Duration: 6:18

An emergency battery charger for your mobile phone comes in handy, but it's not the ultimate solution; once it's dead it's useless (what a waste). If you want to really get off the metaphorical grid, you can follow the steps in this video to construct a more robust circuit that will not only bail you out of an inconvenient situation but also recharge in between uses. The simple addition of a low voltage solar panel and rechargeable batteries makes this possible. Enjoy! Parts: 4 x NiMH AAA Batteries 1 x 4 AAA battery holder 1 x Small PV (photovoltaic) solar cell 1 x Diode rated min 5V 500mA 1 x USB cable or cable of your choice Tools Required: Soldering Iron Lead Solder (the kind with flux core is best) Heavy Shears Wire strippers Electrical tape Tips: Solder in a well ventilated area on a non flammable surface ALWAYS WEAR EYE PROTECTION Check the circuit polarity before final soldering