I understand that the Zero W USB port has just the power lines connected to all the power on the board (+5V and GND). I also understand that you can use something like Adafruit PowerBoost 1000C to power by connecting to those rails (e.g. using PP1 for +5V and PP6 for GND).
In that case, the PowerBoost would have a lipo battery, and you'd plug your power cable into its USB port (not the Zero W's USB port), and power would be intelligently distributed between the battery and the Pi.
The problem with that approach is instead of using the Pi's USB power port, I have to use the PowerBoost's power USB port. My desire is, because the Pi has all its jacks secure in a row, I'd like to use them as is.
My thought is:
- CUT the connection between the Pi's USB power port and its power rails.
- INSTEAD re-route the Pi's USB power port to input to the PowerBoost.
- Connect the PowerBoost output to the Pi's PP1/PP6 (fairly typical).
My question is whether this is possible and the best way to go about it.
I think in the worst case, the USB power jack could be removed from the Pi and reconnected so it's not touching the solder pads, then +5V wired from it to the PowerBoost. Would it be a problem if the GND is shared though?
Or, are there some traces I can cut to remove the Pi's power from USB power jack, without desoldering the USB power jack? Is there anywhere I can get a board layout of the traces to see where they go?
Finally, has anyone done something like this before? I know it's easier to just use the PowerBoost separately, but I'd really like to re-use the Pi's power jack if at all possible, as it's a cleaner solution if it can be achieved.