[Android Central Question]

S10+ rated for 12Watts wireless charging. Can you use an 18Watt wireless charger without damaging the phone?

[Hermes Hidayat]

S10+ rated for 12Watts wireless charging. Can you use an 18Watt wireless charger without damaging the phone?

You can. The device will only draw the amount it needs. For me as an example, i use Spigen F306W wireless charger. It's rated 15W or lets say UP TO 15W. so its safe.

[dbollman423]

I believe so. QC 3.0 & QC 2.0 are supposed to be backward and forward compatible.

[Rukbat]

A device (anything, a phone, a light bulb) will draw only what it's designed to draw. Your house is a source of, probably, 22,000 Watts, but when you turn on a 100 Watt light bulb, it draws only 100 Watts.

The phone and the charger "negotiate" over the data lines (USB consists of power wires, data wires and a few others) to determine the maximum voltage the phone can accept, and the charger sends the phone current at (or below) that voltage. (Except in an old "non-fast-charger" - then the voltage is 5 Volts, it can't change.) An 18 Watt charger can supply 9 Volts at 2 Amps, but it can also supply 12 Volts (probably at 3 Amps - which is 15 Watts, and probably what your phone wants), and that's what will happen.