Have you considered creating a version of the LiPo expansion board with a MAX17048 chip to act as a Battery fuel monitor and also provide low voltage alerts to the Pico GPIO to deal with such conditions?
Alternatively, would you consider a PiicoDev board as a separate battery monitor?
This kind of module will be very useful to many projects…
The PicoDev range created by Core Electronics is excellent. Sensibly priced and very easy to use. I would welcome any additions to the range that serve a useful purpose.
The MAX17048 is an excellent chip for what it is designed to do; provide an indication of battery level to a micro device.
A recent project of mine involved a MakerVerse Nano Timer, Pico W and temperature sensor powered by a Lipo battery. The timer would wake the Pico every 15 minutes to read the temperature and transmit it via WiFi to another Pico W.
My problem was I did not want the Pico totally exhausting the power of the Lipo, which would be damaged as a result. I setup a voltage divider on one of the analog pins. The Pico reads this when powered up and if too low immediately switches off.
Ideally I would have liked the ability to disconnect the battery completely if the level fell too low.
Maybe this could be considered as an addition to the Lipo expansion board if a MAX17048 is to be added. But this may make the boards too expensive and complicated.
Anyway it is up to Core Electronics, just a suggestion.
Thank you James for your comments and sharing details about your project. I too considered a voltage divider but was concerned with the small but continuous drain on the battery.
I have also noticed that Adafruit and others have Max17048 modules that are reasonably priced and incorporating one on the LiPo Expansion board would be even more economic as it would require a fewer part count in terms of connectors, etc.
I do hope the guys at Core consider it, so that PiicoDev becomes a complete ecosystem with lots of possibilities.
The voltage divider current is not an issue.
The MakerVerse Nano timer removes power to the Pico when on a shutdown cycle.
The timer is a welcome addition to the Core Electronics range.
It was something I had been looking for to shutdown power and reduce current drain on a battery.
50nA or so when shutdown is awesome.
It does have some limitations.
The amount of power that can be switched is limited to about 100mA.
The timer runs all the time and drops power at the end of the cycle briefly so the Micro has to do all its stuff within the cycle or else it gets reset.
This sounds like it could be a great addition to the PiicoDev or Makerverse range.
I’ll let @Michael know there’s some interest here in case he has anything to add or there are other barriers to consider.
One of the biggest hurdles lately has been getting a solid supply of the chips required to make PiicoDev modules, so the availability of the MAX17048 or equivalent battery monitor ICs will probably be a large factor in how viable this module is and will take some time to investigate.
I understand that there are a lot of factors influencing what to develop next in PiicoDev range. I hope in this case that chip availability will not be an issue. My preference would be first for a LiPo expansion board version and second an independent PiicoDev module for these projects that do not want to use the LiPo expansion.
Does anyone know the name and specs of the battery connector on the PiicoDev LiPo Expansion board? Does @coreelectronics sell a fly lead with the connector and bare ends? I’ve asked support but they don’t seem to understand the question Thanks.
I did a search for PL 612338 LiPo on Google, came up with an Amazon item.
It looks like the wires are opposite to the LiPo’s sold by Core Electronics.
That would explain the smoke. The red and black wires are the wrong way around.
Without more information that is my best guess.
EDIT: Apparently there is no standard for the red / black wires and the JST connector.
It is a buyer beware situation. Always double check the polarity, something I will be more aware of now.