How to Use MAX17048 Breakout: Examples, Pinouts, and Specs

The MAX17048 Breakout (Adafruit Part ID: 5580) is a compact and efficient breakout board featuring the MAX17048 battery fuel gauge IC. This component provides accurate battery state-of-charge (SoC) information using a simple I2C interface, making it ideal for battery-powered projects. The MAX17048 eliminates the need for complex battery characterization or calibration, offering a plug-and-play solution for monitoring lithium-ion (Li-ion) or lithium-polymer (LiPo) batteries.

• Battery-powered IoT devices
• Wearable electronics
• Portable medical devices
• Robotics and drones
• Power banks and battery management systems

The MAX17048 Breakout is designed for ease of use and integration. Below are its key technical details:

The MAX17048 Breakout has six pins, as detailed below:

The MAX17048 Breakout is straightforward to use in a circuit. Follow the steps below to integrate it into your project:

1. Power Supply: Connect the VIN pin to a 3.3V or 5V power source and the GND pin to ground.
2. Battery Connection: Connect the BAT pin to the positive terminal of the Li-ion or LiPo battery.
3. I2C Interface: Connect the SCL and SDA pins to the corresponding I2C pins on your microcontroller.
4. Optional ALERT Pin: If you want to use the ALERT feature, connect the ALERT pin to a GPIO pin on your microcontroller.

• Ensure the battery voltage is within the 2.5V to 4.5V range for accurate readings.
• Use pull-up resistors (typically 4.7kΩ) on the SCL and SDA lines if your microcontroller does not have internal pull-ups.
• Avoid connecting the BAT pin to a power supply; it is designed specifically for battery input.

Below is an example Arduino sketch to read the battery state-of-charge using the MAX17048 Breakout:

#include <Wire.h>

// MAX17048 I2C address
#define MAX17048_ADDRESS 0x36

void setup() {
  Wire.begin(); // Initialize I2C communication
  Serial.begin(9600); // Start serial communication for debugging

  // Check if the MAX17048 is connected
  Wire.beginTransmission(MAX17048_ADDRESS);
  if (Wire.endTransmission() != 0) {
    Serial.println("MAX17048 not detected. Check connections.");
    while (1); // Halt execution if the device is not found
  }
  Serial.println("MAX17048 detected successfully.");
}

void loop() {
  float soc = readStateOfCharge(); // Read battery state-of-charge
  Serial.print("Battery State-of-Charge: ");
  Serial.print(soc);
  Serial.println("%");
  delay(1000); // Wait 1 second before the next reading
}

float readStateOfCharge() {
  Wire.beginTransmission(MAX17048_ADDRESS);
  Wire.write(0x04); // Register address for state-of-charge
  Wire.endTransmission(false); // Send repeated start condition
  Wire.requestFrom(MAX17048_ADDRESS, 2); // Request 2 bytes of data

  if (Wire.available() < 2) {
    return -1; // Return -1 if data is not available
  }

  uint16_t socRaw = (Wire.read() << 8) | Wire.read(); // Combine MSB and LSB
  return socRaw / 256.0; // Convert to percentage
}

• The readStateOfCharge() function reads the state-of-charge register (0x04) and converts the raw data into a percentage.
• Ensure the I2C address (0x36) matches the default address of the MAX17048. If the address is different, update it in the code.

1. MAX17048 Not Detected

   • Cause: Incorrect wiring or I2C address mismatch.
   • Solution: Verify the connections to the SCL and SDA pins. Ensure pull-up resistors are present if required. Check that the I2C address in the code matches the device's address.

2. Incorrect State-of-Charge Readings

   • Cause: Battery voltage outside the supported range or poor battery connection.
   • Solution: Ensure the battery voltage is between 2.5V and 4.5V. Check the BAT pin connection.

3. ALERT Pin Not Functioning

   • Cause: ALERT pin not configured or monitored in the code.
   • Solution: Configure the ALERT pin as an input on the microcontroller and monitor its state.

Q: Can the MAX17048 Breakout monitor multiple batteries?
A: No, the MAX17048 is designed to monitor a single Li-ion or LiPo battery.

Q: Do I need to calibrate the MAX17048?
A: No, the MAX17048 uses Maxim's ModelGauge algorithm, which eliminates the need for calibration.

Q: Can I use the MAX17048 with a 5V microcontroller?
A: Yes, the breakout board is compatible with both 3.3V and 5V logic levels.

Q: What happens if the battery voltage drops below 2.5V?
A: The MAX17048 may provide inaccurate readings or stop functioning. Ensure the battery voltage remains within the specified range.