Thanks Bikescooby. Have had a look at the web page, they look really good and the usage time seems fine for what I need them for. My winter commute won't be more than 2 hours.
No phone works for me. I wear a RoadID tag in case I have a fall and somebody finds me or I ride with friends who have one. I suppose its one of those things, if you have never had one you don't miss it.