Charging Devices in Flight without the use of Batteries

[747sp]

Batteries on a plane.

Just a question for the experts. With the new rules of not being able to use your battery on the plane i was wondering is it faster to charge my phone/ipad , using the USB port or is it better to bring a charger and use the power point provided?
Also would you use one of the higher capacity cables or it not relevant.

I tend to use flightradar 24 too much when flying and have an old phone

 

[jb747]

Wouldn't the charger convert it to 5 volt as it does with 240v and 110v?
What voltage are you referring to?

400 volts. Convert that.....

If a seat charger trips, it will most likely trip power for the entire seating row, not just that seat.