Disclaimer: This Project can be done by any Amateur Electronic Hobbyist!
Every time I start packing my luggage for a Road-Trip, I always forget to pre charge my PowerBank. Then I regret not charging it. Sometimes, I totally forget including it as a part of my luggage. A PowerBank is a must carry gadget for any trip. But sometimes, when we intend to completely camp outdoors, we will not be able to find any power source to recharge our PowerBanks after it's battery has been completely drained. In such trips, there is no use of a PowerBank.
In order to solve the above problem, I have published this Instructable. In this Instructable, I will be teaching you how to make a 2$ travel charger within 30 minutes.
One important thing that we have to realise is that, all our bikes contain a huge 12volts battery enclosed within itself that auto recharges itself as and when we drive. So if we can exploit this valuable feature of our bikes, then we can always ignore taking our Powerbanks to all of our road-trips in future. Moreover, moteorbikes have a huge 12V battery with a capacity of 7Ah. This is equivalent to 2 to 3 10000mAh PowerBanks.
This method is intended to charge your phones only when you go on a road trip on your motorbikes. If you want to charge your phones while cycling or while you are inside a train, you can refer my previous instructable The Portable Wind Generator. If you are going on road trip via a car, then you can charge your phones using the car's inbuilt cigarette charger.
Step 1: Materials Required and Bill of Materials
Perforated Board Rs.10
7805 5V Voltage Regulators 2nos Rs.20
1uF and 470uF electrolytic Capacitors 2nos Rs.10
Female USB ports 2nos Rs.30
DC Jack Male Rs.10
DC Jack Female Rs.10
Single Strand Wires Rs.25
Plastic Casing or 3D printed Casing(Optional) Rs.15
Total cost incurred = Rs 120 ~= $2
I bought all the materials from a local electronics shop. You can buy them online too in which case the rates may slightly differ.
Step 2: Electronic Circuit
In the above circuit, I have used two sets of USB chargers. There is one common input power supply for both the sets of chargers. The tip of the DC power jack is the positive terminal. The sleeve must be connected to the negative terminal. Then connect the positive terminal to the positive terminals of the 470uF capacitors and the 7805 voltage regulators. The negative terminal of the power jack must be connected to the middle terminal of the voltage regulator. Couple capacitors of 1uF across the output terminals of the voltage regulator. The output of the voltage regulators must be connected to the input terminals of the female USB ports. Also solder two wires to a DC Male jack to it's respective male and female terminals. Finally, cut the perforated board to your desired size.
Refer the above figures in case of confusion. Personally request me in case you need PCB files for etching the above circuit. I have them ready.
Step 3: Installation and Working
If you don't want the charger to look geeky or if you want to protect it, you can enclose the whole circuitry inside a plastic casing that can be readily bought like what I did or design the casing and get it 3D printed. This is optional.
The above images shows the detailed connection of the overall circuit. Be sure to connect the positive and the negative terminals of the battery to the circuitry correctly.
Also, the placing and the method of opening battery compartments of different motorbikes vary. In such situations, learn how to open your bike's battery compartment by watching some youtube videos.
Step 4: Conclusion
I hope you clearly understood how to make a portable travel charger that can substitute your PowerBanks during all your road trips on a motor bike.
Feel free to ask any doubt that may arise during the process of your making. Also, don't forget to follow me for more such awesome instructables in future!