Q about C cell replacements for led

[Kilili]

I'm looking at a photo of an AElight LifeLight65, and it shows it can be powered by 3 C cells, or what looks like two long-length 3.3v batteries of the same diameter? Can anyone comment on what these are, and the belefits of such?

 

[gswitter]

They're rechargeable LiFePO (Lithium Iron Phosphate) cells - 3.2V nominal, 2800mAh.

Advantages over alkalines cells:

• they can maintain higher current draws
• they're rechargeable
• weight (maybe)
• they don't leak
• (I'm sure there's some other stuff I'm forgetting)

Why you would choose those particular LiFePOs over NiMH Cs? I don't know.