The Terralux drop-in (really a "screw-in") is great, but he said he needs one without
threads, so the Terralux is out.
I was running a 5D with a 4-cell Mag module for a while and it didn't fry.
I didn't use it a lot, so I cannot vouch for a long lifetime run out-of-spec like that.
I was using NiMH, NOT fresh off the charger. I switched to the Terralux screw-in
(since mine is a real Mag) and will probably be selling off my old MagLED
modules soon.