Is it true that you use a lot of electricity by leaving your phone charged plugged in after it is charged?

It is not true. Cell phone chargers use feedback circuitry to determine when the phone battery is properly charged and then basically shut off. Actually, they don't shut off entirely as they are still powering the phone (if the phone is on), but the amount of electricity used is extremely minimal. Maybe a watt or two.

There are 8,760 hours in a year. Let's say you still use a full 2 watts of electricity when the phone is fully charged but still plugged in. My electric bill costs me about 13¢ per kilowatt-hour. So, in an entire year, you'd use up $2.28 of electricity by leaving your phone plugged in 24/7. Not a "lot" by any definition.

The average charger or power supply transformer uses about 15 to 20 watts of power when it's plugged in but not being used. Same with electronic equipment, like a cable box or TV set, that's plugged in but not powered on.

definite it does. in case you have a charger that has a splash mild on it that facilitates you to be responsive to that is plugged in it is likewise possible to make certain it. That little mild does no longer be on if there wasn't electrical energy working thorough it. something plugged in attracts electrical energy.

No, but you will still be using some.