The DIY Solar Charger

by John B. Carnett John B. Carnett

It's a dark and stormy night–too dark. Your home has lost power. Fortunately, you've got a fully charged power plant, built from an inexpensive solar panel and a rechargeable battery. Eight hours of sun will produce enough juice to watch An Inconvenient Truthtwice–on a portable DVD player. You can even find inverters that will turn the station into an AC outlet. Add additional panels and batteries, and you could power the margarita machine and the flat-panel too.

Build a Solar Power Station

Cost: $150
Time: 3
Hours
Easy | | | | |
Hard

Parts

• A. Bamboo scraps ($7; local flooring store)
• B. Sunforce five-watt, 12-volt solar panel ($48; amazon.com
  )
• C. Quarter-inch plastic mono plug
  (50; allelectronics.com; #SPH)
• D. Solar DC charger controller for solar panel ($28; allelectronics.com; #SCN-2)
• E. 12-volt 12AH rechargeable battery
  ($36; allelectronics.com; #GC-1214)
• F. Four feet of 18-gauge wire
  ($5.65; allelectronics.com; #WRB-18)
• G. Two female terminal disconnects
  (23; jameco.com; #109112)
• H. 15-amp DC panel meter
  ($12; allelectronics.com; #PMD-15A)
• I. Reese "Towpower" connector
  ($9; local auto-parts shop)
• J. Cigarette-lighter "Y" adapter
  ($3.65; allelectronics.com; #CLP-Y)

Step-by-Step

1. Build the case
   
   To make a cheap, eco-friendly case, we glued up bamboo flooring scraps (bamboo is fast-growing and renewable). Cut holes in the box for airflow and easy carrying, and build frames to hold the DC charger controller and the battery.

2. Add the panel
   
   Attach the solar panel at an angle roughly equal to your latitude for optimum charging (go to census.gov/cgi-bin/gazetteer to find yours). Add a tilt bracket for additional adjustability. Leave space underneath both the panel and the controller for airflow.

3. Wire it up
   
   Snip off the cigarette-lighter plug and solder the quarter-inch mono plug onto the "Y" adapter. Insert the mono plug into the 12-volt output outlet on the controller. Connect all four power leads from the battery and the solar panel to the controller's input terminals. Hook up the meter to the controller's input terminal for the solar panel. For more power, attach additional solar panels, and add extra batteries-but don't exceed the 12-volt rating of the controller.

4. Connect the battery
   
   Test all connections with a volt-
   meter before attaching the battery.
   Connect the red wire with a female-
   terminal disconnect to the battery's
   positive (+) terminal, and connect the black wire to the negative (â€) terminal. Place the station in the sun, and plug something in.