5,2 volts to much for the raspberry pi?

Most devices that use a 5V power supply are rated for 5V +- 10% (4.5V to 5.5V) or 5V +- 5% (4.75V to 5.25V) and so you should not have any problems with it.

RasPi is designed for the USB power voltage range 4.75V to 5.25V, so a "5.2V" supply should be fine as long as it's not producing more than 5.25V.  Also, there will be a small voltage drop across the Micro USB cable and RasPi's polyfuse F3 (Model A/B) or F1 (Model B+), so it's nice to have a little more than 5.0V.  The actual drop depends on how much current RasPi is drawing as it performs different activities.

Here are some useful links:

RasPi Troubleshooting Wiki: Troubleshooting Power Problems

Peter Oakes' blog: Raspberry PI: USB power cables, crashing and other problems

Here is a link to adafruit.com hope it helps

LOL, I was just about to link my blog on that, Thanks John, gets the info to Bruce quicker.

To summarize, there is no need to use a 5.2V adapter, if you have a good 5V one already. If your having issues then look to your USB cable, there are so many crappy ones out there, also if you have multiple devices on the USB, use a powered hub instead. If you have a multimeter, try different cables and measure the volts across TP1 and TP2, pick the cable that gives you the best voltage (Highest Voltage reading)

This alone should fix any power related issues you have.

Oh, and a 5.25V adapter is running the chips right on the edge of their MAX ratings, this I do not recommend.

Regards

Peter

Oh, and looking at the adafruit link reminded me of another thing, D17  is a 5V zener, you run the risk of drawing even more power as you entering the breakdown area of the zener

John/Peter as you both say the .2 V is lively to be a benefit if anything. Just enough to allow for the volt drop getting in to the Pi. Also the PSUs tend  to sag a  fraction when underload unless they are quite good ones

Out of interest is this a B or B+. The B+ should really have a bit more latitude with the switching PSU on board.

Conversely with the lower current draw it will have less need for  the increased head room .

Also is his multimeter even that accurate ? 1 % will bring it to the edge of the range, It may be worth checking against some known good source or another meter just to make sure.

I have a B and a B+ as well as a good quality LAB PSU so I will test to find out

Stay tuned

Thanks for all answers guys! I Just bought the model B+ and it is my first one so I did not want to burn it or blow it up...

The B+ is much more efficient with the power supplies on board so you should be ok with the 5.0V adapter, remember that 5.25 is at the MAX Rating, not the recommended so if something causes it to increase its output like a short surge or something it can easily exceed this MAX rating