What? A solar panel review on a motorcycle blog? Yes, you have read correctly. Whether you realize it or not, your bike runs on fuel, air, and spark. Take one away and your fun is over. So electricity is pretty important to having two-wheeled adventure. So what will you do one day 100 miles from town when your battery goes kaput? Most modern touring bikes do not have kick starters anymore, so good luck making that electric start turn that crank over. You are either going to need a jump ( you did ride with a buddy and you did bring jumper cables right?) or you are going to have to find an alternate power source. That is where portable solar power comes in.
The technology for solar panels just keeps getting better and better. More and more watts of power are coming from smaller and smaller panels. I recently invested in the Goal Zero Goal 10 plus solar kit. Its a compact rugged fold-able kit that packs away in my trunk or pannier easily. The panels have enough power to charge my drained cycle battery in just a few hours in direct sun. It also comes with a built in battery so that even when it is not connected it can store up its own energy for use later (no the internal battery is not big enough to start your bike from!). The kit comes with a double AA (and AAA adapter) charger, cigarette lighter adapter, and plugs for micro-usb as well. So besides charging up your cycle battery in a pinch, it can charge up your gps, cell phone, go-pro, flashlight, etc. as well.
I have found that the panel charges much faster than older panels I have tried in the past. The case it durable and the accessory pouch is perfect for storing all the cables. Overall I am very happy with the purchase and the piece of mind the alternative power source provides. Reviews on popular internet stores indicate my experience is not abnormal. Hunt around and you can find this product for $100 or less.
Last summer I was moto-camping with another rider and he left his iPhone charging on his bike’s 12v outlet all night. By morning the bike would barely turn over. Not good. The iPhone had drained the cycle. A portable solar panel would have been a much better solution. So keep this product in mind as you plan your next trip. It might just turn out to save the day.
Minnesota Adventure Riders 
I got one of these for Christmas and have had great luck too although I am not familiar with how to attach it to my motorcycle battery. I do use it to charch my phone, charge my ipad, and anything else I have that connects to a USB cable. If nothing needs charging I keep the rechargable batter plugged in and I will be able to charge something when the sun goes down!!