There are two ways to power your Feather:

1) Power with a USB Cable connected to a power source.

2) Connect a 4.2/3.7V Lithium Polymer (LiPo/LiPoly) or Lithium Ion (LiIon) battery to the JST jack. This lets you run the Feather without wires, untethered.

If you're running off of a battery, chances are you want to know what the voltage is. That way you can tell when the battery needs recharging. 

In this section, you'll connect a battery to your Feather, and configure a battery monitor component from Adafruit IO to report the board's battery voltage and charge percentage. 

Where is the Battery Monitor on my Feather?

The Feather's  MAX17048 Battery Monitor is located directly above the STEMMA port, highlighted in pink.

Powering the Feather with a Battery

Adafruit highly advises using Adafruit batteries. They have the correct wiring and built in short circuit protection. Batteries from other sources may have incorrect wiring and/or no short protection.

You can plug any 250mAh or larger 3.7/4.2V Lipoly battery into the JST 2-PH port (identified in the diagram below) to power your Feather and charge the battery. The battery will charge from the USB power when USB is plugged in. If the battery is plugged in and USB is plugged in, the Feather will power itself from USB and charge the battery up.

For more information about powering your Feather, visit the Power Management Page in this guide.

Add Battery Monitor Component to Adafruit IO

From your device page, click the New Component (or +) button.

Search for the component name by entering MAX17048 into the text box on the component picker, the list of components should update as soon as you stop typing.

Filtering and searching for components

Since WipperSnapper supports such a large number of components, there is keyword filtering. Try searching for various keywords, like:

  • component names: aht20servobuzzerbutton, max17048, etc
  • sensor types: lighttemperaturepressurehumidity, etc
  • interface: i2cuartds18x20pin, etc (also I2C addresses e.g. 0x44)
  • vendor: AdafruitASAIRInfineonBosch, Honeywell, Sensirion, etc

There are added product and documentation links for every component, follow the links beneath the component descriptions to be taken to the appropriate product page or Learn Guide.

Select the MAX17048 from the list of results to go to the component configuration page.

There will be a back button if you select the wrong component, and you can use the Edit component icon (⚙️) on the device page to update the component configuration in the future.

The Create Component form should load, used for component configuration, with the MAX17048's I2C sensor address listed along with the sensor's settings.

On the Create MAX17048 Component form, there are two options:

  1. Enable the battery cell voltage reading. This will cause the Feather to report the status of its battery expressed in Volts.
  2. Enable the battery cell percent reading. This will cause the Feather to report the status of its battery expressed as a percent. 

Then, the battery measurement will be read and sent to Adafruit IO every "Send Every" period.

In the screenshot below, the battery monitor is configured to report its battery cell voltage and battery cell percentage back to Adafruit IO every 30 seconds.

After configuring the MAX17048 component, click Create Component.

Every 30 seconds, the Feather uses the MAX17048 component to measure its battery cell percent and voltage, and report it back to Adafruit IO.

Going Further

Now that you have a battery monitor component set up on Adafruit IO, you may follow this guide to configure an Adafruit IO Action for receiving an SMS text message when your Feather's battery level is below a threshold.

This guide was first published on Apr 20, 2022. It was last updated on Jul 18, 2024.

This page (Battery Monitor (MAX17048)) was last updated on Mar 26, 2024.

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