PS-1 does not need a battery to run.
I removed most of them from mine, back when I messed with conventional. There is no sound when you change direction.
I did this with 5 or 6 locos (only way I could get my 2 GP38's to reliably sync-up when double-heading); they all work fine.
Eliminates the "dead battery chip death", too.
True of all PS-1's? Dunno.