Todays smartphones are out of power within one day, but what if you're having a long day and need to make an important call at the end of the day? That is where a pocket battery charger comes in handy.
These are commercially availible, but at a cost. DIY will make it easy and cheaper. Also it's more fun to make your own (unique) model.

Step 1: Materials

- Case for your charger
- USB-boost module(see below)
- Battery holder
- Charged battery (voltage depends on USB-booster)
- Wires

- Switch

The case is to your choice, should be clear after reading this 'ible.(Note: tins are conductive, so prevent shorts by insulation with paper or tape)
Just make sure the battery and boostcircuit fit nicely in or on the case.

The USB boost module the item you'll probably wont have near you, so you'll have to order it.
At Ebay
I bought mine at our University electronics store for 2 euro's.

Note to IPhone users:
An USB-connection has 4 wires: V+(5.1 volts), V- (earth, 0 volts) and 2 other wires. Iphones are the only phones who check the other 2 wires for a certain voltage to know how much current they can drain ("how fast they will charge"). It might be possible that these circuits don't add that voltage to those wires, thus preventing the IPhone from charging.
Can you use a 9 volt battery instead of the battery pack or is that too many volts
The input should be around 1-5 volts, as it can only increase the voltage. 9V might damage the circuit. If you must use a 9V pack, you'd want a step-down circuit. If you want to use this circuit, find appropriate batteries.
Great instructable! <br>I have a rather silly question, would it matter if the battery holder (and used for the charger) is AA or AAA? I've seen a lot of instructables similar to this using AAA. <br>Thanks in advance!

About This Instructable




Bio: I'm a Applied Physics student from the Netherlands.
More by Sjoerd X:Pocket Phone charger with booster module ($2 or �2 total) 
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