2. Solar LED Garden Lights made with discrete components.
* Schematics may differ slightly.
CDS, on all circuits, is a photo resistor (light-dependent resistor).
Interestingly, they have almost same circuits.
Very old, and looks like home made.
3. Solar LED Garden Lights (direct powered LED).
The simplest. Siemens Pathmarker, model 16953:
In case where two rechargeable batteries and Yellow LED:
One 3.6V Li-Ion rechargeable battery and overcharging protection:
4. Simple dual-mode Flashlight
Emergency Flashlight has two options. ON constantly or short flashes every 0.8 second.