How Rechargeable Batteries Work

Battery charging

A battery is a device that stores chemical energy and transforms it into electrical energy needed to power certain applications, usually found in gadgetry or automobile use in the case of mechanical batteries.  The typical battery is cylindrically-shaped, but there have been many variations in its shape and of course, sizes and types. This article will focus on unveiling the simple explanation of how the battery works due to the fact that beyond its very simple form, the battery is filled with intricacy and complexity of detail.

Fundamentally, there are two major types of batteries: the Rechargeable (secondary cell) and the Non-Rechargeable (primary cell). In terms of chemical composition, other subtypes of batteries providing electrical solutions today include:

1.      Disposable Battery

  • Zinc-Carbon type
  • Alkaline battery
  • Silver-oxide battery (commonly used in calculators, watches and hearing aids)
  • Thermal battery (used in military applications)
  • Water-activated type
  • Paper battery (commonly used in pacemakers due to its lightweight advantages)

2.      Reserve Battery (Military applications, recommended for long-term storage)

3.      Traction Battery (designed for automobile use)

4.      Rechargeable Battery

  • Nickel Cadmium battery (motorized equipment)
  • Lithium Ion type (commonly used in digital cameras)
  • Lithium Ion polymer type (PDAs, computers and Bluetooth devices)
  • Sodium Sulfur battery (used to store wind power)

Our focus will be on how rechargeable batteries work, since they are the most commonly used type of battery today. First we have to know how a battery works.

A battery normally has a positive and a negative terminal marked with a (+) and a (-) respectively. In AA and similar types, the opposite ends are its terminals. The positive terminal is also scientifically called the cathode, and the negative terminal is the anode. The fundamental process occurring is the oxidation and reduction of electrons. Electrons are subatomic particles that carry the negative charge that is the end-product of the oxidation process. When we use the battery, attaching the positive and negative terminals to a device, a chemical reaction occurs in the battery where the anode releases electrons (oxidation process) and the cathode absorbs the electrons (reduction process). This produces an electrochemical energy that is conducted by electrolytes. Simply put, when this chemical reaction is triggered with an external device such as an MP3 or a laptop for example, the electrons will travel from the anode to the device, and they will be absorbed by the cathode at the other end, in a cycle that powers the device. This process will continue until both the anode and the cathode run out of chemical reagents.

The same process occurs in a rechargeable battery. The big difference is, and the reason the Rechargeable battery industry is booming today, that this type of battery can completely reverse the process of oxidation-reduction when connected to an electrical outlet. The anode then receives electrons and the cathode produces it, recharging the battery to make it available for reuse. This definitely saves money and time in not making you go back to the grocery store when your non-rechargeable battery runs out.

Although rechargeable batteries last longer than their non-rechargeable counterpart, they also wear out eventually, so it is good to know that you can do the world a big favor by recycling these batteries. A good site that teaches people how to recycle worn out batteries is


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