ok here is the problem:
Imagine that you have 2 celular phones, you know they have different chargers, suddenly your favorite celular phone charger
explodes, dissapear or even if you connect your charger to your favorite phone, the phone says is not charging your battery is diying! and you NEED to use your fav phone because it haves the photos, videos etc that you want to share or is just that
YOU NEED TO USE YOUR FAV PHONE IN THAT MOMENT AND YOU CANT BUY A NEW PHONE CHARGER AT THAT MOMENT
or maybe you just want to charge a 3.6 volt batteries from disposed celularphones.
here is how:
you will need:
2 cell phones
1 working cell charger
1 rubber band
1 male header pin with 3 pins
As you can see in the photo you have 5 volts of energy directly from the charger connector, you cant use that volt power because your cellphone batteries works with 3.6 volts.
Also you cant use the charger directly because cellphone companies loves to make you buy a special cellphone chargers with weird connectors.