I live on a river and built a campsite on an island across from my house (the dog loves it). I bought a deep-cycle marine battery but am getting too old to lug it in and out of the canoe for charging. So I got this little panel and, so far, have not run out of juice. And it's cheap enough so if someone steals it it's no big tragedy. I run a laptop, TV, fluorescent light and charge my cell phone. I even have a 12v car-vac to clean the sand out of the tent.Of course, I'm not there 95% of the time so 5 watts is probably adequate. And I don't have to worry about overcharging. I screwed it to a big log in pretty open sun. So far, it has survived, even some small hail.BTW, I use the power cord from an old vacuum cleaner and a 4-way 12v splitter to distribute power from the battery.