My Macbook Won't Read External Hard-Drive But Can Be Read On Others.

Hello. Last night I plugged in a ac powered multi-usb into my usb input, I then received an error message which was something along the lines of ''too much power is being drawn,'' so I disconnected it and didn't think anything of it. This morning I plugged in one of my external hard-drives and my Mac didn't read it, so I tried another hard-drive but to no avail. I tried plugging those hard-drives into a friends Macbook and they worked. I then tired charging my iPod and my Mac and that worked. It seems as if there isn't enough power to pwer my external hard-drives?

Thanks for reading.