Well the smallest item that makes up a battery is a cell. Cells are joined together within the battery by soldered or welded contacts. These are all then housed in a ‘jacket’ of some kind, whether a wrap or plastic that features the manufacturer’s name, the voltage of the battery, the battery number etc.

Since the invention of the first battery by LeClanche, way back when (We won’t bore you with dates and stuff) the technology of the battery has improved to the point where we are now able to enjoy complete portability in everything from cordless phones, cell phones, laptops, digital cameras, two way radios, etc.

So, below, we have compiled a summary of the different types of batteries available today, the chemistry involved in their manufacture, special features along with some general tips on batteries and battery maintenance.

The list is arranged into two main types: primary batteries and rechargeable batteries (also called secondary batteries).

By far these are the most common battery on the market today. These are the ones you find in corner stores and drug stores, etc. Although primarily dominated by the Energizer and Duracell brand names, other brands such as Panasonic, Maxwell, Ray-o-Vac and Sanyo are gaining more market share with a wider and wider range of battery products.

Alkaline batteries were introduced in the mid 1950’s and were a huge improvement on the traditional general purpose or heavy duty batteries of the time. Why? Because firstly, alkaline batteries pack more ‘punch’ - lasting much longer in applications, such as flashlights and Walkmans, for instance, than before. Secondly, they are not adversely affected by wide fluctuations in temperature, functioning quite well in sub-zero conditions - a feature not associated with general purpose batteries.

Rechargeable battery technology has improved immensely over the past ten years or so. A rechargeable battery is one that offers reversible systems with regard to its electrochemistry and the structure of the electrodes. A primary battery discharges its power just once and then it’s dead. Its internal configuration is generally more simple than rechargeables as it doesn’t have to accommodate numerous charges and discharges. Just a word of caution here, never attempt to charge a primary battery as it is uneconomical and highly dangerous.

Rechargeable batteries offer sound economy, being capable of being charged up to 1,000 times during their lifetime.

Rechargeable batteries (Ni-Cads) or Nickel Cadmium were first manufactured some sixty years ago. They are relatively inexpensive. They are made in part with cadmium, a deadly toxic chemical and should be recycled accordingly. Rechargeable batteries are now also made of Nickel Metal Hydride (NiMH) and Lithium-Ion (Li-Ion) and also Sealed Lead Acid (used mostly in automobile batteries and emergency lighting applications).

If left for long periods of time, all rechargeable batteries will self-discharge.

Batteries should be kept in a cool, dry place away from hazards such as metal touching contacts and excessive heat. Some people store alkaline batteries in their refrigerator and there are mixed opinions about the wisdom and benefits of this. One theory is that the batteries, being cold, will not drain anywhere near as quickly while not in use. However, the refrigerator does have a lot of moisture and, of course, those metal racks could cause problem. And, is it a good idea to have batteries around food? Well, only if they are wrapped very carefully in vapor-proof packaging, otherwise the battery will dry out in the refrigerator environment and die prematurely.

Also, when taken out of the refrigerator, they should be allowed to warm up prior to use. Similarly, batteries in the glove compartment of your car can experience extreme heat in summer, which will dry out the battery quite quickly rendering them useless just when you need them (Murphy’s Law).

Just a further reminder, nickel cadmium batteries can develop what is called ‘memory effect’ if they are not charged and discharged adequately. For all you technical buffs out there this is how it works:

Memory effect is caused by the gathering of bubbles of gas on the cell plates of the battery, when the battery is not adequately charged or discharged. These gas bubbles cling to the battery plates and, of course, reduce the actual area on the plate surface, which reduces their capacity. Also, chemical crystals build-up, and can cause the same problem. Therefore if you charge a battery for just three hours a number of times, when it’s capable of absorbing a six hour charge, it will eventually develop a ‘memory,’ locking it into that level of capacity providing only 3 hours run time. The way to avoid this condition is to fully drain the battery right down before fully charging once again. Be aware that the greatest danger with any type of rechargeable battery is overcharging. If you feel a battery getting hot, either whilst being charged or not, it should be discarded to avoid explosion and fire.

• Generally speaking, alkaline batteries will discharge at approximately 2% per year, while zinc carbon (heavy duty) batteries will release about 4% a year.
• Lithium batteries are very stable and can last up to ten years and beyond in a suitable storage situation, losing only 1% power per year.
• Rechargeable batteries, however, drain very quickly in a storage situation - from between 10% to 25% per month.
• Also temperature can effect this discharge rate. Rule of thumb is - the higher the temperature, the quicker the discharge drainage rate for the battery.

Cordless phone batteries use either nickel cadmium or the newer, nickel metal hydride chemistry. There are dozens of shapes, sizes and voltages on these batteries from a whole host of manufacturers. Over 100 million cordless phones have been sold in the last three years. This is an enormous market for rechargeable nickel cadmium and nickel metal hydride chemistry.

Cell phones use either nickel metal hydride or the new Lithium Ion chemistry. For instance, all of the Nokia batteries including Nokia 2100, Nokia 5100, Nokia 6110, Nokia 232 models are up-grading to Lithium Ion chemistry. Many of the Motorola and Ericsson cell phones are also using a combination of nickel metal hydride and lithium ion chemistry in their line of cell phones.

Laptop computers almost exclusively use Lithium Ion cells made up into powerful battery packs.

Digital cameras have a whole series of Lithium Ion batteries for various models. Also used are high-capacity AA size batteries in nickel metal hydride. Newer models of digital cameras by Sony, Panasonic, JVC etc., are now requiring special Lithium Ion batteries that are ‘smart batteries’ - that is they include micro chips that control and send data on the power left in the battery. These batteries also include a safety feature that protects the battery from over-heating in the event of too much ‘stress’ on the battery pack.

The use of batteries is growing rapidly each year. The new nickel metal hydride batteries, used extensively now in digital cameras, rose 27% in 2001. Lithium Ion is also being introduced in dozens of new applications, but primarily in digital cameras and camcorders. Cell phones, too, are becoming more sophisticated in their need for better chemistry in their battery requirements. Nickel Metal Hydride is slowly being replaced with the newer Lithium Ion battery.

Cordless phone batteries are also getting more powerful with the introduction of the longer range 2.4 ghz models. Cordless phones used to use exclusively Nickel Cadmium batteries, but now all are coming out with Nickel Metal Hydride and in some cases Lithium Ion batteries. The cordless phone market has grown by over 100,000,000 units in three years. The demand for newer and better batteries for these new long-range models will continue to grow.

The battery industry is here to stay and growing by leaps and bounds. As the need for smaller, higher powered batteries emerges in all kinds of applications including cell phones, cordless phones, digital cameras, medical, etc., battery manufacturers will be striving to develop more and more powerful batteries to meet the consumers’ needs.