The device has an amazing economy of design with only four components including the solar cell and the LED. The final component is a small inductor that forms part of the boost converter to keep the LED lit as the battery voltage falls. The chip switches at 580kHz, and produces a 3.2 volt supply.
If you walk the aisles of a dollar store one constant that you will see worldwide is the Chinese solar lamp. Your dollar gets you a white LED behind plastic, mounted on a spike to stick into the ground, and with a solar cell on top. It charges in the sunlight during the day and then lights the LED for a few hours at nightfall.
Battery settings too low 8.5.6. PV voltage too high 8.5.7. Reverse PV polarity 8.6. Batteries are undercharged 8.6.1. Insufficient solar supply 8.6.2. DC load too high 8.6.3. Battery cable voltage drop 8.6.4. Temperature compensation setting incorrect 8.6.5. Temperature difference between solar charger and battery 8.7. Batteries are overcharged