Either way you are going to have to be packing extra batteries.
Now is a good time to figure out just how long batteries are going to last in you headlamp. I have a rechargeable one that the batteries will last 14 hours before they need replacement. And I have a disposable battery one that will last well past 20 hours on one set of batteries. I like the rechargeable one best just for the light that it puts out. You also need to ask yourself how long are you going to need a light? If you are sitting around a campfire there is no need of one except when you wander off into the dark and the first thing in the morning. Also do you plan on hiking further back into the hills when it is dark or are you going to wait until it starts to get light?
Also remember that what you take in you need to bring back out for proper disposal, so lighter is better.