LightCap by Simply Brilliant (names say it all)
by Warren McLaren, Sydney on 11. 2.05
I like to spend whatever free time I can muster in the outdoors, but generally go fairly lightweight, so might never carry the LightCap myself. But that doesn’t mean it isn’t a very bright idea. Imagine a 1litre (32 oz) polycarbonate wide-mouth drink bottle, then fit a solar cell into the exterior of the cap and a energy efficient LED light in the underside. Charge up the solar cell during the day, and at night you have a virtual fluorescent light for camp. If the photos are accurate, it looks like the light refracts through the water, making the light broader spreading that it would be on its own. If you can manage 12 hours of direct sunlight the LightCap will provide 8-10 hours of illumination (or more than 16 hours if you switch it to the energy, and night sight saving, red LED mode. The rechargeable (and replaceable) Ni-Cad batteries are said to last through 300 cycles. The weigh difference over a similar, yet ordinary unlit,, drink bottle is 4.6 oz (130g). This is about the same as small LED headlamp, so there is no overall weight saving for gram counters. But there is no disputing the cool factor of these waterbottles. Set a LightCap going after dark and your tent-site will probably attract other campers, like moths to a flame. ::LightCap
Cadmium is highly poisonous. i wouldn't take the chance of a leak in the battery casing.
On top of that, polycarbonate is one of the poorer choices for food-safe plastic.
I'm torn about this product. It's a fascinating idea and a very cool implementation. As an avid backpacker, I would find this product very useful since I wouldn't normally carry a lantern into the backcountry, but always like some additional light by the camp. However, lexan and transparent nalgenes are toxic:
http://www.grist.org/advice/ask/2004/08/02/umbra-bottles/index.html
I carry a water bottle to work every day and I've recycled my lexan bottle in favor of Nalgene's regular old translucent #2 plastic bottle. I guess there would be no need to carry a lamp bottle around to work - only on camping trips really - so the toxic exposure would be minimal, but I thought fellow Treehuggers might be interested.
Regarding Robert's legitimate concern about the battery, the LightCap website notes, "___ rechargeable battery pack are fully sealed outside the cap, making them totally safe and waterproof. There is no possible contact with the contents of the bottle."
And yes, there have been many concerns expressed about the leaching of bisphenol-A (BPA) from polycarbonate containers, and I neglected to add this caveat. (Similar widespread community fears were once held in relationship to aluminium saucepans being a cause of Alzheimer's, but this remains unsubstantiated). And it seems that non-leaching polycarbonate is available, as indicated by these bottles from Real Goods.
This is not to say that neither of these concerns are valid. Am just wary of 'throwing the baby out with the bath water.'
As I noted recently, regarding the diesel motorbike, TH is not about endorsing any featured products as the perfect end-solution, rather as directions for the path forward.
We (Fuego Diego, the San Diego Burning Man group) built a bunch of these ourselves - but a lot more stylish - over a year ago. With a UV LED and a neon-colored bottle, they really glow.
http://www.fuegodiego.com/gallery/lightedgoblets
http://www.fuegodiego.com/gallery/lightedgoblets/DSCN3445
Check out the design from Guyot Designs, I think it's much nicer:
http://www.guyotdesigns.com/products/firefly/firefly.php
A UV version would also act a a water purifier wouldn't it? A separate purification mode in addition to the energy saving mode would be cool.