I’ve had Cateyes and still have one on one of my bikes. I did need to start it since it would go into “sleep” mode when not in use. Battery generally would last for years.

Bought a new bike last year at my LBS and had them add a Cateye. I had nothing but issues with it and the LBS wasn’t real helpful. I was instructed to change the battery, which they gladly sold me. Told me if that didn’t work to change the battery in the sensor. So, it didn’t work so I purchased another battery for the sensor. It would still show me going 62+ mph at times and trust me, I can’t ride that fast and wouldn’t want to. So, I don’t know if Cateye’s quality has diminished or if I had a bad one. I recently “donated” the unit back to the LBS where I purchased it and expressed my disappointment with their service. No wonder the LBS’s are disappearing since I can get that service from most companies online.

So much for my rant. I downloaded the Supercycle app on my Android phone and have been using that with no issues. You do need to start it when you begin, but it does auto-pause during a ride. Phone stays on the entire time, but it doesn’t seem to drain the battery too quickly. I’ll ride 1.5-2 hours and if I start with a full charge, it might be somewhere around 80-90% left when I’m done. You do need to end the ride to complete it. It keeps track of what I’m looking for and it was free, so there’s really no risk.

Hope this is helpful. My reason for the rant was that I’d be hesitant to use a Cateye again based on my recent experience.If money didn’t matter, I’d probably buy some Garmin unit since they tend to just work.