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Li-ion Battery

A standard 3.7V Lithium-ion battery cell used for powering portable and high-current projects.

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18650 Cell

Lithium-ion batteries offer incredible energy density, making them the standard choice for portable robotics, drones, and IoT devices. A single cell operates nominally at 3.7V, peaking at 4.2V when fully charged and dropping to around 3.0V when empty.

Power ComponentsEnergyPortable

Overview

Unlike standard 1.5V alkaline AA batteries, Li-ion cells provide enough voltage (3.7V) to power 3.3V logic systems natively (like ESP32 or 3.3V Arduino boards) using a simple linear regulator, and they can deliver massive amounts of current for motors.

Pin Reference

Pin	Type	Description
VCC (+)	power	Positive terminal. Outputs the current battery voltage (3.0V - 4.2V).
GND (-)	power	Negative terminal. Ground reference.

Configurable Attributes

Attribute	Type	Default	Description
capacityMah	number	2000	Total maximum charge capacity of the battery in mAh.
currentChargeMah	number	2000	The current remaining charge in the battery in mAh.
nominalVoltage	number	3.7	The nominal voltage rating of the cell.

Working Principle

In the simulator, the Li-ion battery acts as an ideal voltage source that drops its voltage dynamically as the currentChargeMah depletes, matching a typical Li-ion discharge curve. If it drops below 3.0V, it stops providing useful power until recharged.

Wiring Diagram

Example Arduino Code

// Reading the battery voltage via a voltage divider (assuming a 1:2 divider on A0)
const int batteryPin = A0;

void setup() {
  Serial.begin(9600);
}

void loop() {
  int rawADC = analogRead(batteryPin);
  
  // Calculate voltage: (ADC / 1023) * 5.0V * 2 (multiplier for the 1:2 divider)
  float voltage = (rawADC / 1023.0) * 5.0 * 2.0; 
  
  Serial.print("Battery Voltage: ");
  Serial.print(voltage);
  Serial.println(" V");
  
  if(voltage < 3.2) {
    Serial.println("WARNING: Low Battery!");
  }
  
  delay(1000);
}

Simulation Notes

• You can simulate a charging circuit by providing a higher voltage to the VCC pin (e.g., via the TP4056 charger module component), which will slowly increase currentChargeMah over time.
• The battery tracks the current draw of all components connected to it and depletes appropriately in real time.

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