LiPo Battery Breakout for USB/WiFi Nugget

We've been testing our LiPo battery breakouts for the past year, and now, we are finally releasing our alpha prototypes, for anyone wanting to make their Nugget portable with LiPo power!

This board supports LiPo batteries with Adafruit-style JST-PH two-pin connectors. In case you use a battery with the wrong polarity connector, the board includes reverse polarity protection with a warning light indicator. You can also change polarity of the battery by moving two resistors on the board.

This addon will power your Nugget from a LiPo battery, while still keeping you able to power it from your laptop - and even charging the battery! Among other features, this board includes a voltage divider on the A0 (GPIO3 on the USB Nugget) pin for measuring battery voltage, as well as a switch for turning your device on and off. There's also a charging LED which shines purple as long as the charging process is happening, so that you can see when your battery is fully charged.

The addon works with both the WiFi Nugget and USB Nugget. Furthermore, it's also thin and narrow enough to work with any addons our team might develop in the future, fitting between any addon board and the Nugget! For instance, it should work well with the breadboard addon. 

There's two ways you can attach this board. You can solder a 8-pin header and plug the board into the Nugget. You can also insert a 8 pin header into the holes on the addon - they are staggered to make press-fit contact. This aspect also allows you to insert the battery addon between the Nugget and an addon board.


The battery add-on does not include a LiPo battery, but you can buy one from Adafruit or other places! Just make sure that the connector is two-pin, and if it isn't, it's not hard to rewire such a battery. See: https://hackaday.com/2022/10/03/lithium-ion-batteries-are-easy-to-find/

- It's only possible to power the Nugget off using the switch while USB power isn't applied - once you apply USB power, the Nugget will boot up either way.

This addon does not support LiFePO4 batteries. You should not use a LiFePO4 battery with this addon.

This addon only supports single-cell batteries with voltages marked as 3.6V/3.7V/3.8V or 4.1V/4.2V/4.3V. You should not use a LiIon pack with two cells in series or higher (voltage 7.2V or above).

If you decide use AA or AAA batteries instead (three in series), you should cut the jumper marked "LiIon" on the PCB, and check with the multimeter that it's properly cut. The purple (charging) LED should not light up during USB plug-in if the jumper has been successfully cut.

Any battery experimentation is solely at your own risk.

NOTE: ALPHA PROTOTYPES CONTAIN KNOWN BUG:

- May not charge from USB-C ports on some laptops when using a USB-C to USB-C cable (for instance, the Framework laptop). Workaround: turn the switch into OFF position, plug in laptop USB type c cable, then flip the switch back ON. Alternatively, use a USB-A to USB-C cable. We have a new revision in the works that solves this problem.

This prototype is being released in alpha stage, meaning there may be additional bugs that could damage your battery or microcontroller board. While our team has made a best effort attempt to identify any issues in testing for the past year, it is still possible that there are scenarios we have not considered. By purchasing this board, you acknowledge this risk and agree that any damages that may result are not the responsibility of our team.