I just switched over to the Nitecore brand of flashlights and headlamps and I LOVE the Nitecore products! These 18650 batts last much longer than I had anticipated and I’ve always got a backup on hand. I bought the D4 charger last month along with 2 more of the 18650 batts, so now I have a full bank charging at all times. The HC series of headlamps are amazing and super durable. I bought the HC50, HC60 and HC90 earlier this year and I love them. Killer customer service, too...thank Brian!