i went through 4 or 5 of them, in less that a year, and have stopped carrying them together with my keys as in 2 instances i suspect the keys did the damage. two other times it just did not display anything.
the one that i have now i have not taken out of the original packaging and sits on my computer desk, lasted a bout a year now . i just have to make sure i don't forget to bring it when i travel. if i need to do some stuff online during the day, i just try not to forget it and do it i night. sometimes a PITA!