I intend to use the Arduino Pro Mini plate Atmega328p 5v 16 MHz, with a USB converter, because the final product will be as a USB pendrive would serve to communicate with software that I developed that changes the value of the vectors in C code, I will use a 9v battery to make the circuit, first thought about reloading the device with a photoelectric sensor But how the device will probably be kept in my Pocket I ruled out this option. Then I thought, it would be possible to use the USB to recharge the 9v battery? If so could you give me a help with related materials? If you don't like I would for the arduino recharge the battery?
Please help me with material about how to recharge the battery, I'm days researching this and I found a solution.
I'm not sure there is such an animal. USB is 5VDC and usually no more than 1.5A max. To charge a 9VDC battery. you would have to double the USB's output and then the power available would probably take a week to charge a 9V battery.
There are tons of mini USB chargers on ebay for 1S lithium batteries but those are only 3.7 volts. Change your battery voltage requirements to for one lithium and you should have no problem getting it charged with a USB port.