GitHub - sparkfun/Photon_Battery_Shield: Battery Shield for the Spark Photon. Has a charging circuit, as well as a fuel gauge.
![SparkFun Sunny Buddy - MPPT Solar Charger (MPPT) Solar Charger for Single-Cell LiPo Batteries LT3652 Power Tracking 2A Battery Charging Circuit: Amazon.com: Industrial & Scientific SparkFun Sunny Buddy - MPPT Solar Charger (MPPT) Solar Charger for Single-Cell LiPo Batteries LT3652 Power Tracking 2A Battery Charging Circuit: Amazon.com: Industrial & Scientific](https://m.media-amazon.com/images/I/81JfGXMtPeL.jpg)
SparkFun Sunny Buddy - MPPT Solar Charger (MPPT) Solar Charger for Single-Cell LiPo Batteries LT3652 Power Tracking 2A Battery Charging Circuit: Amazon.com: Industrial & Scientific
![Amazon.com: SparkFun LiPo Fuel Gauge System for Single-Cell Lithium-ion Batteries, I2C Interface, Voltage Range Between 2.5V to 4.5V : Toys & Games Amazon.com: SparkFun LiPo Fuel Gauge System for Single-Cell Lithium-ion Batteries, I2C Interface, Voltage Range Between 2.5V to 4.5V : Toys & Games](https://m.media-amazon.com/images/I/41-cinyngeL.jpg)