The Power Shield is the best way to—you guessed it—provide power to your mobile Particle projects. Based around the MCP73871 battery management controller, this shield allows you to simultaneously power a Photon and charge a connected Li-Ion or Li-Po battery. You'll also be able to monitor battery levels using the Photon itself, which makes the Power Shield the best way to untether your wireless project.
Besides the on-board USB port, you can also use an external DC power supply or solar-cell to charge the battery.
This shield ships with a 3.7V, 400mAh Li-Po battery and headers.
Designed for use with the Photon, backwards compatible with the Core.
Operating voltage: USB or External DC of 7 to 20V
Current consumption: 500mA max (USB) & 1.2A max (other DC sources)
Dimensions: 1"x 1.84"
Please check the datasheet here.