I'm useing it for 12 years!!! on bike, runing, climbing and trekking.
One bar geave me the power to go on for 2-4 hours (on the bike and running 2h-and on trekking for 4h)
And it can be in the bag for 4 days on temp of 42C!...it freeze in -4C (+32F?) and you can only lick it!