Portable Mobile Charger




About: I am a Biomedical Engineer

Charge your mobile any where using a 9V battery or any other portable battery with polarity protection.

Step 1: Materials

The materials we need are:

1- On/Off Switch.
2- IC 7805.
3- 9V battery Cap.
4- 47uF Capacitors X2.
5- 100nF Capacitor.
6- Red and Green Leds.
7- 1N4001 diode.
8- 100 Ohm, 470 Ohm Res.
9- Female USB.
10- Plastic Case.
11- Fiber board.

Step 2: The Schematic

You can print this picture in the real size and put the elements as shown and then connect the lines with solider.
put don't connect the leds,usb connector or the switch.
wire them up like the picture avove ( use one color for positive and other color for negative ).
For the USB make sure of the polarity and connect the Positive to pin 1 and negative to pin 4 (see the picture above)

Step 3: Connecting Everything Together

Drill the plastic case to fit the leds, the switch and the usb connector as you want.

Step 4: Finishing

You can connect any a 9V battery using the cap.
or you can connect and dc power supply (like batteries) from 7V to 20V.
I'm using a 12V battery.
Once you connect the power supply the green led will light but no voltage on the usb connector.
When you turn on the switch the red led will glow and the charging will starts using a USB cable.



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7 Discussions


2 years ago

Use boot/boost converter instead of 7805 !, 7805 cannot Handel mobile changing and will also get heat up like hell

Anirudh Ralhan

2 years ago

That's a really easy but cool DIY power bank :)


2 years ago

Yes it works, but what a waste of energy ! 12VDC to 5VDC, 1.5V for the regulator, you lose 5.5V multiply this with the intensity and you'll get the power lost. It's far better to use a DC/DC converter which has about 80% of efficiency. Another point concerns the first Led, it eats 0.2A with the 50 ohm resistor, I think a 470 ohm would be fine.

2 replies
Eng Adib Ghannamrafununu

Reply 2 years ago

ofcourse buddy, using a DC/DC converter would be much better (like using the IC 2576-5V) but it would be more complicated cause you have to use a coil and you would need more space on the board.
and I wanted it to be simple.
and for the resistor it is 500 Ohms not 50 Ohms and I used 470 Ohms.
and thank you for your review ?


Reply 2 years ago

Sorry for the resistor, I only see the schematic, not the BOM.


2 years ago

awesome and so useful ... Thanks brother it worked