Hi all,
I'm trying to monitor my state of charge SOC percentage of my lipo battery (3.7V 2000mah) with the use of a MAX10748-G Fuel Gauge connected via I2C. Custom PCB with ESP32-Wroom module.
When using a simple example script to print voltage and SOC% in serial (Arduino IDE) i'm getting a strange constant voltage of appr. 3.33V and a SOC% of 0.06% while Lipo is fully charged.
Any thoughts what might be wrong or causing this issue? (e.g. bad soldering?, I already tried 2 PCBs resulting in same issue).
I would expect a voltage around 4.2V and appr 100% SOC.
PCB Schematic (part of it) attached.
I'm using this lipo battery (103450)
I'm printing the example ino file below.
Thanks for your help.
KR
Mojies
/******************************************************************************
Example1_Simple
By: Paul Clark
Date: October 23rd 2020
Based extensively on:
MAX17043_Simple_Serial.cpp
SparkFun MAX17043 Example Code
Jim Lindblom @ SparkFun Electronics
Original Creation Date: June 22, 2015
This file demonstrates the simple API of the SparkFun MAX17043 Arduino library.
This example will print the gauge's voltage and state-of-charge (SOC) readings
to Serial (115200 baud)
This code is released under the MIT license.
Distributed as-is; no warranty is given.
******************************************************************************/
#include <Wire.h> // Needed for I2C
#include <SparkFun_MAX1704x_Fuel_Gauge_Arduino_Library.h> // Click here to get the library: http://librarymanager/All#SparkFun_MAX1704x_Fuel_Gauge_Arduino_Library
//SFE_MAX1704X lipo; // Defaults to the MAX17043
//SFE_MAX1704X lipo(MAX1704X_MAX17043); // Create a MAX17043
//SFE_MAX1704X lipo(MAX1704X_MAX17044); // Create a MAX17044
SFE_MAX1704X lipo(MAX1704X_MAX17048); // Create a MAX17048
//SFE_MAX1704X lipo(MAX1704X_MAX17049); // Create a MAX17049
double voltage = 0; // Variable to keep track of LiPo voltage
double soc = 0; // Variable to keep track of LiPo state-of-charge (SOC)
bool alert; // Variable to keep track of whether alert has been triggered
void setup()
{
Serial.begin(115200); // Start serial, to output debug data
while (!Serial)
; //Wait for user to open terminal
Serial.println(F("MAX17043 Example"));
Wire.begin();
lipo.enableDebugging(); // Uncomment this line to enable helpful debug messages on Serial
// Set up the MAX17043 LiPo fuel gauge:
if (lipo.begin() == false) // Connect to the MAX17043 using the default wire port
{
Serial.println(F("MAX17043 not detected. Please check wiring. Freezing."));
while (1)
;
}
// Quick start restarts the MAX17043 in hopes of getting a more accurate
// guess for the SOC.
lipo.quickStart();
// We can set an interrupt to alert when the battery SoC gets too low.
// We can alert at anywhere between 1% - 32%:
lipo.setThreshold(20); // Set alert threshold to 20%.
}
void loop()
{
// lipo.getVoltage() returns a voltage value (e.g. 3.93)
voltage = lipo.getVoltage();
// lipo.getSOC() returns the estimated state of charge (e.g. 79%)
soc = lipo.getSOC();
// lipo.getAlert() returns a 0 or 1 (0=alert not triggered)
alert = lipo.getAlert();
// Print the variables:
Serial.print("Voltage: ");
Serial.print(voltage); // Print the battery voltage
Serial.println(" V");
Serial.print("Percentage: ");
Serial.print(soc); // Print the battery state of charge
Serial.println(" %");
Serial.print("Alert: ");
Serial.println(alert);
Serial.println();
delay(500);
}