If we're talking about a commuter bike, a dedicated workhorse bike that you're going to ride every day, irrespective of weather, daylight, etc, I don't see how you can get by without dynamo lights. Mine have been in place since I put this bike together about three years ago, and in that time they have not required any attention from me. If the wheels are turning, the lights are on. I've had flat tires, replaced the chain, changed the crank, lots of minor repairs. But the dynamo lights are just there.
I'm all for redundancy, blinkies, rechargeables, whatever. And I'm all for commuting on a different bike every now and then, maybe even a bike without a dynamo light; that's what I have the blinkies and the rechargeables for. But if you're serious about commuting by bike, I just don't see how you can get by without dynamo lights.
I imagine some folks might not have a dedicated commuter workhorse. Might be commuting on a bike that is also tasked with some other job.
My question (just a curiosity); is are there in-line batteries for dynamo lights? Where I'm at, rural, lots of inattentive drivers as night who aren't necessarily distracted but seriously caught up in 'highway hypnosis'. They are used to being alone on the road. I'd be concerned about sitting at stop signs without any light. But such a setup would be cool if it still had a rechargeable battery. I understand Dynamo's probably couldn't charge that battery, but it could be recharged at home and used in such a way to just 'augment' the lights; keeping them consistently bright and working when stopped. Then when rolling, the Dynamo takes over, etc. Does such a setup exist?
More curiosity than anything. Even in that situation, if the battery failed; you'd still have lights as long as you were moving.