Why won't my PS3 Sixaxis controllers connect?

I can play for about a half an hour sometimes and then the controllers will shut down on me. The controllers are charged and they won't work even if i plug them into the usb. Resetting them does not work either. The Sony BD Remote does not work either. It happens when I am playing a game and when I play movies. I've also tried moving it away from my router and there are no other bluetooth devices in the house to interfere with it. I have tried everything I can think of or have read besides paying the $150 to send it. Any ideas?