In need of a new battery

My cyclometer stopped working today. It had been rather erratic these past two weeks. Replaced the battery and it's now working fine.  The battery is the one I used in my rear lights for two years until last year when I replaced it because I thought the battery had gone flat when it hadn't.  I don't expect this battery to last.  Both my cyclometer and my rear lights use the same CR2032 battery.