1998 buick park avenue ultra.... stalls

ok ...car runs good but in the last few days the car will stall for no good reason.3x .it would always start right back up...yesterday the car stalled and everthing went dead..no power what so-ever..after about 10mins the car started ..had to re-set the clock and everything..it was like the battery was taken out ..tested the battery and its ok full charge...at first I was thinking it was the crank position sensor that was making it die...that was untill everything went dead...Im kind of lost here...please any good ideas befor I take it to a shop...Oh and I did a OBD2 test and no codes..thanks

Welcome to AF, check the ground and positive connections leading to and from the battery, loose or corroded.