from my experience with e-bikes:
To keep weight to a minimum, damn the cost: LiPo
Fairly light weight and low lifetime cost: LiFePO4
Most tolerant of abuse and of not terrible weight: NiMH
Decent abuse tolerance and lowest lifetime cost: NiCd
Lowest upfront cost but shitty in every other respect: PbH2SO4
My longest-ranged e-bike ran a 100-pound bank of lead-acid batteries, while my most fun e-bike had a NiMH trunk back. for lights sans traction needs, I'd go with NiMH or NiCd. (edited)