Dead car; not Aux Battery

My 2001 Prius has been running perfectly until 2 days ago. After parking it and shutting it down overnight, it would not start. In fact, nothing electrical works at all... doors, dashboard, lights, etc. I suspected the AUX battery and took it to our Toyota dealer. They test it and said, "The battery is perfectly fine. It has full cranking power." So, now what? I know the fuse at the AUX battery is fine. I'm going to check the fuses in the engine compartment. What else can I check?? I'm also going to try to jump start it (per the manual).

 

I think I solved this... After the dealer charged and tested the AUX battery, I got the car running again. And I noticed the 2 map lights were ON. I asked the person in our family who used the car last if they had turned those lights ON. The answer was YES... (they obviously forgot to turn the lights OFF before shutting the car OFF). So, I drove the car for an hour to charge the main battery and I think all is well now.