Heres the Ultratac K18… I think you have to take the head off and replace it with the charging cap.
I’m not sure how good its charger is.
Its not going to do 370L OTF from a NiMH or alkaleak…. ~150 OTF tops.
https://www.amazon.com/UltraTac-Powerful-Flashlight-Waterproof-Rechargeable/dp/B06XYYYL9Y