My Dell power adapter supports
up to 130W, i.e. 5W more than the
125W that British Airways claims to support. If I measure the power that my laptop causes the adapter to draw from a UK mains socket under normal usage, it is usually around 40W. Even if I'm charging the battery and doing using of power-hungry graphics, it doesn't draw much more than around 100W, which is still well short of 125W. But every time that I plug this adapter into a power socket on a BA 787, or any other BA aircraft, the power light on the socket immediately goes out, even before I connect my laptop to the power adapter. This suggests that BA's claim to support 125W is a lie. Or am I missing something?
It is probably the switch on surge current that is tripping the socket; this can be an issue with well designed piwer adapters with adequate input filtering.