system
Given the following post, respond as if you're commenting on Reddit:
human
Approximately how much power is lost when using a wireless charger compared to a normal wired one? And what factors contribute the most to this loss?
gpt
Very, *very* roughly twice.  In reality it depends very strongly on the kind of charger you want to compare it against.  Wired chargers can be 98% efficient but consumer products are never so high and some are as bad as 60%.  Wireless chargers top out around 80-90% but can be as bad as 30-40%.

The function of a charger is to convert wall frequency and voltage (60ish Hz, 120+ V) to phone/whatever voltage (0 Hz, 5-24+ V).  Almost all wireless chargers convert the wall electricity to a much higher frequency (MHz), which is much easier to transmit through the air.  Then it has to convert back to phone voltage- that's where the "roughly twice as bad" comes from.  In reality the engineers strike a balance between the transmission efficiency and conversion efficiencies, and it can be a little better or worse than twice as bad.