Hi! I am new here and new to circuit building (I do electronics but havent done much component level and it's been a while since I graduated tech school. So, I have a 6V 1.5W solar panel. I also have a DC to USB board I pulled from a car charger. What I would like to do it connect a battery between the solar panel and usb charger so that I could use it to charge the phone etc in cases of night-time charging or cloudy days (I camp a lot and plan on using it then). Any ideas how I can regulate the circuit to put out between 200-500 mA and 5V? Thanks!