Is Qi / wireless charging safe? Heightened temperature not an issue? (Nexus 7) A friend of mine told me, like it was a fact, that qi (wireless) charging is not safe and it damages battery because it heats it. I just bought one charger, but would like to avoid damaging my Nexus. Could not find out any information about it on the internet though, which makes me even more sceptical, that it just might be a rumour of some kind. 

I am currently charging right now and it is getting kind of warm. The temperature according to a system monitor is just 32 degree Celsius. Seems normal to me.
I am charging the device regularly and checked with a system monitoring app the temperatures, that I reached. It was never more than 33 degree Celsius, while charging or after charging, still laying on the charger. 

This is to be considered a completely normal temperature. Just today I was out with the tablet  on the sun and I reached more than 40 degree Celsius, just because of the sun, so I wouldn't really consider charging with Qi an issue.