Solar Bag recharges anything that can connect to a USB port. Solar energy is collected and stored in the battery pack while not in use. I use it to keep my power hungry cell phone and ipod running all day or in an emergency. You can buy these online for a few hundred bucks, but this one cost about $100 if you DIY.
The solar bag consists of a flexible solar panel, rechargeable Ni-MH batteries, and a few electronic components to tie it together.
The solar panel is a PowerFilm P7.5-150 producing 7.2V and 200ma in ideal conditions, more than enough to charge three nickel cadmium batteries.
Two circuits are used in this design. The first circuit employs a MAX639 step-down switching regulator to transfer all of the solar panels energy to the batteries as efficiently as possible. The second circuit uses a LT1302
All of the circuitry can be placed on a project board and fits into a small space. I found some garden solar lights on liquidation at Wallmart and it was easy to remove the existing circuit and incorporate my board into the design which evidently gave me a second solar panel which I can take out and place in a window when I'm indoors. With a full day of sunlight, enough energy is stored in the batteries to completely recharge my power hungry cell phone and ipod and I feel good about using renewable energy whenever I can.
No comments:
Post a Comment