LiMn or Li-ion?

I have not tested the BestInOne IMR cells.

The IMR I have tested can easily handle 5 to 6 ampere, I tested up to 20A.

All batteries does have sag, at higher currents IMR are some of the best, but 3.8 volt is to high.

They can hold 3.6 volt for a short time, see my battery test summary, 3.6 volt bar graph.