I'm not a fan of NIMH chemistry. The self discharge is very bad and it also seems to be fairly short lived. The batteries seem to start going to hell almost immediately on capacity and just don't stand up to a lot of real world use. Basically they go to hell after a couple, sometimes three years, meanwhile I have a couple of Nicads in my electric shaver from 1999 that are still going strong. If you're willing to put up with a battery that might go to crap in three years time, lithium ion is a much better choice for energy capacity, and the lithium ion cells nowadays are lasting a lot longer, like 5 years or more.
You might be better off to do like I do and keep a spare flashlight and lot of extra lithium batteries and bulbs in the glove compartment. You won't run out of flashlight before daylight.
