Non-rechargeable lithium batteries are generally good for one thing: 10-year shelf life (at the store, or in your emergency flash light).

For frequent use, *rechargeable* NiMH batteries are a much better solution, both for you and for this planet.

I do use alkaline AA's in my own LED headlamps, though, as they have a longer "shelf life" than charged NiMH batteries.

Cheers