## Introduction: Free Energy ? Charge Your Mobile Phone With a Hand Crank Generator

Problem : Mobile Phone always RUN OUT OF JUICE

Mobile phones have become an essential of everybody’s life. Browsing, gaming and messaging, you are spending every minute with your phone.We are entering the era of Nomophobia, No Mobile Phone Phobia. You can leave your wallet at home but you can’t live without a phone.

One of the greatest pain points of using a cellphone is the battery. You can’t live without your phone while your phone can’t live without battery. Therefore, varies power bank solutions are rolling out in the market. But what if your cell phone and power bank are running out of juice at the same time.

Imagine you are sending an important email to your client and the phone is dead. Imagine the apocalypse happens, zombies are everywhere. Imagine you are Bear Grylls and try to survive in a no-man island.

Solution : A Portable Hand Crank Generator
In case of emergency, like Bear Grylls, we need a battery charging solution that is robust, accessible and portable. For god’s sake, coin battery and potato battery is apparently not an option.

Therefore, I decided to make a hand crank battery charger. Using the human-powered generator to create electricity via motion and forces have already got a long history.

Anyway, let’s get started. Here are the major components: a servo motor, a diode, a polarised capacitor and a 5V boost module.

## Step 1: Convert the Servo Motor to a Hand Crank Generator

Disassemble the servo motor. Desoldering all the wires on the board. Solder the wires and motor together. Also, remember to remove all the locking parts in the gear. After that, you can reassemble all the pieces together.

## Step 2: Solder the Boost Module, Diode, Capacity, and Server Motor Together and Turn Them Into a Complete Circuit.

A diode is very important in this circuit. Since the hand crank mechanism can go either clockwise or anti-clockwise, the diode can prevent the current flow in a wrong direction.

A boost module is needed because the servo motor can only generate 1–3 volt which is far from the 5-volt standard to charge our mobile phone.

## Step 3: 3D Printed Case

Finally, a 3d printed case is needed to house all the electronic components together.