I think my iPod touches never lasted more than 3 or 4 hours on a charge. Apple never got them to do better. My iPad 3 would go a whole day, but I never actually timed it to see how many hours. My Mini hasn't been mine long enough to test yet! BTW, airports in the USA seem to have charging stations scattered about.

I got the iPad Mini 2 WiFi version because my T-Mobile iPhone 5 can be used as a WiFi hot spot.