Using an OTG cable while charging

Most Android devices have a single port for both connecting to the computer (USB) and charging. I have to use this OTG small cable to transfer data, but also to use a real keyboard. However, when I connect the keyboard, I cannot recharge my device while I work. Since they both use the same port, is there a way to split an OTG cable to introduce power on it, but keep the existing port so I can connect a keyboard ?