I did a 5 hour hike on the AT at night with headlamp the day after I received it. I used the low power mode, not knowing how long the batteries would last on the high setting. The lower setting was adequate most of the time. The following night I used it for another two hours of night hiking as well use around the camp. The batteries lasted through all of that just fine. The ambient light accessor
This review was written in the old system and had content requirements that are different than reviews written today.