I bought one of these last fall Hotest 1800 Lumen CREE XM L T6 3modes Bicycle Light LED Light Flashlight + 4*18650 battery pack & Charger-in Bicycle Light from Sports & Entertainment on Aliexpress.com | Alibaba Group for my winter bike.

Used it all winter, about half an hour a day on average. It was plenty bright at the lowest setting, worked flawlessly and got about a month/charge out of the battery pack. It comes with everything - charger, several mounting straps and a strap so you can wear it on your head.