Switch power banks by temporarily attaching two of them

Question

I'm having a hard time finding out, if it's possible to have two power banks attached to a pi. Is there something like an Y-cable or something?

Use case is, that I'm planning on doing a timelapse video. I would power the pi with one power bank. When the power bank is almost empty, I would plug the second one on and take the first one with me to charge it again. I'm not looking for solutions with battery packs powering the pi over GPIO or something. Just clean and easy switch the power banks.

Thanks in advance.

Answer 1

I don't think a Y-cable would work since the two power banks would compete and eventually (if not instantly) one of them would break and possibly take the Pi with it.

This solution might work (it will work, I've done this):

1. Get a smaller capacity power bank that can handle the Pi for a few seconds/minutes (this will act as a buffer).
   • Make sure the small power bank can charge and provide power simultaneously.
   • Some power banks disable their output when they are charging. (e.g. Pineng)
2. Attach Pi to smaller power bank's output.

3. Attach main power bank to small power bank's input.

   Main power bank --> Buffer power bank --> Pi
   

In this setup, when you disconnect your main power bank, your small power bank will supply your Pi.

When a fresh power bank is attached, the small power bank charges itself until full while providing power to the Pi.