SparkFun LiPo Charger Plus

The SparkFun LiPo Charger Plus is a high-powered single-cell lithium polymer (LiPo) battery charger. This model features a USB-C input charge connector along with an option for charge rate selection and thermal protection. The board is compatible with any 2-pin JST connector single cell LiPo batteries in the SparkFun range. Charging progress is indicated by charge, power, and done LEDs.The MCP73833, which operates at an input voltage between 3.75V-6V, can charge at a maximum rate of 1000mAh. It offers two types of thermal protection. An internal sensor ensures the maximum charging rate until the die temperature of the IC reaches approximately 95°C. The charge controller then reduces the charge rate to prevent overheating. The MCP73833 also comes with an optional input pin for an NTC (negative-temperature coefficient) thermistor, providing an additional layer of protection against possible battery damage.The SparkFun LiPo Charger Plus has a host of features that make it a reliable and efficient battery charging solution. It is a complete linear charge management controller with an integrated pass transistor, current sense, and reverse discharge protection. It operates on constant current/constant voltage with thermal regulation. The charge current is programmable up to a maximum of 1A. The preset voltage regulation is highly accurate at 4.2V + 0.75%. The charger also has the ability to precondition deeply depleted cells with selectable current ratio and voltage threshold. It includes a cell temperature monitor and a low-dropout linear regulator mode. The supply voltage ranges from 3.75V-6V.For users who are interested in understanding the inner workings of the SparkFun LiPo Charger Plus, a schematic, eagle files, a hookup guide, a Fritzing part, a datasheet for the MCP73833, and a GitHub hardware repo are available.