The battery has become our steady travel companion
Battery user groups have asked me to write an edited version of Batteries in a Portable World. The first edition was published in 1997. Much has changed since then.
My very first publication in book form was entitled Strengthening the Weakest Link. It was, in part, a collection of battery articles which I had written. These articles had been published in various trade magazines and gained the interest of many readers. This goes back to the late 1980s and the material covered topics such as the memory effect of NiCd batteries and how to restore them.
In the early 1990s, attention moved to the nickel-metal hydride (NiMH) and the articles compared the classic nickel cadmium (NiCd) with the NiMH, the new kid on the block. In terms of longevity and ruggedness, the NiMH did not perform so well when placed against the NiCd and I was rather blunt about it. Over the years, however, the NiMH improved and today this chemistry performs well for mobile phones and other applications.
Then came the lithium-ion (Li‑ion), followed by the lithium-ion polymer (Li‑ion polymer). Each of these new systems, as introduced, claimed better performance, freedom from the memory effect and longer runtimes than the dated NiCd. In many cases, the statements made by the manufacturers about improvements were true, but not all users were convinced.
The second edition of Batteries in a Portable World has grown to more than three times the size of the previous version. It describes the battery in a broader scope and includes the latest technologies, such as battery quick test.
Some new articles have also been woven in and some redundancies cannot be fully avoided. Much of this fresh material has been published in trade magazines, both in North America and abroad.
In the battery field, there is no black and white, but many shades of gray. In fact, the battery behaves much like a human being. It is mystical, unexplainable and can never be fully understood. For some users, the battery causes no problems at all, for others it is nothing but a problem. Perhaps a comparison can be made with the aspirin. For some, it works to remedy a headache, for others the headache gets worse. And no one knows exactly why.
Batteries in a Portable World is written for the non-engineer. It addresses the use of the battery in the hands of the general public, far removed from the protected test lab environment of the manufacturer. Some information contained in this book was obtained through tests performed in Cadex laboratories; other knowledge was gathered by simply talking to diverse groups of battery users. Not all views and opinions expressed in the book are based on scientific facts. Rather, they follow opinions of the general public, who use batteries. Some difference of opinion with the reader cannot be avoided. I will accept the blame for any discrepancies, if justified.
Readers of the previous edition have commented that I favor the NiCd over the NiMH. Perhaps this observation is valid and I have taken note. Having been active in the mobile radio industry for many years, much emphasis was placed on the longevity of a battery, a quality that is true of the NiCd. Today’s battery has almost become a disposable item. This is especially true in the vast mobile phone market where small size and high energy density take precedence over longevity.
Manufacturers are very much in tune with customers’ demands and deliver on maximum runtime and small size. These attributes are truly visible at the sales counter and catch the eye of the vigilant buyer. What is less evident is the shorter service life. However, with rapidly changing technology, portable equipment is often obsolete by the time the battery is worn out. No longer do we need to pamper a battery like a Stradivarius violin that is being handed down from generation to generation. With mobile phones, for example, upgrading to a new handset may be cheaper than purchasing a replacement battery. Small size and reasonable runtime are key issues that drive the consumer market today. Longevity often comes second or third.
In the industrial market such as public safety, biomedical, aviation and defense, requirements are different. Longevity is given preference over small size. To suit particular applications, battery manufacturers are able to adjust the amount of chemicals and active materials that go into a cell. This fine-tuning is done on nickel-based as well as lead and lithium-based batteries.
In a nutshell, the user is given the choice of long runtime, small size or high cycle count. No one single battery can possess all these attributes. Battery technology is truly a compromise.