5A MPPT Solar Charge Controller 8-28V 100W Battery Charger Board MPPT-V08A

🔧 MPPT-V08A 5A Solar Charge Controller | AuscomTech

The MPPT-V08A is a compact, high-efficiency solar battery charging module featuring Maximum Power Point Tracking (MPPT), adjustable charging voltage and automatic CC/CV charging management.

Designed for solar panels operating within an 8–28V DC input range, this controller supports up to 5A charging current with an adjustable 5–26V output. It is suitable for compatible lithium-ion, LiFePO4 and lead-acid battery systems when correctly configured.

With dedicated MPPT and charging voltage adjustment, reverse-current protection, automatic daytime charging and an integrated heatsink, the board is ideal for DIY solar power systems, off-grid electronics, solar lighting and rechargeable battery projects.

⭐ Key Features

• True MPPT Charging Function – Adjustable maximum power point tracking helps improve energy harvesting by controlling the solar panel operating voltage.
• Up to 5A Output – High-current charging capability for compatible battery systems, subject to available input power and cooling.
• 100W Solar Panel Applications – Designed for small photovoltaic systems with panel power up to approximately 100W, within electrical limits.
• Adjustable Charging Voltage – Supports different battery configurations through an onboard voltage adjustment potentiometer.
• Automatic CC/CV Charging – Provides constant-current and constant-voltage regulation with trickle charging capability.
• Independent MPPT Adjustment – Dedicated potentiometer allows matching the operating point to the solar panel’s maximum power voltage.
• Automatic Solar Charging – Responds to available sunlight and adjusts charging current according to input power conditions.
• Low Standby Consumption – Approximately 3mA no-load current for low-power solar applications.
• Reverse Polarity Protection – MOSFET-based input protection helps reduce damage from incorrect connections.
• Reverse Current Blocking – Helps prevent the connected battery from discharging through the solar input overnight.
• Red and Blue Status LEDs – Visual indication of charging operation and charge completion.
• Soft-Start Operation – Supports controlled startup when solar input power becomes available.
• High-Frequency Switching – 300kHz switching design with onboard filtering components.
• Integrated Aluminium Heatsink – Assists thermal management during higher-current charging.
• Convenient Screw Terminals – Direct connections for solar panel input and battery charging output.

📊 Technical Specifications

• Model: MPPT-V08A
• Product Type: Solar battery charging controller module
• Input Voltage: DC 8–28V
• Output Voltage: DC 5–26V adjustable
• Maximum Output Current: 5A
• Solar Panel Power: 1–100W (subject to electrical limits)
• Conversion Efficiency: Up to 95% peak (manufacturer stated)
• Charging Control: Trickle / Constant Current / Constant Voltage
• Switching Frequency: 300kHz
• Minimum Voltage Differential: Approximately 1V between input and output
• No-Load Current: Approximately 3mA
• Load Regulation: ±1% (specified)
• Voltage Regulation: ±0.5% (specified)
• Operating Temperature: -40°C to +85°C (specified)
• Current Setting: External resistor configuration, with 2A / 5A settings referenced
• Adjustment Controls: 2 × onboard potentiometers
• Status Indicators: Red and blue LEDs
• Connection Type: 4-position screw terminal block
• PCB Dimensions: 58 × 37mm
• Overall Height: Approximately 25mm including heatsink
• Mounting Hole Diameter: 3mm
• Mounting Hole Spacing: 52 × 32mm
• Cooling: Aluminium heatsink

🔋 Battery Compatibility

The adjustable charging output allows the module to be configured for several rechargeable battery types, provided the required charging voltage and current fall within the controller’s operating limits.

• 6V Lead-Acid Batteries – Suitable when configured to the battery manufacturer’s charging requirements.
• 12V Lead-Acid Batteries – Supported with adequate solar input voltage and correct charge settings.
• Lithium-Ion Battery Packs – Suitable for compatible series configurations using the required BMS protection.
• LiFePO4 Battery Packs – Supports compatible lithium iron phosphate configurations with correctly selected charging voltage.

Battery chemistry, cell configuration, charging voltage and protection requirements must be verified before connection. Not all battery types are suitable for the same charging profile.

⚙️ MPPT & Charging Adjustment

Two onboard potentiometers provide independent control over solar power tracking and battery charging voltage.

• MPPT Adjustment: Sets the solar panel operating point to improve power extraction at the panel’s maximum power voltage (Vmp).
• Charging Adjustment: Sets the battery charging voltage and upper voltage regulation limit.
• Automatic Current Regulation: Adjusts charging current according to available input power and battery conditions, within the configured current limit.

The module uses a step-down DC-DC converter architecture. Input voltage must remain above the required battery charging voltage for correct operation.

🔌 Wiring Connections

• SOLAR+: Solar panel positive input
• SOLAR-: Solar panel negative input
• BAT+: Battery positive output
• BAT-: Battery negative output

Connect the solar panel and battery to their designated screw terminals. Always confirm terminal markings and polarity directly on the PCB before applying power.

🛠️ Initial Setup

1. Connect a suitable solar panel or current-limited DC bench supply to the input terminals without connecting the battery.
2. Adjust the MPPT potentiometer to suit the solar panel’s specified maximum power operating voltage.
3. Set the charging voltage using the onboard regulation potentiometer.
4. Measure the output with a multimeter and confirm the correct charging voltage for the battery chemistry and configuration.
5. Connect the compatible protected battery, verifying positive and negative polarity.
6. Monitor charging voltage, current and module temperature during initial operation.

Important: Always configure and verify the charging voltage before connecting a battery. Incorrect settings can cause overcharging and permanent battery damage.

🧩 Typical Applications

• DIY solar battery charging systems
• Small off-grid photovoltaic installations
• Solar-powered LED lighting projects
• Arduino and ESP32 renewable energy projects
• Remote sensor and telemetry power systems
• Portable solar battery charging equipment
• Low-power outdoor monitoring equipment
• Solar-powered data loggers
• Custom rechargeable battery power supplies
• Renewable energy prototyping and education

⚠️ Important Notes

• DC Power Only: Do not connect directly to AC mains electricity.
• Buck Converter Design: This module cannot boost voltage. Solar input must be approximately 1V or more above the intended charging output.
• Manual Configuration Required: The board does not automatically identify battery chemistry or select a charging voltage.
• Panel Voltage Limit: Solar panel open-circuit voltage (Voc), including under cold conditions, must remain within the 28V maximum input rating.
• Current and Power Limits: The 5A and 100W ratings are maximum operating figures, not guaranteed simultaneous output under all conditions.
• Lithium Battery Safety: An appropriate BMS is required. Never charge unprotected lithium battery packs.
• Charging Compatibility: Verify that the module’s CC/CV charging behaviour is appropriate for the intended battery. It does not replace specialised chargers requiring additional chemistry-specific charging stages.
• MPPT Setup: The maximum power operating point requires manual adjustment; the board is not a fully self-configuring solar regulator.
• Thermal Management: Provide ventilation around the heatsink when operating at higher charging currents.
• No Dedicated Load Control: This board does not include a separate load switching output or programmable low-voltage battery disconnect.
• Not Waterproof: Install in a suitable protective enclosure when used outdoors.
• Microcontroller Compatibility: Suitable for powering battery-based Arduino and ESP32 projects through appropriate regulation circuitry. No direct digital communication interface is provided.

📦 Package Includes

• 1 × MPPT-V08A 5A Solar Charge Controller Module with heatsink

🔗 Recommended Accessories (Not Included)

• Compatible Solar Panel – Provides renewable DC input power within the voltage and power specifications.
• Lithium Battery Management System (BMS) – Provides additional battery protection when charging lithium battery packs.
• Digital Multimeter – Used to verify output voltage, polarity and charging settings.
• DC Voltage / Current Meter – Enables monitoring of charging performance and battery current.