Without any protection diode, you run the risk of shorting out the batteries if something comes in contact with the charging rings, correct? Do you place tape over the rings when transporting / using the light?
(I temporaraily modded my MC with 3x18650 cells powering a WA1331 lamp. I was comtemplating modding the charge craddle for Li-Ion use, but have decided not to for now. Plenty of other projects going on, and I kind of like having a stock MC around as a point of reference)