[roytam87]

AA or AAA batteries will leak.

[devilbunny]

If you have enough case space, that's not really a big issue. I work in a surgery suite; we have single-use (for sterility) items that use 8 AA's that will be discarded after five minutes' use. I effectively have all the free AA batteries I could ever use. Seriously, I could get easily get 40-50 a week if I needed them.

[johnklos]

Lithium AA or AAA batteries won't, nor will good rechargeable.

I just took some lithium AA batteries out of a system that were 25 years old. Not even a hint of leaking.