Batteries

1. Definition

1.1 Battery

A battery is an electrochemical device that stores and delivers electrical energy through chemical reactions.
It can be:

  • Primary : non-rechargeable (single-use).
  • Secondary : rechargeable.

Battery examples

Battery Symbol

Battery symbol

1.2 Types of Batteries

  • Primary: Alkaline, Lithium (Li-FeS₂, Li-MnO₂).
  • Secondary: Lead-acid, NiMH, Li-ion, Li-Po.
  • Specialty: Coin cells, UPS backup cells, medical-grade cells.

2. Features

  • Voltage rating: e.g., 1.5V, 3.7V, 12V.
  • Capacity: mAh (milliamp-hours) or Ah (amp-hours), indicates energy storage.
  • Rechargeability: whether the chemistry supports multiple charge cycles.
  • Internal resistance: affects current delivery and efficiency.
  • Discharge rate: maximum safe current draw.

4. How to Use

Safety Note

Do not short-circuit, overcharge, crush, or puncture batteries, there is a risk of overheating, fire, or explosion.

4.1 Identify Polarity

  • Positive terminal (+): usually raised or marked with a plus sign.
  • Negative terminal (−): flat, spring contact, or marked with a minus sign.

Battery polarity

4.2 Connecting Batteries

  • Single cell: Connect directly to the circuit.
  • Multiple cells:
    • Series: Increases total voltage (sum of each cell’s voltage).
    • Parallel: Increases capacity (mAh) while keeping voltage the same.
  • Use a battery holder or secure mounting to prevent shorting.

4.3 Applications

  • Portable electronics.
  • Backup and emergency power.
  • Electric vehicles.
  • Renewable energy storage.
  • Robotics and remote systems.

5. Video Explanation

video coming soon