From AMSAT News -
AO-92 has been experiencing low battery voltage during many night time passes over the last several weeks.
While the satellite is in eclipse voltage has been dropping low enough (3.6v IIRC) to cause an automatic shift to safe mode. It emerges from eclipse toward the end of night passes over North America and the transponder will then switch on, usually with a minute or two remaining in the pass. As we move to winter in the northern hemisphere, the end of the eclipse should shift over the pole and to the beginning of the descending part of the orbit, and this issue should change for at least the northern hemisphere ops.
[ANS thanks Andrew Glasbrenner, KO4MA, AMSAT VP Operations, and Nate White, N5LEX, for the above information]