SparkFun LiPower Shield

Is there anything an Arduino cannot do? Well, for one, most of them cannot be powered directly by a 3.7V LiPo battery; much less monitor the charge of this battery. The LiPower Shield takes care of that by combining the functionality of two of our favorite batteries: the power cell and the fuel gauge.

The LiPower Shield allows you to connect a 3.7V single-cell lithium polymer battery, boosting it to 5V and connecting it to the 5V pin of the Arduino board. The onboard MAX17043G+U IC is connected to the I2C lines (A4 and A5), so your project has its own power supply. The configurable alarm interrupt pin on the MAX17043G+U IC is broken out to D3, which is activated when the LiPo reaches 32% or lower.

The charging circuit is configured to charge the LiPo at 100mA, but by adding a resistor to the provided through-holes, you can increase this to 500mA. There is a mini-USB port on the shield that allows you to charge the battery from a USB power source, or you can use a separate regulated 5V source at the "charge" pin.

Note: We decided to remove the operational indicator LED (LED1) and its current-limiting resistor (R3) from this board, as they pose a significant load on the battery. Please be aware that your board will have a few shiny, unpopulated pins.

Note: There is a known hardware issue that allows the LiPo to discharge below the point where the charging circuit can recharge it. However, thanks to the onboard fuel gauge, clever programming could prevent your project from draining the battery when it gets too weak.

We provide this shield with a free set of stackable headers!.