This CN3791-based module is a compact MPPT (Maximum Power Point Tracking) solar charge controller designed to charge 1S (single-cell) 3.7 V lithium-ion batteries directly from 12 V solar panels. It maximizes energy harvest under varying sunlight conditions and includes onboard protection features for safe battery management.

Specifications

• Controller IC: CN3791 (MPPT lithium charger)
• Input Voltage: 6 V to 28 V DC (12 V solar panel recommended)
• Charging Voltage: 4.2 V (fixed for 1S Li-ion)
• Charging Current: Up to 2 A (depends on panel and load)
• Battery Type: 1S 3.7 V Li-ion / Li-polymer
• Charging Algorithm: CC/CV with MPPT tracking
• MPPT Efficiency: Up to 96% (typical)
• Protection Features:
  • Overvoltage
  • Overcurrent
  • Overtemperature
  • Reverse polarity
• Status Indicators:
  • Charging (red LED)
  • Fully charged (green LED)

Features

• MPPT algorithm optimizes solar energy harvest under dynamic lighting
• Designed for direct solar panel input (no external regulator needed)
• Compact footprint for portable and embedded solar charging applications
• Onboard LEDs for charge status indication
• Ideal for solar-powered IoT nodes, battery banks, and outdoor sensors
• Common use cases:
  • Charging 18650 cells from 12 V solar panels
  • Solar-powered weather stations and garden lights
  • Remote telemetry and low-power embedded system