There was a box of solar path lights on sale at Target. Something like $30 for a 10-light set. I picked up a set and stripped it for parts.
Step 1: Basic Units
There are two types of lights in the set: eight path lights and two spotlights. The path lights have their own, built-in solar cells. The two spotlights have a single, larger solar cell.
Step 2: Path Lights
Each path light contains:
- AA nicad
- white LED
- solar cell (roughly 2.5V no load)
- charging circuit
- AA battery holder
The charging circuit consists of a couple diodes, a couple resistors and a capacitor.
Step 3: Spotlights
The spotlight set contains:
- 2 white LEDs
- 2 AA nicads
- a battery holder
- a slightly more sophisticated charging circuit
- a larger solar cell (3V no-load)