I currently have two external drives, a wd and seagate 4 and 6tb. I plan on getting another one as a backup. I'm not sure what i will be getting, if I can still get the same models as the ones I have or not. I wonder if it's ok to use the power supply for my existing drives on a new one even if it's a different model or brand? Are voltages the same for all these external drives or do i need to use the power cable supplied with the specific drive?