Sometimes the manufacturers of various battery-operated products do not properly calibrate their low battery indicators. This results in the indicators "going off" long before the battery really needs to be replaced.
One good example: The GE Caller ID boxes. I personally had one blinking low battery for over six months before it actually started malfunctioning. The battery life before it started blinking was about a year.
Another good example is a digital wristwatch that is still going today, even though "LOW BATT" appeared on the display about seven years ago.
I wonder how many perfectly good batteries are wasted every year because of overzealous low battery indicators? I bet the equipment manufacterers are in cohorts with the battery makers. Conspiracy theories rule.