SparkFun Sunny Buddy - MPPT Solar Charger

The SparkFun Sunny Buddy is a MPPT (Maximum Power Point Tracking) solar charger designed specifically for single-cell LiPo batteries. This solar charger is engineered to extract maximum power from your solar panel or any photovoltaic device and efficiently transfer it to a rechargeable LiPo battery. It's as simple as connecting your solar panel to one side and your battery to the other, and you're all set to start charging.

The Sunny Buddy is designed to charge a single polymer lithium-ion cell, with the load connected in parallel with the battery. It comes with a default maximum charge current of 450mA and a maximum recommended input of 20V (minimum 6V). It's advisable not to charge batteries more than their capacity rating, hence, the smallest battery that should be charged with the Sunny Buddy is 450mAh.

The Sunny Buddy comes equipped with an LT3652 power tracking 2A battery charging circuit. It also features pre-installed barrel jack and 2-pin JST connectors. There are unpopulated areas where you can install personal 3.5mm screw terminals for additional input/output options. This model also includes a potentiometer on the input to set the holding voltage for MPPT. The feedback resistors on the output have been tweaked to change the float voltage.

For further technical details, refer to the following documents:

Schematic, Eagle Files, Datasheet (LT3652), Hookup Guide, Weather Station Tutorial, GitHub (Design Files)

The SparkFun Sunny Buddy is not just a solar charger, it's a tool for efficient and sustainable energy usage. Whether you're powering a remote weather station, a drone, or any other device running on a single-cell LiPo battery, the Sunny Buddy ensures you get the most out of your solar panel. Its unique properties and easy setup make it an ideal choice for your energy needs.