DC consumption translation to AC consumption
You'll take a little bit more than 22.5 watts from the AC outlet because a battery charger (a power supply) is a converter that is never 100% efficient. Typically modern converters are good for 85% efficiency so you'll take more like 27 watts from the AC and this is what you'll be billed for by the utility.

Regards what is written on the device, this is unrelated to actual power consumption.