i have a battery pack 4 aa, a led with built in resister, on off switch 3 pin and a power step up module, what i need is simple instructions on how to put it all together so that i can have an portable usb charger with an on/off switch and a led on indicator if anyone can help me please do. btw i have some solar panels that i can use to charge them if i can do it so that it will not over charge the batteries and mess them up the panels in full light gets 5v in low light about 3 if that helps thanks to any one that can help me