I've never had a tire pick up a nail in in 30 years of riding on a large variety of motorcycles. Since I've owned my 2008 C14 I've picked up two nails in the rear. The TPS told me both times while there was still plenty of safety margin. I'm kind of wondering if there is a powerful magnet in that sender device that attracts nails/screws?
Anyway, I still have the original senders and batteries in my tires. Since I ride here in MN from March through mid-November I have to see the low battery warning plenty of times until the tires warm up. I can always tell when it's lower than 50 F outside! One of these tire changes I'll probably do the battery swap but thus far it seems I'm always in too much of a hurry to monkey around with it and I obviously don't mind the warning that much. It goes away in a couple of miles.