Gravity: I2C 3.7V Li Battery Fuel Gauge

3.7V lithium batteries are commonly used in projects, however, the remaining power and voltage of the lithium battery are highly nonlinear. We can only roughly judge whether the battery is full or almost empty according to its voltage.

The Gravity I2C 3.7V Lithium Battery Fuel Gauge employs the Gravity I2C interface, ultra-low operating current and real-time tracking of the relative state of charge (SOC) of the battery through Maxim’s patented algorithm, eliminating the need for full-to-empty relearning and offset accumulation errors. The module also features a low battery power alert interrupt function. When the battery power falls below a specified threshold, the ALR pin generates a falling pulse to trigger the external interrupt of the microcontroller.

You will find it a great help to estimate the battery life by learning the power consumption of the system with this module. In solar-powered projects, it helps to record the status of the battery power change in a day or even months, which benefits to understand the power balance of charge and discharge of the solar system.

Connection Example – Arduino

Connection Example – Raspberry Pi

Features

• Maxim’s Patented Algorithm, accurate voltage and remaining power readings of lithium battery
• No Full-to-Empty Relearning Process, No Offset Accumulation Errors, Plug and Play
• Wide Input Voltage, Compatible with 3.3V and 5V Controllers
• Programmable Low Power Alert Interrupt Threshold
• Battery Reverse Connection Protection

Specifications

• Input Voltage (VCC): 3.3V~6.0V
• Battery Input Voltage (BAT IN): 2.5V~4.2V
• Battery Type(BAT IN): 3.7V Li-polymer/Li-ion battery
• Operating Current: 50 uA
• Interface: Gravity I2C (logic level: 0-3.3V)
• Dimension: 22.0×30.0mm

Resources

• Product wiki

Pinout

Label	Name	Description
+	VCC	Power VCC（3.3~6.0V）
–	GND	Power GND
C	SCL	I2C Clock Signal
D	SDA	I2C Data Signal
ALR	ALRT*	Low battery power alert interrupt (active low)
BAT IN	Battery input	3.7V lithium battery connection port
REV BAT	Battery reverse Indicator	When connection is reversed, REV BAT lights up

Package Contents

• 1x Gravity: I2C 3.7V Li Battery Fuel Gauge
• 1x XH2.54-2P Header
• 1x Gravity 4-pin I2C/ UART Sensor Wire