Knog Blinder 4V
Rechargeable lights are booming right now, and with good reason. Brighter than ever, with batteries that hold a charge for more than a single ride, and easy USB power interfaces, the latest crop of commuter lights are a far cry from the comparatively clunky and dim lights we were all using just a few years back. I reviewed the square format Blinder 4 a couple of months back, and have spent the summer running the pictured vertical format Blinder 4V as my go-to rear light.
The light is bright, the LEDs are rated at 44 lumens according to Knog, and I tend to get 3-4 hours from a charge out of the brightest, most frequent flashing modes. The attachment system is one of my new favorites, easily moving bike-to-bike or into my pocket for extended lockups and showing no signs of premature wear after months of solid use. Like the other Blinders the 4V is completely waterproof (I ran it through a charge submersed in a glass of water) and recharges with a flip out USB plug. Perhaps my only complaint about these lights is that the USB plug can be hard to use depending on your computer or USB hub configuration — luckily USB extension cords are relatively inexpensive, though it would be nice if the light came with a short one to make charging more convenient.
In use I love the extended button push needed to turn the Blinder on/off, as it both prevents accidentally turning it on in your bag but allows you to turn it on or off on your bike without having to cycle through all of the modes. The light remembers which of the 5 modes (steady, fast flash, flash 1, flash 2, eco-flash) the light was in when switched off, and with up to 50 hours of run time per charge in eco-flash mode gives you some control of battery usage. The light is a mere 39g and retails for $45, see more or order direct at the Knog Blinder page.