You Can Turn Soft Drink Bottles Into Handy Solar Lamps

Solar lights are a popular garden decoration. Of course, they’re available cheaply from most hardware and garden stores, but if you’re more of the DIY type, you might like to build your own. [opengreenenergy] has done just that, using recycled materials for a cheap and simple design.

The design was inspired by the Moser bottle, which is a water-filled bottle used to diffuse sunlight into a room during the day. Instead of sunlight, however, this design uses an LED to provide the light, for decorating a garden or for use when out camping or traveling.

In this design, a solar panel is used to charge a lithium-polymer battery during the day using a LP4060B5F charge controller IC. It’s paired with a AP6685 battery protection IC to ensure the battery is not overly discharged or otherwise damaged in use. When the solar panel stops putting out power when it gets dark, the LED is automatically switched on. It can be set to a low or high brightness to provide more runtime or more light as needed.

All the circuitry is wrapped up in a neat 3D-printed case that allows the hardware to be screwed directly on top of a regular soft drink bottle. Paired with some water in the bottle, and perhaps a little bleach to stave off algal growth, the result is a handy, portable light that also has enough mass to avoid it being blown over easily.

It’s interesting to compare the design to commercial versions that aim to pare costs down to a minimum. Video after the break.