Profile: Circuit Systems (India) Limited specializes in providing printed circuit boards. We also offer capacitors, transistors, potentiometers, modules, relays, and resistors. We also offer PCB layout, PCB fabrication, component sourcing, and PCB assembly. Our USB battery charging circuit is a simple and a low cost lithium battery charging breakout board. It utilizes a micro USB for connecting the breakout board to any computer or USB wall adapter. It works with linear charging method. It offers 1000mA charge current by default but it is adjustable from 50mA to 1000mA by soldering a resistor.