Extending the run-time of a solar garden light.

In countries like the UK where we have a lower than average amount of sunlight (mainly due to cloud coverage), the performance of solar garden lights tends to be optimised for the lower light exposure.
Some lights tend to run at higher current though, and while being brighter they don't last long at all when it gets dark.
Most of these lights use a dedicated chip for complete control including charging, light sensing and driving the LED from a lower voltage cell by stepping the voltage up with a pulsed inductor.
By changing the value of the inductor you can change the current and intensity of the LED. Strangely, increasing the inductor vlaue reduces the current. So a 47uH inductor will make the LED bright, while a 470uH inductor will make it run at much lower current.
The dollar-store lights tend to use a 470uH inductor so they can skimp on the size of the solar cell and battery.
In this video I change the inductor in a light to reduce the LED current and get a longer run-time at night.

Datasheet for the XD 5252F chip in the rather unusual form of a JPG image.
http://www.xingdong-et.com/wp-content/uploads/2013/05/TO-94-XD-5252F-1.jpg

Видео Extending the run-time of a solar garden light. канала bigclivedotcom