Over the years the terms battery size and battery type have become interchangeable. Generally the terms refer to the shape, voltage, and terminal layout of a battery. Also over the years, the world of batteries has evolved including battery chemistry.
Newer battery chemistries such as rechargeable NiCd and NiMH have strained the original common naming conventions. In all old batteries the voltages grew in increments of 1.5 volts. However, newer chemistries like the ones mentioned above on average output 1.25 volts per cell. Because of this difference some devices may not run properly on rechargeable batteries, although most handle them reasonably well. Then there are other devices which have exceptionally high drain rates and require a lithium type battery to run properly.
Battery Brand Models
For devices to run properly another important element is having the correct brand models. Many times manufactures will add a twist to the common battery name as a trick so customers buy their product instead of the competitors. For instance, if your TV remote needs a new battery and inside the battery compartment it says, "Replace with CX472 type battery", many customers will get that specific type, which is a product model for a common battery from a specific company, not knowing that many other companies also make that exact same battery. In some cases with obscure batteries, a specific brand model can become the most common name for a battery 'size'.
Types of Batteries
Generally, batteries can be divided into two types: disposable and rechargeable. Both are widely used. Disposable batteries called primary cells, are intended to be used once and discarded. These are most commonly used in portable devices with low current drain, when away from an alternative power source, or for alarm and communication circuits. Primary cells cannot be reliably recharged because of the battery’s chemical reactions. Below is a list of some primary cells:
- Zinc-carbon battery - mid cost - used in light drain applications
- Zinc-chloride battery - similar to zinc carbon but slightly longer life
- Alkaline battery - alkaline/manganese "long life" batteries widely used in both light drain and heavy drain applications
- Silver-oxide battery - commonly used in hearing aids
- Lithium Iron Disulphide battery - commonly used in digital cameras. Sometimes used in watches and computer clocks. Very long life (up to ten years in wristwatches) and capable of delivering high currents but expensive. Will operate in sub-zero temperatures.
- Lithium-Thionyl Chloride battery - is used in industrial applications, including computers and electric meters. Other applications include providing power for wireless gas and water meters. The cells are rated at 3.6 Volts and come in 1/2AA, AA, 2/3A, A, C, D & DD sizes. They are relatively expensive, but have a proven ten year shelf life.
- Mercury battery - formerly used in digital watches, radio communications, and portable electronic instruments, manufactured only for specialist applications due to toxicity. Meanwhile rechargeable batteries known as secondary cells can be re-charged by applying electrical current, which reverses the chemical reactions that occur in use. These devices are called chargers or rechargers. Different kinds of rechargeable batteries include:
- The "wet cell", the oldest form of rechargeable battery still in modern usage. This battery is notable in that it contains a liquid in an unsealed container, requiring that the battery be kept upright in a well ventilated area to ensure safety while overcharging.
- An improved type of lead-acid battery called a gel battery (or "gel cell") has become popular in automotive industry as a replacement for the lead-acid wet cell.
- More portable rechargeable batteries include several "dry cell" types, which are sealed units used in appliances like mobile phones and laptops.