Charging batteries with Arduino Nano

Hi, I am pretty new to arduino and I would like to ask for your help.

I am currently trying to power my Arduino nano with rechargable batteries. I used 6 2/3 NiMH batteries in series to get 7.2 Voltage and connecting it to the VIN Pin.

Now I am trying to get those batteries to be rechargable as well. What would the best way to do that? Is it possible to just charge the batteries over the arduino by connecting a source to the mini-usb jack?

I attached a picture of what it looks like.

Thank you in advance.

Greetings, Tobias

Picture?

You need to charge the battery at its terminals, you can’t put power backwards through the on-board
regulator.