Solar lamp is a popular garden decoration. Of course, most hardware stores and garden stores can buy them cheaply, but if you prefer DIY type, you may want to do it yourself. [opengreenergy] has done this, using recycled materials for cheap and simple design.
The design was inspired by the Moser bottle, a water filled bottle used to diffuse sunlight into the room during the day. However, instead of using sunlight, this design uses LEDs to provide light for decorating gardens or for camping or travel.
In this design, the lp4060b5f charging controller IC is used to charge the lithium polymer battery during the day. It is used together with ap6685 battery protection IC to ensure that the battery will not be over discharged or damaged during use. When the solar panel stops power supply when it is dark, the LED will turn on automatically. It can be set to low or high brightness to provide more or more light as needed.
All the circuits are wrapped in a neat 3D printing box so that the hardware can be screwed directly to the top of an ordinary soft drink bottle. Plus some water in the bottle and maybe a little bleach to prevent algae growth, the result is a convenient portable lamp with enough quality to prevent it from being blown down easily.
It is interesting to compare this design with a commercial version designed to minimize costs. Video after break.