Do chargers use power when they're not charging?

Question

1) If I connect my mobile charger to a wall socket and it is switched on, but I don't connect my mobile to the charger, does the charger still use electricity?

2) If I connect an extension box to a wall socket and connect my mobile charger to my extension box, but again I don't connect my mobile to the charger, does the charger still use electricity?

I want to make sure my electricity bill is not going up.

This is a good question for 2015, because almost all chargers are now switch mode, and run very cool on no load. The duplicate question is 5 years old, when they were often still warm transformers. — tomnexus, Feb 05 '15 at 17:18

score 5 · Answer 1 · answered Feb 05 '15 at 12:32

If you don't connect a charger to the device it's meant to charge, there will be very little electricity flowing through the charger. (There will be a little bit leaking through, but it's usually not significant.)

As a rule of thumb, if your charger doesn't feel warm, it's probably not using enough current to affect your power bill.

score 1 · Accepted Answer · answered Feb 05 '15 at 12:32

i need to make sure my electricity bill is not going up

Don't plug it in is the only answer. Even without a phone on charge, some power will be taken by the charger and you will be billed for it. It will only be pennies per week but if you want to avoid extra cost then don't do it.

A power cord extender will not affect the situation other than to slightly (pennies per ten years) increase your bill because of the small volt drop down the extension cable dissipating a the odd milli watt due to it passing current to the charger irrespective of whether the phone is plugged in or not.

Do chargers use power when they're not charging?

2 Answers2