I know a lot of folks have been helpful in posting their interpretation, opinions, and explainations as to why rechargeable batteries should not be used with the Mag LED lights and upgrade modules, but I thought I'd just pass something along that I noticed when going through some packages of Mag branded bulbs.

The entire warranty disclaimer that is on the Mag LED upgrade modules, including the part about the rechargeable batteries is the same text, verbatim, that Mag Instruments has used for many years on their Mag branded replacement bulbs (both the Krypton and Xenon bulbs.) As such, I don't know how much of it is actually applicable.

Personally, I've been using C sized NiMH batteries in a C sized body with a 3 cell LED ever since I bought it, though it's probably too early to tell if it has had any ill effects (seems to work quite well.) On the other hand, according to Streamlight, NiMH batteries should be used in the SL 4AA Propoly Lux either ...