I teardown a $10 motion activated solar garden light from Kmart in Australia.
I bought this product to solve the problem of not being able to locate my house key on the key chain at night. But I couldn’t resist tearing it down to discover the electronics that make it work.
Unlike most solar garden lights, that use Nickel Cadmium (NiCd) or Nickel Metal Hydride (NiMH) battery technology, this unit is powered by a single LiFePO4 (Lithium Iron Phosphate) cell. These cells produce a nominal 3.2V, which means that with a bit of hacking this unit could probably be used to power a microcontroller such as an Arduino at 8MHz.