Batteries

1. What is a LiPo Battery?

• LiPo stands for Lithium Polymer.

• These batteries use a polymer electrolyte instead of a liquid, allowing for flexible shapes and lightweight designs.

2. Why Are LiPo Batteries Preferred for Drones?

• High energy density: More power in a smaller package.

• High discharge rates: Can deliver bursts of current needed for drone motors.

• Lightweight: Critical for flight efficiency and maneuverability.

3. Key Battery Specifications

A. Voltage and Cell Count

• The ‘S’ rating refers to the number of cells in series.

  • Example: 3S = 3 cells in series

• Each cell provides:

  • Fully charged voltage: 4.2V

  • Storage voltage: 3.8V

  • Minimum safe voltage before landing: 3.3V per cell

• Total voltage of a battery = Number of cells × 4.2V (when fully charged)

  • Example: 4S battery = 4 × 4.2V = 16.8V

B. Capacity – mAh

• mAh stands for milliamp hours.

• Indicates how much energy the battery can store.

• Higher mAh = longer flight time, but also more weight.

C. Discharge Rate – C Rating

• The C rating tells you how quickly the battery can safely discharge.

  • Higher C rating = more current delivery

• Formula: Max current = C × Capacity (in Amps)

  • Example: 1000mAh battery with 30C = 30A max discharge

• Too low a C rating can cause:

  • Overheating

  • Battery failure

  • Reduced performance

4. Battery Types and Use Cases

• 1S batteries (3.7V) are typically used in small 65mm drones.

• Larger drones use 3S, 4S, or even 6S batteries depending on power needs.

5. Charging LiPo Batteries

• Always use a LiPo balance charger for batteries with more than 1 cell to charge each cell evenly.

• Charge rate: Typically 1C (e.g., 1500mAh battery = 1.5A charge rate).

• Use LiPo-safe charging bags for fire protection.

• Never leave batteries unattended while charging.

6. Flying with LiPo Batteries

• Monitor voltage during flight.

• Land at or above 3.3V per cell to avoid over-discharge.

• Over-discharging can cause:

  • Swelling

  • Permanent damage

  • Fire risk

7. Battery Safety and Handling

• Main risk of damaged LiPo batteries: Fire hazard

• Signs of damage:

  • Puffiness

  • Physical punctures

  • Overheating

• Store batteries at 3.8V per cell for long-term storage.

• Dispose of damaged batteries properly—never in regular trash.

8. Series vs. Parallel Configurations

• Series: Connect positive to negative to increase voltage.

• Parallel: Connect positive to positive and negative to negative to increase capacity (mAh).

• Used to customize power delivery for specific drone setups.

9. Common Mistakes to Avoid

• Using batteries with too low a C rating

• Flying below 3.3V per cell

• Charging without supervision

• Ignoring puffed or damaged batteries

10. Tools and Accessories

• Voltage checkers

• Balance chargers

• Fireproof charging bags

• Battery logs and labels