I have a Minitor 2, Minitor 3, Minitor 4, and a Minitor 6, by far the Minitor 6 has the best battery life, I get a moderate amount of calls, I have a few extra batteries for the Minitor 6 in my POV, To answer your question, you CAN change the battery when ever you feel its needed, I get around 2 days on my Minitor 6 on selective call without having to charge it, when the battery chirp goes off you should try to change the battery within the hour, if you are on call 24/7, like me, if you get a call for a Echo Level Cardiac Arrest, or a Delta level MVA rollover with PI, lives are at risk if that page does not go through, especially if your in a Vol. Deptartment where there is only a few that respond, this could lead to a fatal mistake, I know somebody is going to say "NoT EvErYWheRe Is LikE ThAT!", I have no clue where you live, or what type of Dept. it is, try to keep it charged up as best you can, change the battery when needed as well.
(This message was not meant to sound rude either)
I have a minitor 6. Love the pager alot. On selective call, how long will my battery last? Also should i always let it chirp low battery before charging it or can i charge it anytime? I dont wanna mess up the battery is all.