A sign that the battery is going is when it fails to read on cold mornings. Last year, when riding to work in winter my speedo would take 30mins before it would give any speed readings, although the elapsed time and clock were still working, once the weather warmed up the speedo would start to work. I eventually bought a volt meter for $5 from a car shop, this way I get the most out of those expensive batteries.

The volt meter also makes it easy to work out which battery needs changing, the top or the bottom one. With three bikes and three speedo's it gets used quite a bit.

CHEERS

Mark