What Is A Car 12V Battery
What is a 12-volt car battery?
Almost all car batteries are 12-volt, lead-acid batteries. Cars require a lot of power to get them running; the ability of a 12-volt battery to supply high surge currents means that cells have a relatively large power-to-weight ratio, making them a great fit for the automotive industry.
Cars have more technology installed requiring electrical power to operate than ever before. Some of these electrical devices include the ignition system, starter motor, engine controls, cabin controls (heating and cooling and lighting), car security, infotainment systems and most recently, assisted driving systems such as parking sensors and cameras, lane control systems, automatic braking – the list just continues to grow. A 12-volt battery is required to enable these electrical systems to store energy to use them when the engine isn’t running, and the alternator isn’t the source of electrical energy.
12-volt car battery voltage
Modern cars operate using a 12-volt, direct-current electrical system. A 12-volt car battery has a nominal voltage closer to 12.6-volts, as opposed to the 12-volt you typically see on battery packaging. A 12v car battery consist of six electrical cells containing lead plates with oxide coatings, separated by a fixed distance. The electrochemical reaction between the plates being dropped in the battery electrolyte causes the voltage difference between the negative and positive battery terminals.
Cranking amps and cold cranking amps
These two metrics are used for rating the electrical current capacity of a 12-volt battery. Cranking amps (CA) refers to how many amps a battery can provide for 30 seconds, whilst maintaining voltage of at least 7.2-volts, at a temperature of 0°C. Cold cranking amps (CCA) refers to the same as the above but at a temperature of -17°C. Cold cranking amps are a good indication of a battery’s ability to start a car engine in cold temperatures. The electrochemical process that produces battery energy is limited in cold temperatures, which means a car battery will always produce more cranking amps than cold cranking amps.
Battery reserve capacity, amp hour and C20
A battery’s reserve capacity (RC) is a useful indicator of a fully charged battery’s ability to perform (operate electrical systems) when the alternator fails.
Amp hour and C20 metrics are used to indicate how much energy is stored within a 12-volt battery.
12-volt car battery replacement
We trust you are now more informed on 12-volt car batteries and hope that you have found this guide useful.
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