Batteries are an obvious necessity in outdoor adventure filmmaking. On quick, short trips it’s not a huge deal to simply take along a few extras and make sure they are all fully charged before you head out the door. On longer trips however, you might have to think harder about your power supply.
Cozy batteries last the longest. They need to be kept at the “just right” temperature, not too hot, not too cold, to have the longest life. In hot weather, keep them in the shade, and in cold weather, keep them close to your body.
Energy conservation is a key practice when shooting your film in the backcountry. This is where something like a shot list comes in very handy. You get the shots you need and nothing superfluous. Shooting willy-nilly will not only give your editor a harder job, but it will sap the juice out of your batteries even faster. “But I have a solar charger!” you say with confidence.
Solar chargers are amazingly expensive for my budget, but if you have one great! There may be a few issues though, namely, what if it’s not sunny out on the day you need to charge everything back up? Also, it takes a long time even in direct sunlight to recharge batteries with a solar panel.
Goal Zero makes some amazing products to remedy the need for recharging in places that have no electricity. But as amazing as they are, again, you gotta plan for charge time and for a heavier pack.
Most solar panels require an AC/DC converter to get the right current for your device and/or a battery pack for which the solar juice is stored. Those battery packs can take up to 20 hrs to recharge, depending on the panels you use, and then you charge your batteries off that battery.
Weight-wise, you are probably looking at an addition 4 lbs in your pack and unless you hired a Sherpa, that’s a lot of extra weight with your food, water, camping gear, and…oh yeah, camera gear!
Not trying to dissuade anyone, just putting the details out there. I think on longer adventures the best combo is efficient battery usage and either a solar charger or buying extra batteries. You may have to decide the cost-to-weight ratio for buying and bringing a few extra batteries vs. buying and bringing a solar charger.
Ultimately it’s a balancing game with your gear. Minimalism is the chant of some, while I know others who have suffered a great deal to haul a shit-ton of gear up a mountain!