My Little Man got a Nintendo 3DS for Christmas and I was thinking about what would happen if power went out and he wants to play. The power cord that came with the 3DS was made just for it and was just for wall plug. So I first got an adapter for it that makes it to be able to use USB for power. This made it where I could then get a Solar Power USB Charger , plus we already have our RAVPower 15W Solar Charger with Dual USB Port (Foldable, Portable, iSmart Technology) that I can use for my Kindle and our phones , etc.
The other item in the photo is a Solar 11-in-1 Battery Charger that I just bought a lot of AA and AAA rechargeable batteries for to use with other handheld devises and radios. Always prepared. I keep all of these in a small faraday cage that I made with each item in Antistatic Bags. I made a cheap faraday cage that I just made out of a 18 gallon rubbermade tote ($5.00) and 3 rolls of aluminum foil. ($3.00) Each item kept in the antistatic bags. I tested it out with my cell phone. I hope that is all that I had to do. I placed it in there on and tried to call and text myself and it did not go through. I keep my kindle and some other small radios, handheld scanner, walkie-talkies, and more in it.