Its totally safe and you may alter the design too. I didn't have design to any 3d printing source ,so that's why my design has everything with scratches and stuff (my hands are unsteady). One more thing, doesn't matter what shape you give to your charger , but try to place the components like i did, they turn out handy in that way. This design has my copyrights! © :D good luck
Step 1: Stuff Required
2. A 3.5~3.8 volt battery (you can use a 5v battery too but you will have to use a suitable resistor.
3. 3 bright l.e.d s and a small green led .
4. 2 X 200ohm resistors.
5. An ON/OFF switch and a bypass switch ( i have showed how to make one in the circuit diagram)
6. Wires, soldering iron.
7. Quick/super glue. (don't use a glue gun)
8.Scissors , tweezers etc.. for precision cutting.
Step 2: Positioning, Soldering, Gluing...blah Blah Blah.
2. Now make small cavities on the top side of the box for placing the two outlets, don.t place the usb port facing upward as it can dislocate from its position while removing a usb cable.
For placing the usb port, you will have to make a rectangular cavity on the side of the box, be sure its on the same side where the other two outlets are.You can provide the outlets support by placing glued bits of cardboard side to side with them and gluing them together.
3.Now place the two switches like i place them, and use cardboard bits if necessary.
For making the bypass switch , find a switch which has 5 connectors and connect the power- in wire to the middle one.Connect a 200 ohm resistor to one of the extremities, and a wire to the another, then join the free end of resistor to that wire on the other side. Cut out the remaining connectors and solder everything on the switch.
4.This circuit works in a parallel combination so you will have to connect the +ve terminal of each outlet to one red wire and the -ve one to a black one, solder it out, and for the lamp , connect the +ve wire going out from the lamp to that resistor and solder it. Also connect the "power in " wire to the +ve wire of the outlets, and connect the -ve wire of the outlets to the -ve terminal of the led circuit.
(oh yeah, for the indicator light, connect a resistor to one of the end of the green led and join its +ve and -ve terminals to the wire hub we have created so far.)
Finally place the main ON/OFF switch to side and join one of the wires of the hub with it, connect the other wire of the hub with the battery directly, finally join the other free end of the switch to the battery and solder everything up............phew! we're done for now.
Step 3: The Result.
Feel free to place any doubts, queries ....I'm happy to help.
Thanks for viewing
And sorry if my English sucks.