I have no problems with my USB rechargeable lights. I have a NiteRider MiniNewt 600 and I get the run time listed on their website(1.5hrs at max brightness). Even after running it for 1hr 15min in full brightness, there is plenty of charge for the next morning(full sun) going in the blinking mode(1hr15min ride). They also informed me that replacement batteries for $25 and could be done at home. I have a Cygolite Hotshot rear light and I charge it maybe once a week(about 12.5hrs of use), but mostly just to be safe. I have had more people ask what kind it is then any others I have used. I have a ton of the USB cables already for other devices. I get to work, plug my light, and helmet camera in while I am at work. When its time to go, they are all charged up and ready to get me home. Rinse repeat.