Originally Posted by
Braindrain
Bad for charger but they're pretty sturdy. I plug mine in in-seat power all the time and it's still going strong.
I killed a Lenovo X61s extended battery plugged in to in-seat power on a Delta flight from LYS to JFK. I noticed that the power kept flicking on and off (so that laptop kept switching between external power and the battery). Back in the office, the battery no longer held a charge. And some of the ports (powered USB, external monitor) no longer worked. Not sure if that's related, but it would be an awful big coincidence.