How to Use 3x Slot Battery Holder 18650 (Seri): Examples, Pinouts, and Specs

The 3x Slot Battery Holder 18650 (Seri) is a compact and durable component designed to securely hold three 18650 lithium-ion batteries in series. This configuration allows the holder to combine the voltage of all three batteries, making it ideal for powering high-voltage electronic circuits. The holder is equipped with sturdy terminals for reliable electrical connections and is commonly used in DIY electronics, robotics, portable devices, and renewable energy projects.

• Power supply for portable electronic devices
• DIY robotics and automation projects
• Renewable energy systems (e.g., solar-powered devices)
• High-power LED lighting systems
• Backup power supplies and battery packs

• Battery Type Supported: 18650 lithium-ion batteries
• Configuration: Series (voltage of all three batteries is added)
• Output Voltage: 3.7V × 3 = 11.1V (nominal, depending on battery charge)
• Maximum Current: Depends on the discharge rating of the batteries used
• Material: ABS plastic (holder body), nickel-plated steel (terminals)
• Dimensions: Approximately 80mm × 60mm × 20mm
• Weight: ~30g (without batteries)
• Wire Leads: Pre-soldered, typically 22 AWG

The 3x Slot Battery Holder has two main terminals for electrical connections:

1. Insert Batteries: Place three 18650 lithium-ion batteries into the holder, ensuring correct polarity. The positive and negative ends of each battery should align with the markings on the holder.
2. Connect to Circuit: Use the pre-soldered wire leads to connect the holder to your circuit. The red wire is the positive terminal, and the black wire is the negative terminal.
3. Secure Connections: Ensure all connections are tight and insulated to prevent short circuits.
4. Power Your Circuit: Once connected, the holder will provide a combined voltage of approximately 11.1V (nominal) to your circuit.

• Battery Selection: Use only high-quality, protected 18650 batteries to ensure safety and performance.
• Voltage Monitoring: Monitor the voltage of the batteries to avoid over-discharge, which can damage lithium-ion cells.
• Heat Management: Avoid exposing the holder to excessive heat, as it may deform the plastic or damage the batteries.
• Polarity Check: Double-check the polarity of the batteries and connections to prevent damage to your circuit.
• Fuse Protection: Consider adding a fuse to the circuit for additional safety.

The 3x Slot Battery Holder can be used to power an Arduino UNO via its VIN pin. Below is an example circuit and code:

• Connect the red wire (positive terminal) of the battery holder to the VIN pin of the Arduino UNO.
• Connect the black wire (negative terminal) of the battery holder to the GND pin of the Arduino UNO.

// Example code to blink an LED using an Arduino UNO powered by the 3x Slot Battery Holder
// Ensure the battery voltage is within the Arduino's acceptable range (7-12V).

const int ledPin = 13; // Built-in LED pin on Arduino UNO

void setup() {
  pinMode(ledPin, OUTPUT); // Set the LED pin as an output
}

void loop() {
  digitalWrite(ledPin, HIGH); // Turn the LED on
  delay(1000);                // Wait for 1 second
  digitalWrite(ledPin, LOW);  // Turn the LED off
  delay(1000);                // Wait for 1 second
}

1. No Output Voltage:

   • Cause: Batteries are inserted incorrectly or are discharged.
   • Solution: Check the polarity of the batteries and ensure they are fully charged.

2. Overheating:

   • Cause: Excessive current draw or short circuit.
   • Solution: Verify the circuit's current requirements and check for short circuits.

3. Loose Connections:

   • Cause: Poor contact between the battery terminals and the holder.
   • Solution: Ensure the batteries are seated firmly and the wire connections are secure.

4. Voltage Drop:

   • Cause: High resistance in the wires or terminals.
   • Solution: Use thicker wires if necessary and clean the terminals to ensure good conductivity.

• Always use a multimeter to verify the output voltage before connecting the holder to your circuit.
• If the holder is not functioning as expected, inspect the wire leads for damage or loose solder joints.
• Avoid mixing old and new batteries, as this can lead to uneven discharge and reduced performance.

By following these guidelines and best practices, you can safely and effectively use the 3x Slot Battery Holder 18650 (Seri) in your electronic projects.