A 12 volt battery is an irregular battery used in specific electronic applications. Of all the types of batteries, the 12 volt battery is one that looks very different depending on its use. In some ways, it is one of the most diverse of all batteries. It can be large or small, heavy or light. In some cases, they may look nearly like regular AA batteries.
One of the most common uses of a 12 volt battery is for transportation applications, such as in cars and boats. In these cases, the battery may be able to be recharged as current is only needed to start the vehicle. After that, the alternator takes over and runs the electrical system, if it is functioning properly. The alternator also puts a charge back into the battery.
The sizes of 12 volt batteries vary widely based on the amp hours they are designed to produce. They can be very heavy and large, such as those found in cars. They can also be relatively small, such as batteries found in some electrical children's vehicles that run in the front yard.
A 12 volt battery is available as a non-rechargeable alkaline battery or in rechargeable forms. This battery is often used in various outdoor applications that require greater amounts of energy in order to operate as desired. However, it may be recommended to use a rechargeable battery if the electronic item is one that is used regularly. Non-rechargeable batteries can become quite expensive if they must be purchased regularly. Many manufacturers have attempted over the years to reduce the size of the 12 volt battery to one that is easily portable, as some outdoors enthusiasts like to use them to run things like fish finders.
While such electronic devices can be run using an electrical system onboard a boat, there are some anglers who do not have an onboard electrical system. Smaller craft with smaller outboard motors may have a pull start and therefore have no need of an electrical system for its main motor. Therefore, running things like fish finders and oxygenators off a separate battery is the only way to do it.
In such cases where a 12 volt portable battery is used to replace an onboard 12 volt battery, it is usually lighter than a standard version. This is because it is more likely to be transported between uses and consumers will not choose to carry a large, bulky battery. Further, a portable 12 volt battery is usually sealed in a case so that it is waterproof. This is vital, especially in cases where there are boating applications and a substantial amount of water could ruin the battery.