Pimoroni Pico Lipo 2

Support
1

Using the Pico Lipo 2, to drive a LED display in an enclosure with battery backup, logic handled by the RP2350.
There seems to be a limitation with the Pico Lipo 2 in that if being powered from the battery, you cant seem to get it to start unless you press the onboard power button, and whilst this is ok for breadboarding, it’s an issue when the controller and battery are in an enclosure with USB power and data on a passthrough into the enclosure (which does allow charging and programming - but doesnt wake up the pico when off), and the button isnt accessible. Anyone got any ideas?

2

No, this is a known design error, already present on the first generation Pico Lipo. You have three options:

  • replace the Pico Lipo 2 with a “normal” Pico2 (Plus) and use the Lipo-Shim
  • use intelligent firmware that uses RP2350 PowMan low-power states. The new generation of Badger/Tufty don’t have any power-off button either, they all do it in software, i.e. they don’t turn off and keep running at a very low power state instead. This feature is currently not available in the normal PimoroniPython as far as I know, so you are on your own
  • Remove the power button and solder wires to the pads. Only do this if you are very good at soldering, since the pads are not really meant for that.
3

Another option if you’ve designed the enclosure yourself, and/or have access to a 3D printer is to fashion some kind of blunger that’s accessible from the outside of the enclosure that when pressed will press on the Pico Lipo’s button.

4

Good point. I use this Plasma 2040 case by Raspberry Pi | Download free STL model | Printables.com for my Plasma2040. I printed the stamps for the buttons in different colors and it works great.

5

This is a known behavior on many RP2040/RP2350 battery PMIC boards like the Pico Lipo 2 — the load switch is effectively “latched off” in battery mode, so USB presence alone doesn’t always wake the system unless the power-path IC is configured to auto-start.

If the board doesn’t support auto-boot on VBUS detection, you typically need either:
• A firmware-controlled power-hold (if the board exposes EN/PS pin)
• Or hardware modification so VBUS presence triggers the enable pin
• Alternatively, configure the PMIC (if supported) for “auto power-on when USB/battery present”

Without that, the physical power button is acting as the only wake trigger, which is exactly the limitation you’re hitting in enclosed setups.

6

thanks - I did consider the soldering option, and have managed to solder to one side of the power button, but think the other side might be too tight. Appreciate the information.

7

thanks - this could be a way forward, as I have designed and printed the existing enclosure. Wanted to explore and rule out any other options before I changed the external design.