This is the 2nd gen PS3 remote right? (The one that has IR for other devices too?)
As I understand it, this remote doesn't remember pairing when the batteries are removed or go dead.
I was trying to use one, and I'd be tickled to get more than 2 days out of a set of batteries. What the stand by function you're referring to? I have kodi doing an 'idle shutdown' after an hour if inactivity, but it don't seem to affect the battery life in the remote.