The MAX17048 is a battery fuel gauge integrated circuit (IC) designed to provide accurate state-of-charge (SOC) information for single-cell lithium-ion (Li-ion) batteries. Unlike traditional fuel gauges, the MAX17048 employs a sophisticated model-based algorithm to estimate the remaining battery capacity without requiring a current-sense resistor. This makes it highly efficient and easy to integrate into compact designs.
This circuit is a multi-sensor data acquisition system that uses a Nucleo WB55RG microcontroller to interface with a digital temperature sensor (TMP102), a pulse oximeter and heart-rate sensor (MAX30102), and a 0.96" OLED display via I2C. Additionally, it includes a Sim800l module for GSM communication, powered by a 3.7V LiPo battery.
Open Project in Cirkit Designer
This circuit features an ESP32-WROOM-32UE microcontroller as the central processing unit, interfacing with a variety of sensors and modules. It includes a MAX30100 pulse oximeter and heart-rate sensor, an MLX90614 infrared thermometer, an HC-05 Bluetooth module for wireless communication, and a Neo 6M GPS module for location tracking. All components are powered by a common voltage supply and are connected to specific GPIO pins on the ESP32 for data exchange, with the sensors using I2C communication and the modules using UART.
Open Project in Cirkit Designer
This circuit features a SparkFun ESP32 Thing Plus microcontroller interfaced with an Adafruit ICM20948 9-axis motion sensor via an Adafruit TXB0104 4-channel bi-directional level shifter. The ESP32 reads data from the ICM20948 sensor, calculates orientation angles such as pitch, roll, yaw, and azimuth, and outputs these values to the serial monitor. The level shifter ensures compatibility between the 3.3V logic levels of the ESP32 and the 1.8V logic levels required by the ICM20948.
Open Project in Cirkit Designer
This circuit features an ESP32 Wroom Dev Kit microcontroller interfaced with an MCP23017 I/O expansion board via I2C communication, utilizing GPIO 21 and GPIO 22 for SDA and SCL lines, respectively. A vibration motor is controlled by an NPN transistor acting as a switch, with a diode for back EMF protection and a resistor to limit base current. The ESP32 can control the motor by sending signals to the MCP23017, which then interfaces with the transistor to turn the motor on or off.
Open Project in Cirkit DesignerThe MAX17048 communicates via an I2C interface, making it compatible with a wide range of microcontrollers and systems.
| Parameter | Value |
|---|---|
| Operating Voltage Range | 2.5V to 4.5V |
| Battery Type Supported | Single-cell lithium-ion |
| Communication Interface | I2C (7-bit address: 0x36 default) |
| Supply Current | 1.2µA (typical) |
| SOC Accuracy | ±1% |
| Operating Temperature Range | -40°C to +85°C |
| Package Type | 6-pin µDFN (1.5mm x 1.5mm) |
| Pin Number | Pin Name | Description |
|---|---|---|
| 1 | VDD | Power supply input (2.5V to 4.5V). |
| 2 | SDA | I2C data line. Connect to the microcontroller. |
| 3 | SCL | I2C clock line. Connect to the microcontroller. |
| 4 | GND | Ground. Connect to the system ground. |
| 5 | THRM | Optional thermistor input for temperature monitoring. |
| 6 | BAT | Battery connection. Connect to the positive terminal of the battery. |
Below is an example of how to interface the MAX17048 with an Arduino UNO to read the state-of-charge (SOC):
#include <Wire.h> // Include the Wire library for I2C communication
#define MAX17048_ADDRESS 0x36 // I2C address of the MAX17048
void setup() {
Wire.begin(); // Initialize I2C communication
Serial.begin(9600); // Initialize serial communication for debugging
}
void loop() {
uint16_t soc = readSOC(); // Read the state-of-charge
float percentage = soc / 256.0; // Convert to percentage (0-100%)
Serial.print("Battery SOC: ");
Serial.print(percentage);
Serial.println("%");
delay(1000); // Wait for 1 second before the next reading
}
uint16_t readSOC() {
Wire.beginTransmission(MAX17048_ADDRESS); // Start communication with MAX17048
Wire.write(0x04); // Send the register address for SOC
Wire.endTransmission(false); // End transmission without releasing the bus
Wire.requestFrom(MAX17048_ADDRESS, 2); // Request 2 bytes of data
uint8_t msb = Wire.read(); // Read the most significant byte
uint8_t lsb = Wire.read(); // Read the least significant byte
return (msb << 8) | lsb; // Combine the two bytes into a 16-bit value
}
Code Explanation:
readSOC() function reads the SOC register (address 0x04) from the MAX17048.No I2C Communication:
Incorrect SOC Readings:
Device Not Detected on I2C Bus:
Temperature Monitoring Not Working:
Q: Can the MAX17048 be used with batteries other than lithium-ion?
A: No, the MAX17048 is specifically designed for single-cell lithium-ion batteries.
Q: What is the typical accuracy of the SOC readings?
A: The MAX17048 provides SOC readings with an accuracy of ±1%.
Q: Is it necessary to use the THRM pin?
A: No, the THRM pin is optional. If temperature monitoring is not required, it can be left unconnected.
Q: Can the MAX17048 operate at voltages below 2.5V?
A: No, the operating voltage range is 2.5V to 4.5V. Operating below this range may result in incorrect readings or malfunction.
This documentation provides a comprehensive guide to understanding, using, and troubleshooting the MAX17048 battery fuel gauge IC.