i find that multi-celled lights aren't as reliable as single cell because they have more contacts to corrode, and if one cell fails, there other(s) can't do the job.

thus, when i can, i prefer single-cell models with extra batteries carried separately.

also, i don't leave alkalines in any flashlight. instead i store them with lithiums or NiMH rechargeables.

and if you've been buying multi-celled lights because they're brighter, maybe a brighter higher-end single-cell is your answer.

ie: a carefully chosen 1xAA light can pump out much more light than most versions offered in hardware or sporting-goods stores.