In this article, I will take apart a Li-ion alternative to the classic 6F22 9V battery. This battery is a Chinese 9V/500mAh USB rechargeable Li-ion battery (sold under the brand name infinite). The ...

Up to now, this battery level indicator design was limited to 12 & 24V applications. In past circuits, the use of fixed resistors greatly simplifies setup. However, fixed resistors resulted in ...

Volta’s pile — the first battery — was little more than silver and zinc discs separated by paper soaked in salt water. A classic classroom experiment is to build a pile from copper pennies, tin foil, ...