Skip to main content

LiPo Charger Boost & I2C Monitor

The UNIT LiPo Charger Boost & I2C Monitor is an advanced charging and monitoring module for single-cell LiPo batteries (3.7V to 4.2V). It integrates a TP4056 charger, an MT3608 voltage booster with output limited to 27V, and a MAX17048 battery monitor over I2C. This module is ideal for applications requiring efficient charging and real-time battery monitoring.

  • LiPo Battery Charging: Two selectable charging currents (200 mA or 1 A) via solder pads.
  • Step-up Converter MT3608: Boosts battery voltage or USB Type C input up to 27V with a maximum output power of 4W, depending on input voltage.
  • Battery Monitoring: The MAX17048 allows real-time battery level and voltage monitoring via I2C.
  • Qwiic/Stemma Compatibility: Includes a JST connector to power Qwiic modules through the system voltage bus (VSYS -> VBAT-6V max).

Module Features​

  • Input Voltage (VIN): USB Type C at 5V or via solder pads (maximum 6V).
  • Battery Charging Voltage: 3.7V nominal (4.2V max).
  • Output Power: Up to 4W through the MT3608 step-up converter, with efficiency depending on input voltage.
  • Connectors:
    • 2.0 mm JST for LiPo battery.
    • 2-pin header (2.54 mm) for battery voltage output.
    • 2-pin header (2.54 mm) for step-up voltage output.
    • 5-pin header for the MAX17048 I2C battery monitor: SDA, SCL, GND, QST (reset), and ALT (alert).
  • Charging Current Selection: Backside solder pad to select 200 mA or 1 A charging current.
  • Qwiic/Stemma Output Compatibility: Connects I2C lines (SDA, SCL) and ground (GND) to the Qwiic/Stemma connector. A jumper pad allows routing system voltage (VSYS) to the Qwiic/Stemma bus, which varies between battery voltage (3.7V) and up to 6V (VIN).
note

Since Qwiic operates at 3.3V, a voltage regulator is recommended after the JST output to step down VSYS to 3.3V, protecting connected Qwiic devices.

Pinout​

Front Pinout​

Back Pinout​

Pin Connection Table​

PINDescriptionFunction on MAX17048
SDAI2C data lineConnect to SDA on the MCU
SCLI2C clock lineConnect to SCL on the MCU
GNDGroundConnect to MCU ground
QSTMAX17048 resetOptional reset pin
ALTBattery level alertOptional alert pin

Additional Specifications​

  • Step-Up Characteristics: Output power and current curves for the MT3608 step-up converter with input voltages of 3.4V, 3.5V, and 3.7V. Efficiency depends on input voltage, with:
    • Output near 27V and a battery at 3.4V: Power limited to ~2-3W.
    • Output near 5V: Stable power output around 4W, even with a battery at 3.4V.
    • Battery voltage above 3.7V: Efficiency improves, maintaining ~4W output.

Usage Note: For optimal performance, use a LiPo battery within 3.7V to 4.2V. Alternatively, provide 5V through USB Type C or VIN pads, with a maximum input of 6V.

Fritzing Models​

Find the Fritzing models for this module in the Fritzing repository, making it easy to integrate into your project diagrams.

You can purchase the UNIT LiPo Charger Boost & I2C Monitor directly from UNIT Electronics.

Documentation​

  • MAX1704X Library: This repository contains a library for controlling the MAX17048 with Arduino IDE and MicroPython. It allows you to read battery voltage, charge percentage, and discharge status.

    MAX1704X Library Repository

  • Technical Documentation: Explore more details in the technical documentation.

    Compatibility​

    • Arduino IDE
    • MicroPython

Getting Started​

Example in MicroPython​

  1. Connections:

    • Connect SDA to the microcontroller's SDA pin.
    • Connect SCL to the microcontroller's SCL pin.
    • Connect GND to the microcontroller's GND.

  2. Library Installation:

    • Download the MAX1704X library from the repository and add it to your project.

  3. Example Code:

from max17048 import MAX17048
from machine import I2C, Pin

i2c = I2C(1, scl=Pin(22), sda=Pin(21))  # Adjust pins as per your MCU
battery_monitor = MAX17048(i2c)

# Read battery voltage
voltage = battery_monitor.get_voltage()
print("Battery Voltage:", voltage, "V")

# Read battery charge percentage
charge = battery_monitor.get_charge()
print("Battery Charge:", charge, "%")

Usage Notes​

  • Charging Current: Use the solder pads to select:
    • 200 mA: Slow charging to extend battery life.
    • 1 A: Fast charging for quicker cycles.

With the UNIT LiPo Charger Boost & I2C Monitor, you can monitor battery status, power Qwiic modules, and achieve stable output voltage for applications requiring higher voltage.

tip

Start your battery charging and monitoring project today!