The parent's point is that the circumstances would dictate how quickly the battery drains, so it wouldn't always last a year on full charge. (And therefore not

The parent's point is that the circumstances would dictate how quickly the battery drains, so it wouldn't always last a year on full charge. (And therefore not always a week with > 2% charge.) That said, it's not trying to keep it chilly, just not deathly hot, so I expect it would still be fine.