My current means of powering things is USB rechargable batteries. I have a about five of them that range between small 3000-5000mah ones to a big 20000mah interstate battery jump starter pack. Is there a device that lets me add all their power together into a centeral power source so I don’t have to keep swapping them out?
No…please do not do this.
The voltages of the output ports are probably not all exactly the same and you could end up damaging the device (or worse, starting a fire). They MIGHT have reverse current protection on them, but I’ve seen some pretty sketchy power banks.
You can’t just wire them in parallel. USB has communication pins that help boost circuits in the battery change voltages levels. Even if it all works, you’re going to get extremely poor charge times.
I don’t believe it’s out of the realm of EE to design something that allows you to plug in multiple power banks though, but I’ve never seen any