gkeyboard / mppt-2420-lc

Hackable and open source MPPT solar charge controller

MPPT Charger 20A

Outdated design, development of new revision ongoing.

Important: As we are currently developing a new revision of this charge controller with several improvements, it is not recommended to rebuild this device anymore. Please see this forum thread and feel free to contribute your ideas.

Features:

• 20A MPPT charger (buck converter)
• 55V max PV input
• 12V or 24V battery output
• 32bit ARM MCU (STM32F072)
• CAN communication interface with CANopen standard RJ45 jacks (including 10V power supply)
• Expandable via Olimex Universal Extension Connector (UEXT) featuring I2C, Serial and SPI interface (e.g. used for display, WIFI communication, etc.)
• Compatible to Hammond Mfg 1591XXCFL housing
• 5V switchable signal output
• USB connector for programming etc.
• Can be used as boost converter with software change
• Suitable for Li-Ion batteries with BMS (even recharge after low voltage disconnect possible, as the charge controller increases the voltage automatically when enoug sunlight is available)

Built-in protection:

• Overvoltage
• Undervoltage
• Overcurrent
• PV short circuit
• PV reverse polarity (for max. module open circuit voltage of around 40V)
• Battery reverse polarity (destructive, fuse is blown)