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Bredhurst Receiving and Transmitting Society |
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3. Technical Basics 3c Primary and Secondary Cells Battery v Cell There is always a little confusion over the words "cell" and "battery". What you and I, and probably hundreds of others, thought of as a battery is in fact a cell. Go into a shop and ask for a single 1.5 volt battery and you will be sold a 1.5V battery but in fact what you will have bought is a single 1.5V cell. It is only when two or more cells are connected in series or parallel do those cells become known as a battery. |
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3c.1 Understand that cells store energy in chemical form. Cells have the ability to store electrical energy, else they would be of little use in a torch ! Recall that a primary cell, once discharged, must be properly disposed of. There are two types of cells - PRIMARY and SECONDARY. The primary cell 1.5V is used once and then you must be properly dispose of it !! The primary cell has a typical voltage of 1.5V which can only be discharged and then properly disposed. Within the cell a chemical reaction takes place to provide the electrical energy but this is a one way ticket for the electrons - they cannot be forced back inside once the battery has discharged. Understand that a secondary cell is rechargeable as the chemical discharge process within it is reversible. The secondary cell 1.2V use and recharge - great !! With the secondary cell the chemical reaction within the cell is reversible a number of times by a process called "recharging" which does reverse the chemical reaction. There is however a limit to the number of times this process can take place and it must be carried out strictly in accordance with the manufacturers recommendations. You will probably know a secondary cell as a nicad ( nickle cadmium) or another is the nickel metal hydride as these are both rechargeable cells. |
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