Hi, I have this headlamp now since October 2011 and am still enthusiastic. Grade now during the winter months it is my constant companion. I run several times a week in the evening partly over hill and dale. In rain, snow completely Flung. The lamp has been through everything, no problems with rain, the lock is secure at all stages and the luminous efficiency is already in the simple stage quite sufficient. So I can only recommend the lamp. To use the lamp with batteries fill, no problem. How long will a charge batteries I can not say exactly, but for a winter season with 2-3 uses per week with over an hour of operation in various lighting levels it was good enough. I would buy me at any time.