Hey, this is Ben, an indie maker from Hong Kong. This is a weekend project for fun and learning. I hope you also get some inspiration from this article.

### 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 one, 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 on the gear. After that, you can reassemble all the pieces together.

Step two, 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.

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

### Conclusion : No Free Energy and Stop Phone Addiction

Wa la, there you go. A hand crank mobile charger that can work in the apocalypse. Of course, you can charge your tablet. You can charge a LED stripe or even a GoPro.

This is not a product that can use on a daily basis because it takes at least a several hours of cranking to charge your phone to 100 percent. This is just a project for fun and learning. So, please save your crank charger until the judgment day. To prevent your phone run out of battery when you need them, why don’t you stop your phone addiction, say stop the unnecessary refreshing of your Instagram feed.