This is something I always wondered about: when I leave my charger plugged on the wall socket but not charging anything, is it still consuming energy?
Some notebook chargers have a led that is always on, so I guess it's consuming at least a bit. But what about Apple chargers? I want to leave my iPhone and iPad chargers always plugged under my desk (so I can just connect my device when I want to charge) but I'm worried they shouldn't be plugged all the time due to safety risks or phantom power consumption.
Is there any way to measure this to be sure?
Best Answer
I measured my MacBook Pro’s charger, and the iPhone/iPad chargers, with a Kill-a-Watt-like device, and it didn’t seem to use any significant power when plugged into the wall on its own (e.g. it was less than 1 watt).
BUT:
I’m not sure if my device is sensitive enough to measure very small amounts of power though.
your mileage may vary. If you’re interested in this sort of thing, I’d get a little dongle of your own and do some measuring. Mine cost about £5.