A lithium polymer (Li-Po) battery is a type of rechargeable battery that uses a polymer electrolyte instead of a liquid electrolyte. This design allows for a lightweight, compact, and flexible form factor, making it ideal for applications where size and weight are critical. Li-Po batteries are known for their high energy density, low self-discharge rate, and ability to deliver high current, making them a popular choice in portable electronics, drones, RC vehicles, and electric vehicles.
Below are the general technical specifications for a typical Li-Po battery. Note that specific values may vary depending on the manufacturer and model.
Parameter | Specification |
---|---|
Nominal Voltage | 3.7V per cell |
Fully Charged Voltage | 4.2V per cell |
Discharge Cutoff Voltage | 3.0V per cell |
Capacity Range | 100mAh to several thousand mAh |
Maximum Discharge Rate | 1C to 100C (varies by model) |
Charging Current | Typically 0.5C to 1C |
Operating Temperature | 0°C to 60°C (discharge), 0°C to 45°C (charge) |
Self-Discharge Rate | ~2-5% per month |
Cycle Life | 300-500 cycles (varies by usage) |
Li-Po batteries typically have two or three wires for connection. Below is a table describing the pin configuration:
Pin | Wire Color | Description |
---|---|---|
+ | Red | Positive terminal (V+) |
- | Black | Negative terminal (V-) |
B | Yellow/White | Balance lead (optional, for multi-cell packs) |
Note: The balance lead is used in multi-cell Li-Po packs to ensure each cell is charged evenly.
To power an Arduino UNO with a Li-Po battery, you can use a voltage regulator or a DC-DC step-down module to ensure the voltage is within the Arduino's operating range (7-12V via the barrel jack or 5V via the 5V pin).
// This code reads the voltage of a Li-Po battery connected to an analog pin
// and calculates the battery level. Ensure a voltage divider is used if the
// battery voltage exceeds the Arduino's ADC input range (5V).
const int batteryPin = A0; // Analog pin connected to the battery
const float voltageDividerRatio = 2.0; // Adjust based on your resistor values
const float referenceVoltage = 5.0; // Arduino's ADC reference voltage
void setup() {
Serial.begin(9600); // Initialize serial communication
}
void loop() {
int rawADC = analogRead(batteryPin); // Read the analog value
float batteryVoltage = (rawADC / 1023.0) * referenceVoltage * voltageDividerRatio;
Serial.print("Battery Voltage: ");
Serial.print(batteryVoltage);
Serial.println(" V");
delay(1000); // Wait for 1 second before the next reading
}
Note: Use a voltage divider circuit to scale down the battery voltage if it exceeds 5V. For example, use two resistors (e.g., 10kΩ and 10kΩ) to divide the voltage by half.
Battery Not Charging
Battery Swelling
Short Battery Life
Battery Overheating
Q: Can I use a Li-Po battery without a BMS?
A: It is not recommended. A BMS ensures safe operation by preventing overcharging, over-discharging, and overheating.
Q: How do I dispose of a damaged Li-Po battery?
A: Discharge the battery completely, then take it to a certified e-waste recycling facility.
Q: Can I charge a Li-Po battery with a regular power supply?
A: No, always use a dedicated Li-Po charger to ensure safe and proper charging.
Q: What is the difference between Li-Po and Li-Ion batteries?
A: Li-Po batteries use a polymer electrolyte, making them lighter and more flexible, while Li-Ion batteries use a liquid electrolyte and are generally more robust.