In today’s world there are few things that function unaided by a battery of some kind. Be it a digital camera, a flashlight, a two-way radio or even a car - batteries are a ubiquitous component of contemporary life. Over the past few decades batteries have become even more prevalent in business, medical, government and military applications. So much so that many businesses spend hundreds of thousands of dollars on battery purchases for the wide variety of portable equipment their workforce may use. Even the average individual relies on battery power for a significant part of their daily routine. However most of us underestimate the importance of a battery till a situation turns desperate. Many of us have experienced the frustrations of a cell phone or laptop or even ipod battery dying at the wrong time! As very few of us actually understand the technology and chemistries behind portable power or how batteries work, here’s a brief introduction for battery buyers.

Though we call all of them batteries, there are two distinct types that exist : “Disposable” batteries (the AA or AAA cells that power your TV remote) and “Re-chargeable” batteries (the batteries that power most portable devices like laptops, cell phones, two-way radios etc.). While disposable or primary batteries cannot be recharged and used again, the secondary or rechargeable batteries by definition can be resurrected to life once their power has been depleted. Rechargeable batteries are widely used in portable devices of all sizes and shapes by individuals, businesses and government agencies world-wide.

Rechargeable or ‘storage’ or ‘secondary’ batteries are an attractive option to disposable batteries because of the the return on investment they offer by virtue of their longevity.

Since rechargeable batteries seem to be all-pervading in modern life, let’s take a deeper look into what makes them tick…literally! We’ll start by understanding what enables them to be reused. Rechargeable batteries are basically ‘electrolytic cells’ – that use an electrolyte, a cathode and anode and make your portable device come alive by producing energy through an electrochemical reaction. The reason this battery can be recharged emerges from the fact that this electrochemical reaction can be reversed with the help of an external electrical source. This external power supply replaces the load in the external circuit and forces the reactions in the cell to run in the opposite direction. With the result the initial reaction is replayed and the cell gets recharged.

The most common types of available rechargeable batteries work on several different chemistries. The prevalent types are:

1. Nickel-Cadmium (Ni-CD): The nickel –cadmium or affectionately referenced as NiCad battery lives the longest and gives more than a whopping 500 charge/discharge cycles. However, this most commonly favored battery for a very wide variety of applications from power tool products to cordless phones comes under fire for its Cadmium toxicity risk and its memory effect. Although cheaper when compared against other secondary batteries, it is considerably heavier.

2. Nickel Metal Hydride (Ni-MH): The Nickel Metal battery is an improvement over the Ni-CD battery because it cuts out the Cadmium anode with a hydride absorbing alloy putting it in the better books of environmentalists. This type of a battery has almost 40% more capacity versus a comparative NiCad battery and shows lesser memory effect. Ever since its debut in 1983, the Nickel Metal Hydride battery has replaced the NiCad in several types of consumer and business electronic devices.

3. Lithium-Ion: The Lithium-Ion battery released in 1990 instantly caught the attention of Laptop manufacturers, cell phone manufacturers and most other portable device manufacturing companies. The reason for this splash was the fact that the Li-Ion could store a large amount of energy without weighing like an African Gorilla! The Li-Ion battery has a longer runtime and enables portable devices to be more realistically ‘wireless’ and offer better value. It came with little or no environment –unfriendly baggage. This high ‘energy to weight’ ratio has made the Li-Ion battery a popular choice of rechargeable batteries for several portable consumer devices such as digital cameras and mp3 players, as well as for several business and industrial applications like professional two-way radios (used by public safety, airlines etc.) and bar code scanners (used heavily in retail environments).

Though these are the leading rechargeable battery chemistries, there are others vying for attention as well. These include the more advanced Lithium based - Lithium polymer battery, sodium-sulfur battery and nickel-zinc among others.

Rechargeable batteries for consumers are easily available in stores across the country. Business and industrial application batteries are less readily available locally than on the internet. In recent times, it has been observed that an increasing number of users and enthusiasts are turning to the Internet to buy rechargeable batteries; the obvious benefits like increased options, better price deals and ease of purchasing being instrumental in the shift.

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