Hello fixit101 and welcome at CPF
This is the wrong forum, but pehaps a Mod. can move it
.
The bulb from the 3C needs max.4,5V since the original bulb in the stealthlite gets 6V max from 4xAA cells.
The nimh's you have used has less internal resistance against to alkys so I think it was too much for the 3C bulb.
Try to get the original bulb-reflector segment or perhaps a led-reflector dropin for 6V, which fits.
Best regards
____
Tom