by Staff Writer
Every portable electronic device, from your camera to your portable DVD player, runs on batteries. This batteries glossary is meant to help you be more knowledgeable about battery terminology, so you can choose replacement camera batteries or other battery packs for any of your devices, whether they're rechargeable batteries or one-use only.
Cell: Basic electrochemical unit in a battery that stores and generates energy.
Electrode: A conductor through which the current enters and leaves the electrolyte. The electrochemical reactions that generate electrical current for the battery take place at the electrodes.
Anode: The positive electrode in a battery that attracts negatively charged particles.
Cathode: The negative electrode in a battery that attracts positively charged particles.
Electrolyte: The conductor in a battery that transports ions between the electrodes to convert the chemical energy into electrical energy. A battery with an electrolyte in the form of a moist paste is a dry-cell battery; a wet-cell battery has a liquid electrolyte. Dry-cell batteries are commonly used in portable electronics such as digital cameras and camcorders, but are steadily being replaced by rechargeable lithium-ion batteries.
Alkaline: A dry-cell battery that comes in the standard sizes of AAA, AA, C and D. Alkaline batteries are usually one-use batteries and have to be recycled. They have an alkali solution of potassium hydroxide for the electrolyte. Alkaline batteries are more resistant to leaks than other dry-cell batteries.
Nickel Cadmium (Ni-Cad): One of the early forms of rechargeable batteries, the Ni-Cad battery features rolled layers of nickel and cadmium. These batteries are available in standard battery sizes. They can recharge many times and are more durable than other rechargeable batteries. However, Ni-Cads do have a memory effect, which requires you to completely drain them before recharging, or suffer a loss in battery life.
Nickel Metal Hydride (Ni-MH): This is another rechargeable battery can be recharged up to 1000 times. The Ni-MH battery offers a longer running time than the Ni-Cad battery and is popular for phone batteries. The anode is made of hydrogen and the cathode is made of nickel hydroxide.
Lithium Ion (Li-ion): A rechargeable battery with lithium and carbon electrodes. Common as cell phone, music player and laptop batteries, the great advantage of lithium batteries is that they pack a lot of energy into a small size. Lithium batteries feature less weight per unit of energy density than the Ni-Cad battery and maintain their charge well even after a long period of being unused. Li-ion batteries do not suffer from memory effect. They are sensitive to heat and have a short shelf-life of just two to three years.