I'm a new 580P user. Used it for the first time this morning on my trainer. I'm impressed by the workmanship of the material and the flexibility of the software. I have an "old" Polar wearlink+ strap for which I ordered a garmin Premium Heart Rate Monitor transmitter from ebay, so will soon be tracking pulse. I'm also trying to choose between the garmin gsc 10 and bontrager interchange combo sensor for use on bike #2.
Anyway, my question is about runtime with gps off. In early March I will be doing an extended trainer ride to raise money for my church and I'm hoping the device won't die on my.