Wio Terminal Chassis Battery(650mAh)
The Wio Terminal Battery Chassis is a must-have extension board for Wio-Terminal Dev Board as it provides an external power source for Wio Terminal to enhance its portability and compactness. It has a 650mAH rechargeable lithium polymer battery, battery charging/discharging status LED, 4 Grove Analog/Digital Ports, 1 Grove I2C Port, and 1 Grove UART Port, as well as the ABS enclosure for aesthetic and protection. There is also the same Raspberry Pi 40-pin compatible GPIO at the back of the Wio Terminal Battery Chassis for more add-ons!
The new version of the Wio Terminal Battery Chassis has added the Texas Instrument's BQ27441-G1A - self-calibrating, I2C-based fuel gauge for lithium polymer (LiPo) batteries which can be used to measures your battery's voltage to estimate its charge percentage and remaining capacity!
Feature¶
- Built-in 650mAh Rechargeable Lithium Polymer Battery
- Battery charging/discharging status LED
- Battery On/OFF Button
- Built-in BQ27441-G1A fuel gauge for LiPo batteries
- USB Type-C Charging
- Overcurrent protection
- Hiccup mode/Hiccup Protection
- 4 x Grove Analog/Digital Port
- 1 x Grove I2C Port
- 1 x Grove UART Port
- Magnets are hidden inside the enclosure so that it can be stuck on the Whiteboard!
Specification¶
Item | Detail |
---|---|
Power Supply | 4.75V - 5.25V |
Built-in battery | 650mAh |
Charging current | Max: 660mA |
battery board mode | Green LED: Light On is mean the board charing. Red LED: Light on is mean the OTG(battery discharge) enable. Yellow LED: Light on is mean the male interface output/input 5V. |
GPIO output | Max voltage: 5.15V Max current: 380mA |
Trickle charge current | 30mA |
Grove Interface | Grove Analog/Digital * 4, Grove I2C * 1, Grove UART * 1 |
Hardware Overview¶


Precautions¶
-
If the battery is removed while the board is in charge mode, the board will switch to failure mode and the green light blink at a frequency of 1Hz.
-
When the battery board is not in use, please press the button to enter sleep mode and all the LED will off.
Detecting LiPo Battery Status¶
-
Visit the SparkFun_BQ27441_Arduino_Library repositories and download the entire repo to your local drive.
-
Now, the library can be installed to the Arduino IDE. Open the Arduino IDE, and click
sketch
->Include Library
->Add .ZIP Library
, and choose theSparkFun_BQ27441_Arduino_Library
file that you've have just downloaded.
Example Code¶
You may use the following code to read stats from your battery chassis.

#include <SparkFunBQ27441.h>
#include"TFT_eSPI.h"
TFT_eSPI tft;
TFT_eSprite spr = TFT_eSprite(&tft); // Sprite
#define FF17 &FreeSans9pt7b
const unsigned int BATTERY_CAPACITY = 650; // Set Wio Terminal Battery's Capacity
void setupBQ27441(void)
{
// Use lipo.begin() to initialize the BQ27441-G1A and confirm that it's
// connected and communicating.
if (!lipo.begin()) // begin() will return true if communication is successful
{
// If communication fails, print an error message and loop forever.
Serial.println("Error: Unable to communicate with BQ27441.");
Serial.println(" Check wiring and try again.");
Serial.println(" (Battery must be plugged into Battery Babysitter!)");
tft.setTextColor(TFT_RED);
tft.setCursor((320 - tft.textWidth("Battery Not Initialised!"))/2, 120);
tft.print("Battery Not Initialised!");
while (1) ;
}
Serial.println("Connected to BQ27441!");
// Uset lipo.setCapacity(BATTERY_CAPACITY) to set the design capacity
// of your battery.
lipo.setCapacity(BATTERY_CAPACITY);
}
void printBatteryStats()
{
// Read battery stats from the BQ27441-G1A
unsigned int soc = lipo.soc(); // Read state-of-charge (%)
unsigned int volts = lipo.voltage(); // Read battery voltage (mV)
int current = lipo.current(AVG); // Read average current (mA)
unsigned int fullCapacity = lipo.capacity(FULL); // Read full capacity (mAh)
unsigned int capacity = lipo.capacity(REMAIN); // Read remaining capacity (mAh)
int power = lipo.power(); // Read average power draw (mW)
int health = lipo.soh(); // Read state-of-health (%)
// Now print out those values:
String toPrint = String(soc) + "% | ";
toPrint += String(volts) + " mV | ";
toPrint += String(current) + " mA | ";
toPrint += String(capacity) + " / ";
toPrint += String(fullCapacity) + " mAh | ";
toPrint += String(power) + " mW | ";
toPrint += String(health) + "%";
Serial.println(toPrint);
// LCD Graphics
tft.setTextColor(TFT_BLUE);
tft.drawRoundRect(10, 10, 300, 220, 10, TFT_BLUE);
tft.setTextColor(TFT_MAGENTA);
tft.drawString("State of Chage:", 20, 30);
tft.drawString("Battery Voltage:", 20, 55);
tft.drawString("Average Current:", 20, 80);
tft.drawString("Remain Capacity:", 20, 105);
tft.drawString("Full Capacity:", 20, 130);
tft.drawString("Average Power:", 20, 155);
tft.drawString("State of Health:", 20, 180);
// Data
spr.createSprite(80, 170);
spr.fillSprite(TFT_BLACK);
spr.setFreeFont(FF17);
spr.setTextColor(TFT_WHITE);
spr.drawString(String(soc)+" % ", 0, 0);
spr.drawString(String(volts)+" mV ", 0, 25);
spr.drawString(String(current)+" mA ", 0, 50);
spr.drawString(String(capacity)+" mAh ", 0, 75);
spr.drawString(String(fullCapacity)+" mAh ", 0, 100);
spr.drawString(String(power)+" mW ", 0, 125);
spr.drawString(String(health)+" % ", 0, 150);
spr.pushSprite(170, 30);
spr.deleteSprite();
}
void setup()
{
Serial.begin(115200);
tft.begin();
tft.setRotation(3);
tft.fillScreen(TFT_BLACK);
tft.setFreeFont(FF17);
setupBQ27441();
tft.setTextColor(TFT_GREEN);
tft.setCursor((320 - tft.textWidth("Battery Initialised!"))/2, 120);
tft.print("Battery Initialised!");
delay(1000);
tft.fillScreen(TFT_BLACK);
}
void loop()
{
printBatteryStats();
delay(1000);
}