Last evening, I was using a pair of pocket wizards to trigger a D800. I had an SU800 on top of the camera to trigger some remote strobes. On quite a few occasions, the SU800 went to sleep before I was able to trigger it. I had replaced the battery recently. I replaced that SU800 with another one, and it seemed to work okay.
Is there a setting in the SU800 I don't know about that controls how quickly it might go to sleep? The Pocket Wizard is connected to the camera with the special cable designed to keep communication open.