The use of solar power as a non-conventional energy source has become a very common thing now-a-days. Based on the extent of sun-exposure, solar cells or panels are being widely used to charge up D.C. batteries and cells attached to different electronic and electrical devices and gadgets. In this project, we shall build a travel charger (12 volts capacity) powered by solar energy in a briefcase housing. It makes use of a few simple electronic and electrical components. This set-up can be a great handy to charge your cellphone or laptop in a campsite, picnic or any outdoor party. Following are the steps to build a solar energy generating briefcase.
Moderately challenging (May require expertise in few areas)
The maximum estimated time required for this project is 2 days. It actually depends on the efficiency of the person involved.
- A briefcase with strong outer body and heavy metal hinges
- A 12 volt solar charge regulator
- Solar panel or a group of solar cells
- A 12 volt battery
- A wooden block (L-300mm X B-150mm X H-40mm)
- A piece of cloth or linen (to cover the wood)
- A multiple socket car charger
- Zip Tie
- PVC insulation tape
- Nut Bolts with double flat washers
- Flexible copper wire
- Wire stripper
- Hand drill machine
- Hand saw
The overall cost involved in this project is about $100.
- First of all, let us mount the solar panel on the upper surface of the briefcase. For this, take proper measurements of the screw holes (make 4 markings) already provided in the solar panel for mounting. Then, drill in four holes in the marked places. After making holes, mount the solar panel on the top of the briefcase with the help of the nut bolts and flat washers.
- Make another hole near the hinge for cable entry from the solar panel to the inner part of the briefcase. Make sure that this hole is made such that opening and closing of the briefcase doesn’t pinch or cut the incoming power cable.
- Next, prepare the mounting for the battery, car charger and the solar charge regulator. Take the measurements properly and saw the wooden block accordingly to make the mounting slots.
- Wrap the wooden block with the help of the cloth or linen and make it permanent with the help of the glue. This will save the components from vibration and scratches at the same time. Finally drill appropriate holes and screw down this block permanently to the base of your briefcase.
- Place the battery, the car charger and the regulator in the appropriate slots and tie them to the wooden mounting with the help of zip ties.
- Now it’s turn to start wiring these components. First of all, connect the two wires from the solar panel to the voltage regulator. Then, connect two wires from the outgoing point of the regulator to the battery terminals. Finally, connect the multiple car charger with the battery leads. You can also use low rated fuses in the circuit in series for over current protection purpose.
- You can connect any cellphone charger or laptop charger in the multiple charger socket to test if the circuit is working.
- Take your briefcase out in the sun. The glowing indicator LED in the multiple car charger will show that the circuit is OK and working. If you connect a cellphone to its charger inserted in the multiple charger socket, the mobile beeps up immediately indicating that it is getting charged up.
Frequently asked questions:
1. Is this project eco-friendly?
This project makes use of solar panels to extract the solar radiation and converts it to electrical energy to charge up the DC battery. Thus, the entire process is free from any type of pollutants and is completely eco friendly.
2. Is it portable?
This device is completely portable and light weighted. You can easily carry it to camp sites or outdoor parties and charge your cellphone or laptop using the sunlight.
- Make sure that the ratings of the solar charge regulator and the battery are same. Otherwise, your battery will never get charged.
- Look out for cloudy weathers. This device only works properly when fully exposed in the sunlight.
- The wire connections should be tight and insulated properly with the help of the PVC insulation tape to avoid any short circuits.
Things to watch out for:
- Never use a damaged or dead battery. Or else the battery may explode when subject to charging causing serious accidents.
- Strap the components tightly to the base of the briefcase to avoid any vibration or component damage.
- Never rely entirely on solar power as it is completely dependent on weather conditions. Always carry spare batteries with you outdoors.