I love cycling at night, but I also like living, so when I ride at night or in the rain I always have a Planet Bike Superflash Tail Light on my bike. This tail light can run up to 100 hours on just two AAA batteries and the half-watt LED light can be seen from up to a mile away.
The Superflash has a steady mode (light on all the time) and a unique flashing pattern that really helps motorists see you (this is the mode I always use). Last fall I went for a long off-road ride at night but I forgot my water bottles, so I phoned my wife and asked her to bring them to me at a park I was going to pass through later. My wife said that when she turned down the road going to the park she saw my flashing lights from over 3/4 a mile away and thought it was a police car in front of her! I now own four of Superflash tail lights (one for each of my bikes).
From personal experience I can tell you that you should never look directly into this tail light (you will be seeing red spots for at least 15 minutes). Considering how bright the Superflash is it is an incredibly compact unit, measuring only 2.75 inches tall, 1.5 inches wide and 1.5 inches deep.
You can mount the Superflash on your seat post with the included mounting bracket or clip it on your seat bag. Over the past ten years I’ve probably lost a dozen tail lights (from several manufacturers) when they fell off my seat bag after hitting a bump. Though I’ve not had this problem with the Superflash I now secure my tail lights to the seat bag with a simple cable tie (see the photo above). Cable ties are really cheap and you can cut the cable anytime to remove the light (I use cable ties for all sorts of things on my bikes). Planet Bike claims this tail light is weatherproof. I’ve used the Superflash in both rain and snow storms and in temperatures down to zero without any problem. As you probably know, the battery life of any light will be considerably shorter when the temperature drops below freezing.
The Planet Bike Superflash has a retail price of $30, but you can find in on Amazon.com for around $25. I believe this is a very fair price for a quality tail light. You could buy a cheap tail light for about half the price, but it is truly a case of getting what you pay for. If you choose to take the cheap route please remember to always carry your driver’s license and an organ donor card (the driver’s license is needed to help the police identify the body).