Originally Posted by
Craig6z
While I see this solves the potential malware problem, AFAIK the USB ports on planes are 0.5 amps. At that low current flow, very few devices other than a smartphone will benefit from the miniscule 5 watt output. Even a smartphone (in airplane mode) may draw more current than being replaced, depending on what you are doing with it
This. I carry an inline meter to see how many amps I'm pulling (they're like $7 on Amazon). I did check a DL plane once and it was 500mA (0.5A) which takes forever to charge most devices. iPhone for example pulls about 1.5A at peak then drops down to about 1.1 and then lower as it reaches 100%. iPad ~2.3A peak. IIRC, an iPad will not even charge off of 500mA.
500mA was the original spec for USB power Eons ago, but there are still many devices out there that only support 500mA. My power bank provides 4A, so that's plenty to charge either an iPad or iPhone. My laptop usually lasts 6-8hr so I just charge it prior to flight.