Do remember to recycle batteries whenever you can.You can recycle batteries at Batteries Plus, or do a Google search for a place in your town.
There are a few light movements to provide solar-charged LED lights to kids in Africa so they can actually do homework at night with these lights. These lights are often inexpensive, and effective.
- LEDs have a negative and positive leg.
Do not mix them up or your LED will go "poof"!Actually you can mix up the legs, and it just won't work. But if you apply too much voltage, then the LED will go "poof". This page has an image showing you that the LED has a flat side, which is the negative side.
- If you add a switch, you can add it anywhere in the circuit to cut power.
- If you get a brighter LED, 1 watt or larger, it will generate a lot of heat and you might need a heatsink.
LED flashlight runs on dead batteriesHere on Etsy.
DIY LED lights, beginner- 9v LED light. This one is easy because it tells you exactly which resistor to use. And 9v batteries are sold at the US Dollar Tree.
- How to choose resistors for an LED light. Nice clear picture.
- Another page with a simple drawing of a basic LED circuit, designed for beginners.
- The LED throwy is one of the simplest LED projects. It is just an LED taped to a coin cell battery, taped to an optional magnet. It has no switch.
More fun with LEDs- The top 30 LED projects includes: LED bench, solar powered tree decoration, LED ping pong balls, LED chess set, LED swing, and more.
- The Instructables LED page, a collection of LED projects. One can use those UPS batteries for all kinds of things, especially because they are rechargable.
- Glowing mushroom log from Yukio Takano.
- LED Lights for beginners. From Instructables. This is a good one which shows you how to calculate resistor values. Resistor values vary depending on how much power is in your power source. A 9v battery (9vdc) requires a different resistor than 2 AA batteries (3vdc).
- 9v LED light "lamp" made from credit card plastic parts.
Simple commercial lights and conceptsSince Africa is leading this movement, sometimes I call these "African lights".
- LEDAfrica.org shows some interesting lighting and battery concepts.
- The Blocklite sits on a 9v battery. It has high and low modes.
Here's a variation on the 9v blocklite, the Pak-lite.