The automotive battery has been around for a long time and is essentially a device that is capable of producing voltage and delivering electrical current. A standard car battery comprises six separate cells each of which is capable of generating approximately 2.1 volts. The individual cells are connected in series and this means that typically a standard car battery voltage will be around 12.5 to 12.8 volts.
The main purpose of a car battery is to start the engine although it is also required to power the electrical equipment in the vehicle. It therefore comprises an important piece of equipment and it is good practice to make sure it is well maintained to ensure that the voltage and electrical current it produces remains high.
Some of the things to be aware in your battery which could have an impact on the car battery voltage include knowing its age. Older batteries are more likely to lose power or break down. The simple way to check the age is using the markings on the battery. Generally there will be a letter corresponding to the month and a number corresponding to the year such that A8 is January 2008. Check that the terminals are clean, free of rust and securely clamped. Occasionally check the battery case to ensure there is no damage or leaks.
Other things you can do to maintain the car battery voltage and extend the life of the battery is park it in a garage if possible which will keep it out the worst of the weather. In cold weather try and start the engine at least once every day and let the car warm up. Typically batteries lose around 2 to 7% of their charge per day and so running it every day will help to ensure the charge does not drop too much and result in a flat battery.
The power of a car battery is measured by two main criteria. Cold cranking power is a measure of the electrical current a battery produces for 30 seconds at zero degrees Fahrenheit while maintaining a minimum voltage of 7.2v. A higher number means a more powerful battery. The reserve capacity rating is the second criteria and measures the time in minutes taken for the voltage of a fully charged battery to fall below 10.2v at a continuous discharge rate of 25 amps.
To simply check a car battery voltage yourself a voltage meter is required. When the car is stopped and has been left overnight the reading the following day should be between 12.5v and 12.8v. The same test can be done with the engine running and typically a reading of between 13.6v and 14.3v should be achieved for a healthy battery. If the voltage your battery can produce drops then it makes the car harder to start. If the battery is charged and the voltage reading is still low then a new battery may be required in your car.
The battery is an important part of your car engine and is the critical piece of equipment for getting it started. It pays to maintain your battery in good working order as this will ensure that the car battery voltage is maintained and starting the car should not be a problem.