only ever use the proper army issue ones. (not cheap)
I tend to have a few in my backpack at all times, they last well beyond the expiry date, many varieties for short / long burn duration.
i've found them valuable tools indeed stuck up a mountain in sub zero temperatures in a 4 man gondola after dark to signal & stop my mate going insane!
8 hr burn standard would be fine, but expensive| to do.
simpler just to use some led fairy lights & block off the ones you don't want!
No, i'm not back.