At a recent class I ran my truck gun which is set up with only Troy Micro Battle Sights. It makes for a true truck gun that doesn't need any optics battery maintenance. I did this for a couple of reasons. The first is that in the past I've had optics go down on me in the most inopportune moments. I actually had an optic fail during a Larry Vickers class which you can imagine is not a good thing to have happen. Larry is hard on students that don't come prepared and the truth is that I really should have opened up the optics on my rifles and verified the date stamps on the batteries. Coincidentally, one of the things you can do for yourself is to take a fine tip Sharpie marker and write the month and year on the battery before inserting it into the optic. That way when you open it up there's no guessing how long that battery has been in service. Whether your optics are running or not is irrelevant, you really should be changing your batteries about every six months, but definitely no more than every 10 months. At this class I dedicated myself to run iron sights to be sure that I would not have the option to revert back to a red dot optic when things got tough. Not only did I do well, I did extremely well. None of the good guys down range were hit, and as far as we can tell every shot went through the bad guy. I wore a Bravo Concealment DOS in AIWB which takes some getting used to because the rifles bumps into it through the shirt. That's not a deal breaker it's just something to be aware of when doing this sort of thing.
Train and Carry with the Best Concealed Carry Holster.