Sunny Buddy - MPPT Solar Charger (SparkFun USA)

Sunny Buddy is a maximum power point tracking (MPPT) solar charger for single-cell LiPo batteries. This MPPT solar charger provide you with the ability to get the most possible power out of your solar panel or other photovoltaic device and into a rechargable LiPo battery. Set-up is easy as well, just plug your solar panel into one side of the Sunny Buddy and your battery into the other and you are good to start charging.

The output of the Sunny Buddy is intended to charge a single polymer lithium ion cell. The load should be connected in parallel with the battery. By default, the Sunny Buddy comes set to a maximum charge current of 450mA with a maximum recommended input of 20V (minimum 6V). It’s recommended that batteries not be charged at greater than their capacity rating; thus, the smallest battery that should be charged with the Sunny Buddy is 450mAh.

Each Sunny Buddy comes equipped with a LT3652 power tracking 2A battery charging circuit and pre-installed barrel jack and 2-pin JST connectors with unpopulated areas to install your own personal 3.5mm screw terminals for added input/output options. This revision also adds a potentiometer to the input to set the holding voltage for MPPT and we’ve also tweeked the feedback resistors on the output to change the float voltage.

Features of Sunny Buddy - MPPT Solar Charger
 

• Solar charger for single-cell LiPo batteries
• Onboard barrel jack footprint
• Onboard battery charger
• Provision for secondary barrel jack footprint.
• Onboard LT3652 is a battery charger that operates over a 4.95V to 32V input voltage range.

Specifications of Sunny Buddy - MPPT Solar Charger
 

• The maximum recommended input to the board is 20V
• The minimum recommended input to the board is 6V
• Load can be connected to either the 0.1" or 3.5mm
• The smallest battery that should be charged with the Sunny Buddy is 450mAh.
• Maximum charge current of 450mA with a maximum recommended input of 20V
• 2A battery charging circuit

Package includes:
 

• 1 x SparkFun Sunny Buddy - MPPT Solar Charger

Development resources:
 

• Schematic
• Eagle Files
• Hookup Guide
• GitHub (Design Files)