I just purchased an HRM-Run and am trying to find out if there's something I need to do in order to 'turn it off'. With prior heart rate monitors, it seems like un-snapping the metal buttons would disconnect the battery and keep from running down the batteries. The HRM-Run doesn't have any metal snaps. So how does it turn off and stop consuming power?
The HRM4-Run ceases transmitting when the device's internal ‘smarts’ decide to do so, and it isn't up to you to exert control over precisely when it should stop doing anything that consumes battery. What you can do (and all you can do) is to take it off your chest and hang it up – short of removing the red cap on the HRM module and removing the battery.
Let's say you have to replace the CR2032 once every six months instead of twelve, because of the lack of diligent and precise control over when the device is off. That's only a few dollars and a few minutes more you have to spend in a year; does it really matter?
FYI it turns itself off if you stop moving for a few minutes. You’ll notice this if you take an extended break in a long run, for example. (You might see the “external hr connected” notification when you start moving again.)
