Technology Corner

The Things We Take For Granted

Whether you are using your desktop PC or looking for that fuse in the middle of the night there is one thing that you are almost certainly taking for granted.

The battery.

Like the light bulb, the battery is something that you only ever notice when it fails. It is a much maligned, yet revolutionary piece of equipment that virtually everyone in the world has used at some stage in their lives. We need them to light our way, to entertain us and to keep the pacemaker going, should we be unlucky enough to have one fitted.

A battery's usefulness comes down to its ability to store a voltage or potential difference within it so that it can be used at a later date. At its' heart there is a mixture of chemicals that dictate how many volts the battery can give out and how long it will last.

An experiment in the 1780s led to the invention of the battery. Whilst performing an anatomical experiment, Professor Luigi Galvani noticed that the legs from dead frogs twitched when they were hung on hooks. After a lot of experimentation, Professor Allesandro Volta discovered that it was the fact that the legs were hung on copper hooks from an iron rail. Due to this discovery he went on to produce the first medium for storing electricity. (Although it must be said that there are claims that batteries were in use elsewhere around the world long before this).

This device was known as the Voltaic cell. Professor Volta also discovered that you could increase the output from a cell if you linked it to other identical cells. The battery actually got its name because of this fact, a group of cells formed a battery.

Needless to say the battery has come a long way since then. The cylindrical type that you often buy are correctly known as a dry cell. This is because they are made from an electrolyte that does not need replacing, unlike a car battery that contains acid that needs topping up periodically. These cells only form a battery when they are linked to others. They are normally made of Zinc Carbon which has the chemical properties necessary for producing a constant voltage for a reasonable length of time. Some manufactures also add trace elements into the cell to improve its performance.

Dry cells have one major drawback, and that is that they are not easily recharged. With this in mind the Nickel Cadmium battery was developed. The NiCad battery can be recharged and used again, hundreds of times. However the NiCad battery cannot match the dry cell batteries on a size to voltage ratio. They also cost more to produce and do not last as long.

Recently however, the battery has come to the forefront of our technological exploration. With the development of the Camcorder, Mobile phone and the Laptop computer, batteries became a critical component. The more effective the battery, the longer the device can remain independent of its base (i.e. its charger), thus increasing the flexibility to its user. As a direct result of this an incredible amount of funding is being diverted into the development of more advanced batteries that can a) - supply a voltage for longer and b) - take up a minimum amount of space.

So far the advancements are small, although recently the Lithium Ion battery has made its presence felt within the laptop market. While more costly, its advantages are a greater size to voltage ratio. This allows PC manufactures to decrease the weight and size of their machines.

There is no doubt that new techniques in battery science will make their presence felt before long. Already scientists are working on a battery that can be charged by simply replacing the electrolyte. This holds potential for Automobiles. A car could pull into a garage and drain out the discharged chemicals and then refill the tank with some that are already fully charged.

Another alternative are fuel cells. These act as batteries but actually burn fuel to generate their voltage.

If cars are to stop polluting the planet, an alternative to fuel needs to be found. If they could be powered by the electricity that is stored within a battery of cells, then the noxious fumes could be avoided. There is one minor drawback however. Batteries contain unpleasant chemicals that are not easy to dispose of.

Which would you prefer, the devil or the deep blue sea?

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