Now this looks like a great Idea, and something that I fancy giving a blast, however I'm not going to pay £8, soooo I've got my eyes on butchering one of my solar garden lights and have already found myself a donor bottle for this project. Coming soon, BG's homemade bottle light ;)
Read this guys review.......
The LightCap 200 turns any of those ubiquitous wide-mouth water bottles from Nalgene or Camelbak into a solar lantern. The LightCap is, as its name implies, a replacement cap for a water bottle, but with four bright LED lights on the underside and a small solar panel on top. Fully charged (about 12 hours in direct light), the LightCap 200 will yield an amazing eight hours of light, which is more than enough to sustain most camping trips or outlast a power outage. More on my time with the SolLight LightCap 200 after the jump.
I've often cursed the waste, and weight, of fuel or battery-powered lanterns. So, I was thrilled to try out the LightCap 200 on a recent backpacking trip. It weighs next to nothing on its own, and since I had to carry full water bottles in my pack anyway, I had no extra weight in the form of batteries, fuel, or lantern. Since the LightCap 200 is waterproof, there's no problem screwing the cap onto a full water bottle. However, I strapped the LightCap 200 to the top of my pack for the hike in, to give it some time to charge in full light.
After using the light on the first night, I only had to leave it in the sun on Day Two and it was charged up and ready to go the next night. Due to the LEDs, the light is rather focused, rather than diffused like a regular lantern, but it provided ample light for food prep and a card game. Even better, I had no fumes or fire hazard to contend with while reading in the tent at night.
Click on the tittle of this post to see a video of the lightcap in action.....