Originally Posted by slojko
I picked up a wireless charger the other day and when I used it I noticed my phone was pretty hot after. Hotter than normal USB charging. I went to read the manual that came with it and it said the maximum input voltage was 5v and I was using a wall USB outlet that outputs 1000mA which is about 9v , I know that's bad but would have damaged my phone at all or only my wireless charger??
A wireless Qi charger will be warmer overall than corded charging, it's nothing to worry about (try playing a graphically intense game for an hour on the Nexus 5, that's heat).
When the charger says it will take 5V input, that is how much it will draw. For example, if an adapter outputs 12V, that's how much it can provide, NOT how much it is forcing in to a device. So the Qi charger is drawing 5V out of the 9V your USB wall charger can provide. The other 4V aren't utilized.
Same concept for example on a desktop computer. If you have a 1000W power supply and your computer is in sleep mode, you power supply is not shoving 1000W forcefully through the computer. So your computer is using like 100W and the remaining is available when needed but not active.
Don't worry, you're all good.