I fully agree with all of that, [MENTION=131376]PaulRivers[/MENTION]. I put a Sanyo under-BB dynamo on my wife's bike in the country because I didn't want to spend too much, and she may never need it. I want it to be there if she ever needs it. I put a bottle dynamo on her city bike for the same reason. She can't remember to keep things charged. Even though she uses her phone every day, it discharges unexpectedly often. She never proactively charges her stuff.