The one thing that keeps me from pulling the trigger on some bike computer is the lack of information about the odometer, the lifetime mileage on the bicycle. When you change the battery in your car, your electronic dash odometer doesn't go to zero. It would be stupid. When my Samsung Note 4 battery dies right in the middle of something, I remove and replace with my hot spare and it remembers right where it left off. I've been told not all bike computers are nonvolatile like this.
Which cycle computers are able to remember information when the battery is changed? Or better yet, is there someplace in the spec sheet or other way to find out if it has non-volatile memory without buying it?