SD05CRMA Solar Charging Module 4.4V 6.5V Input for 18650 LiPo Li ion Battery

SD05CRMA Solar Charging Module 4.4V 6.5V Input for 18650 LiPo Li ion Battery is a sophisticated, high-efficiency power management solution tailored for harvesting solar energy to charge single-cell lithium-based batteries. This compact module utilizes a specialized charging algorithm that ensures maximum power extraction from photovoltaic panels while maintaining the safety and longevity of your 18650 or Li-Po cells. Consequently, it serves as an ideal bridge between fluctuating solar outputs and sensitive battery chemistry. Furthermore, the integrated charge management controller handles the transition between constant-current and constant-voltage phases automatically. Therefore, you can deploy this module in remote environmental sensors or outdoor DIY projects with full confidence in its autonomous energy regulation capabilities.

Key Features:

• Optimized Solar Input: The module accepts a wide input voltage range from 4.4 V to 6.5 V, specifically matching the typical output profiles of small 5 V and 6 V solar panels.
• Automatic Charging Cycle: It manages the entire charging process, including pre-conditioning, constant current, and constant voltage modes to maximize battery health.
• Status Indicators: On-board LEDs provide immediate visual feedback regarding the charging state and completion status for easier debugging.
• Low Power Consumption: This device draws minimal current during standby, ensuring that your stored battery energy remains preserved for the actual application.
• Safety Protections: Integrated circuitry protects against battery overvoltage and provides automatic recharge cycles once the battery voltage drops below a specific threshold.

Technical Specifications:

• Input Voltage Range: DC 4.4 V to 6.5 V
• Output Charging Voltage: Fixed at 4.2 V ±1% (Standard for Li-ion/Li-Po)
• Maximum Charging Current: ≈ 1 A (Adjustable via external resistor if required)
• Operating Ambient Temperature: −40°C to +85°C
• Charge Status Indication: LED “CR” for charging and “OK” for full charge
• Quiescent Current: ≈ 100 μA in standby mode

Mechanical Specifications:

• Module Type: Non-isolated Buck/Linear Battery Charger
• PCB Material: High-quality FR-4 fiberglass with tinned solder pads
• Mounting: Solder-hole interface for secure wire or pin header attachment
• Durability: Solid-state design with high resistance to vibration and thermal cycling.

Dimensions:

• Board Length: ≈ 23.9 mm
• Board Width: ≈ 15.4 mm
• Maximum Height: ≈ 4.0 mm
• Weight: ≈ 5.0 g

Pinout and Wiring:

• Pin VIN: Connect the positive terminal of the solar panel or DC power source (4.4 V to 6.5 V).
• Pin GND: Common ground connection for both the input source and the battery.
• Pin BAT: Connect to the positive terminal of the 3.7 V / 4.2 V Lithium battery.
• Wiring Note: However, ensure you use sufficiently thick wires for the battery connection to prevent voltage drops that could prematurely trigger the termination phase.

Datasheet Reference:

• Download SD05CRMA Charge Controller IC Datasheet

Commonly Used in:

• Solar-Powered Lighting: Charging internal batteries for garden lights and emergency pathway markers.
• Remote Data Loggers: Powering wireless weather stations and soil moisture sensors in off-grid locations.
• Portable Power Banks: Adding solar charging capabilities to small DIY 18650-based backup power systems.

Applications:

• Renewable Energy Harvesting: Converting sunlight into chemical energy for continuous device operation throughout the night.
• IoT Edge Devices: Maintaining uptime for ESP8266 or LoRa nodes deployed in rural or inaccessible areas.
• Battery Maintenance: Providing a slow trickle charge to backup batteries stored in outdoor enclosures.

Equivalent Models:

• CN3065: A popular alternative solar charger IC with similar voltage constraints and integrated status pins.
• TP4056: Standard lithium charger, however, it lacks the optimized low-voltage start-up profile of the SD05CRMA for solar use.
• MCP73871: A Microchip alternative offering sophisticated load sharing, though it involves a more complex circuit implementation.

Package Includes:

• 1 x SD05CRMA Solar Charging Module 4.4V 6.5V Input for 18650 LiPo Li ion Battery