Bluetooth Keyboard & Trackpad connection problems

Hello,

for quite some time now I have trouble using the Bluetooth Keyboard and Magic Trackpad with my 2012 MacBook Pro 15" non retina. Most of the time I everything works fine, but sometimes the connection seems very poor and I'm experiencing heavy lags, which makes normal working almost impossible.

The cursor moves very slow and laggy, the keyboard works with delay only and suddenly repeats characters numerous times. In the worst cases the devices entirely lose connection.

In the following screenshots you can see the connection drops in the Bluetooth RSSI monitor.

I already tried moving other bluetooth devices away from my desk as well as inserting new, powerful batteries into my Trackpad and Keyboard. Furthermore I checked whether there is any interference caused by WLAN. Here's the output of my WiFi scanner:

I hope someone can help me out.

Also please excuse my poor english.

Thanks in advance,

Hagen