>>1218647The technology is not really there yet for backpacking, IMO, if you are asking about practicality. In MOST cases, you're going to have a more reliable, lighter and less bulky system to just bring extra batteries (AA's for headlamps) or a "battery pack" style charger that you pre-charged at home, if you really need to use your smart phone that much. Now outdoor living is another situation, but you asked about backpacking, which I define as camping for only a FINITE period of time.
These solar panels really do excel for boat trips, though, when you can rely on at least a couple hours, potentially many hours, of down time every day when you know you will be basking in the sun.
On backpacking trips, you're not always able to get them out and point toward the sun during the daytime. You might be hiking under trees or it might be cloudy when you stop for your lunch break. The setting and rising sun has a lot less charging power on a solar panel than mid day sun. It would typically take one or two hours of down time in the middle of the day to wait around for your smart phone to get charged up, and that's IF it's sunny. Al Gore and Michael Moore like to omit this fact, but solar panels don't produce energy when it's cloudy or at night.
Hanging them on the outside of your backpack is really not viable, even though the woman in the photo in the OP is doing that. She's a dumb thot, though. That shit will be swaying around, getting snagged on plants, blocking access to her backpack and generally getting in her way. And if you notice, only one of the four panels is facing the sun. The rest are going to get indirect sunlight at best, and since these things charge with such a low amperage, she's not going to get much charging done throughout the day like that anyway. If she's hiking through the forest, nothing will get charged and the panels will be extra weight ONLY. Hence, it makes more sense to just bring extra batteries to last you the duration of your trip.
