SparkFun Sunny Buddy MPPT Solar Charger

This is the Sunny Buddy, an MPPT solar device (Maximum Power Point Tracking) charger for single-cell LiPo batteries. This MPPT solar charger allows you to transfer the maximum possible power from your solar panel or another photovoltaic device into a rechargeable LiPo battery. The setup is also straightforward: simply connect your solar panel to one side of the Sunny Buddy and your battery to the other, and you're ready to start charging!

The output of the Sunny Buddy is designed to charge a single polymer lithium-ion cell. The load should be connected in parallel with the battery. By default, the Sunny Buddy is set to a maximum charging current of 450 mA with a maximum recommended input voltage of 20 V (minimum 6 V). It is recommended that the batteries not be charged beyond their capacity rating; therefore, the smallest battery that should be charged with the Sunny Buddy is 450 mAh.

Each Sunny Buddy is equipped with an LT3652 power-tracking 2A battery charging circuit and features a pre-installed running socket as well as a 2-pin JST connector with unoccupied areas for installing your personal 3.5 mm screw terminals for additional input/output options.