Good advice. I use the depleted but not drained batteries in my radio. I keep a rubber band around the fresh batteries to identify them.

Another piece of good advice is to run with two rear lights in case one fails, and you don't know about it.

What about halogens?

The ones I tried did not compare. Not even close. One was a Cygolite and one was a Planet Bike. Good run times, not enough light. I'm not sure what you would have to pay for a halogen that matched some of these P7's and the Fenix lights.

I Do ride with both front and tail light on in daytime, but not all of the time. My 3W LED front light (~200 Lumen) is not very noticeable in direct sunlight.

My bike is in these pictures, on the sidewalk with both lights on. The car on the road also has its lights on for comparison:
http://img12.imageshack.us/img12/576...ting017.th.jpg
http://img19.imageshack.us/img19/729...ting019.th.jpg

Both lights are on the same rechargeable battery pack.

Of course it's important that they see you, but the ones coming up from behind are more likely to see you anyway, since they're looking straight ahead most of the time. At intersections though, a quick glance that left- and right-turners often limit themselves to is not always sufficient. Collision stats appear to confirm this.

I don't ride with my lights on in the day time, actually with summer now approaching I took my lights off , I wear an orange coloured messenger bag, which is very visible in the daytime. If any driver can't see me then they are stupid and ignorant.

Never underestimate the ignorance and stupidity of people. :thumb:

True but it's not just an issue of seeing me, it's an issue of seeing me as soon as possible so they can start evaluating the situation and adjust speed if necessary before they are next to me. I understand your point about intersections of course.

Yes, both, always.

I run my dinottes (200, tail , and amber) on blinking mode. Now that picture of the bike headlight isn't moving. I see people in germany who eave their dynamo running, very low watt, and I see them a very long way off. I notice them far sooner than I would just the bike. So my dinottes blinking, making the car paint and traffic signs all around my flash when it's even a little cloudy, must be helping! I actually think people slow down to assess the flashing light situation. I also wear a high viability vest. It's simply worth it when your out there everyday. I also bike to live longer, not shorter!