Stalling 2003 Nissan Maxima

Car stalls every so often, but not always, at stop or coasting to stop. Loss of power steering, brakes. Check engine oil and battery lights come on. Car restarted after a few cranks. Took it to mechanic - no codes came up, alternator seems ok, ran fine for the week they had it. Suggestions?

Try cleaning the battery ground connections, both ends.