MAX17043 Single-Cell Li-ion Battery Fuel Gauge and Power Detection Alarm Module

MAX17043 Single-Cell Li-ion Battery Fuel Gauge and Power Detection Alarm Module is an ultra-compact host-side battery fuel-gauge breakout board built around the Analog Devices / Maxim MAX17043G+U IC. Utilizing Maxim’s patented ModelGauge™ algorithm, it continuously tracks the voltage and state-of-charge (SOC %) of any single-cell (1S 3.7V/4.2V) lithium-ion or lithium-polymer battery over a two-wire I2C bus without requiring current-sense shunt resistors or full charge/discharge learning cycles.

Key Features:

• Patented ModelGauge™ SOC Algorithm: Accurately calculates remaining battery percentage (0%–100%) and cell voltage (1.25mV resolution) directly from dynamic voltage modeling—no external sense resistor needed.
• Standard I2C Digital Interface: Communicates seamlessly with Arduino, ESP32, STM32, and Raspberry Pi over 100kHz/400kHz I2C (fixed 7-bit address `0x36`).
• Programmable Low-Battery Alert Interrupt (ALRT): Open-drain active-low `ALRT` pin triggers a hardware microcontroller interrupt whenever remaining battery capacity drops below a user-defined threshold (configurable from 1% to 32%).
• Ultra-Low 50µA Quiescent Current: Draws microamps from the battery during active monitoring and supports a software sleep mode for multi-month IoT deployments.
• Factory-Calibrated Precision: Eliminates ADC voltage-divider drift and non-linear Li-ion discharge curve guesswork.

Technical Specifications:

• Fuel Gauge IC: Maxim Integrated / Analog Devices MAX17043G+U (TDFN-8)
• Supported Battery Chemistry: 1S (Single-Cell 3.7V Nominal / 4.2V Max) Li-ion & LiPo
• Operating Supply Voltage: 2.5V to 4.5V DC (Powered Directly from Battery)
• Voltage Measurement Resolution: 1.25 mV (12-Bit Sigma-Delta ADC, ±30mV Accuracy)
• Communication Bus: I2C (Standard 100kHz & Fast 400kHz | I2C Address: `0x36`)
• Low-Battery Alert Threshold: Programmable from 1% to 32% SOC
• Operating Current: ~50 µA Typical
• Operating Temperature Range: -40°C to +85°C

Mechanical Specifications:

• PCB Material: FR-4 Double-Sided Blue Fiberglass Board
• Connectors: 2.54mm Pitch Header Pins + JST-PH 2.0mm Battery Socket Pads

Dimensions:

• Length: ~22 mm to 28 mm
• Width: ~10 mm to 17 mm
• Height: ~4 mm
• Weight: ~2.5 g

Pinout and Wiring:

• BAT+ / VCC & BAT- / GND: Connect directly across the 1S 3.7V Li-ion/LiPo battery terminals.
• SDA & SCL: Connect to microcontroller I2C data and clock pins.
• ALRT: Active-low open-drain interrupt output (connect to an MCU wake/interrupt pin to wake ESP32 from deep sleep when battery is low).
• QSTRT: Quick-Start input pin (forces an instant recalibration of the ModelGauge filter after swapping batteries).

Datasheet Reference:

• Primary IC Datasheet: MAX17043 / MAX17044 Compact, Low-Cost 1S/2S Host-Side Fuel Gauges Datasheet (PDF)

Commonly Used in:

• ESP32 / ESP8266 Solar & Battery-Powered Weather Stations
• Handheld OLED Gaming Consoles and Portable Instruments
• LoRaWAN Remote Sensor Nodes with Deep-Sleep Battery Telemetry
• Wearable Health Monitors and Smart Home Sensors

Applications:

• Reports exact battery percentage (`%`) and cell voltage (`V`) to Home Assistant, MQTT dashboards, or OLED screens over I2C using the SparkFun/DFRobot MAX17043 Arduino library.
• Wakes an ESP32 from deep sleep via the `ALRT` pin when the battery drops below 10% so it can transmit a low-battery warning before shutting down.
• Replaces inaccurate resistor voltage dividers on microcontroller ADC pins.

Equivalent Models:

• ZB2L3 18650 Li-ion Lithium Battery Capacity Tester: Standalone benchtop mAh discharge capacity analyzer with LED display.
• 1S 3.7V 3A Li-ion BMS PCM Battery Protection Board: Hardware MOSFET cut-off protection strip for 1S cells.

Package Includes:

• 1 × MAX17043 Single-Cell Li-ion Battery Fuel Gauge and Power Detection Alarm Module