. If my guess is right it might charge regular 21700 battery though (which would be interesting but utterly useless).