SanmeiLi DC 6-40V Battery Charger Discharger Control Switch User Manual

1. Introduction

This manual provides detailed instructions for the installation, operation, and maintenance of the SanmeiLi DC 6-40V Battery Charger Discharger Control Switch. This device is designed to protect batteries from undervoltage and overvoltage conditions during charging and discharging cycles, automatically disconnecting the load or charger when set thresholds are met.

2. Safety Information

• Always ensure the power supply is disconnected before making any wiring connections to prevent electric shock or damage to the device.
• Verify that the input voltage (DC 6-40V) is within the specified range to avoid damaging the control board.
• Observe correct polarity when connecting the battery and power supply. Incorrect polarity can cause irreversible damage.
• Do not exceed the maximum current rating of the relay (10A for 250VAC/30VDC) to prevent overheating and failure.
• Keep the device away from moisture, dust, and extreme temperatures.
• This device is intended for use by individuals familiar with basic electronics and electrical safety procedures.

3. Product Overview

The SanmeiLi DC 6-40V Battery Charger Discharger Control Switch features a compact design with a digital display, control buttons, and screw terminals for easy connection. It integrates a relay for switching power to the charger or load.

Figure 1: Angled view of the SanmeiLi DC 6-40V Battery Control Switch, showing the digital display, buttons, relay, and terminal blocks.

Figure 2: Top-down view of the control board, highlighting the digital display, 'STOP', 'SET', 'UP', 'DOWN' buttons, and connection terminals (VIN, GND, V+, V-).

Key Components:

• Digital Display: Shows current voltage and parameter settings.
• Control Buttons: 'STOP', 'SET', 'UP', 'DOWN' for navigation and parameter adjustment.
• Relay: Electromechanical switch for controlling external circuits (charger/load).
• Terminal Blocks: Screw terminals for power input (VIN, GND) and battery/load connection (V+, V-, NO, NC, COM).

4. Specifications

Figure 3: Dimensions (64.0mm x 40.0mm) and weight (28.60g) of the control board.

5. Setup and Installation

5.1 Wiring Connections

Refer to the labels on the terminal blocks for correct wiring. Ensure all connections are secure to prevent intermittent operation or damage.

• VIN / GND: These terminals are for the DC power input to the control board itself. Connect your 6-40V DC power supply here.
• V+ / V-: These terminals are for connecting the battery whose voltage you wish to monitor and control. Connect the positive terminal of the battery to V+ and the negative terminal to V-.
• NO / NC / COM: These are the relay output terminals.
• COM (Common): Connect the common line of your charger or load here.
• NO (Normally Open): The circuit between COM and NO is open when the relay is de-energized and closed when energized. Use this for charging control (charger connected when voltage is low) or load disconnection (load disconnected when voltage is low).
• NC (Normally Closed): The circuit between COM and NC is closed when the relay is de-energized and open when energized. Use this for discharging control (load connected when voltage is high) or charger disconnection (charger disconnected when voltage is high).

Note: The relay acts as a switch. You must wire your charger or load through the relay contacts (COM and NO/NC) to enable automatic control.

5.2 Mounting

The board can be mounted using appropriate standoffs or enclosures. Ensure adequate ventilation to prevent overheating, especially if the relay is switching high currents.

6. Operating Instructions

6.1 Power On

After connecting the power supply (VIN/GND) and battery (V+/V-), the digital display will show the current battery voltage.

6.2 Button Functions

• SET Button: Enters parameter setting mode. Press repeatedly to cycle through parameters.
• UP Button: Increases the value of the currently selected parameter.
• DOWN Button: Decreases the value of the currently selected parameter.
• STOP Button: In normal operation, briefly press to toggle the relay state (manual override). In setting mode, it can be used to exit without saving changes or to confirm.

6.3 Parameter Setting

Press the SET button to enter parameter setting mode. The display will show a parameter code (e.g., 'LVP', 'OVP'). Use UP and DOWN to adjust the value. Press SET again to move to the next parameter. After setting all parameters, press STOP to save and exit, or wait for a few seconds for automatic exit.

Common Parameters:

• LVP (Low Voltage Protection): Sets the minimum voltage threshold. If the battery voltage drops below this value, the relay will activate (or deactivate, depending on mode) to protect the battery from over-discharge.
• OVP (Over Voltage Protection): Sets the maximum voltage threshold. If the battery voltage rises above this value, the relay will activate (or deactivate) to protect the battery from over-charge.
• OP (Operating Mode): This parameter defines whether the device operates in charging control mode or discharging control mode.
• 'C' (Charge Mode): When battery voltage is below LVP, the relay closes (e.g., connects charger). When voltage reaches OVP, the relay opens (e.g., disconnects charger).
• 'D' (Discharge Mode): When battery voltage is above OVP, the relay closes (e.g., connects load). When voltage drops to LVP, the relay opens (e.g., disconnects load).

6.4 Auto Cut-Off Functionality

Once LVP, OVP, and OP parameters are set, the device will automatically monitor the battery voltage. When the voltage crosses the set thresholds, the relay will switch its state according to the selected operating mode, providing automatic protection for your battery.

7. Maintenance

• Keep the device clean and free from dust. Use a soft, dry cloth for cleaning.
• Regularly check wiring connections for tightness and signs of corrosion.
• Ensure the operating environment is within specified temperature and humidity ranges.
• Avoid exposing the device to strong vibrations or mechanical shock.

8. Troubleshooting

8.1 Display Not Lighting Up

• Check if the power supply (VIN/GND) is connected correctly and providing 6-40V DC.
• Verify power supply polarity.
• Inspect for any loose connections or damaged wires.

8.2 Relay Not Switching

• Ensure the battery is connected to V+/V- and its voltage is being displayed correctly.
• Check the LVP, OVP, and OP settings. The current battery voltage must cross the set thresholds for the relay to switch.
• Verify the operating mode (OP) is set correctly for your application (Charge 'C' or Discharge 'D').
• Test the relay manually by briefly pressing the STOP button. If it switches, the issue is likely with parameter settings.

8.3 Incorrect Voltage Reading

• Ensure the V+/V- connections to the battery are secure and free from corrosion.
• Compare the displayed voltage with a multimeter reading to confirm accuracy. If there's a significant discrepancy, the unit might be faulty or require calibration (if supported, refer to advanced settings not covered in this basic manual).

9. Warranty and Support

For warranty information, technical support, or service inquiries, please contact your retailer or the manufacturer, SanmeiLi, directly. Retain your proof of purchase for warranty claims.