I've found the 3R I found that the battery last quite awhile while monitoring...it's the transmit that kills it. Kind of a moot point though, because the batteries (NP-60) are so cheap that it's easy to have a bunch for backup.
Does the 3+ use the same battery? I'm not sure how battery life compares to the small Yaesu, etc models.
84 FJ60 The TuRDle
& '89 Pickup Ext Cab DLX 22RE/5spd