How to choose the battery for your vehicles, requirements,placement

How to choose the battery  for your vehicles:

•The ability to power the starter to enable minimum starting speed under very cold conditions

•The expected use of the battery for running accessories when the engine is not running

•These two criteria is usually the deciding factor.

•Figure 1.1 shows a graph comparing the power required by the starter and the power available from the battery, plotted against temperature.

•The point at which the lines cross is the cold start limit of the system

•European standards generally use the figure of 18 ° C as the cold start limit and a battery to meet this requirement is selected.

Requirements of Vehicle Battery ;

•The vehicle battery is used as a source of energy in the vehicle when the engine is not running.

•The battery has a number of requirements, which are listed below broadly in order of importance.

•To provide power storage and be able to supply it quickly enough to operate the vehicle starter motor.

• To allow the use of parking lights for a reasonable time.

• To allow operation of accessories when the engine is not running.

• To act as a swamp to damp out fluctuations of system voltage.

• To allow dynamic memory and alarm systems to remain active when the vehicle is left for a period of time.

•The first two of the above list are arguably the most important and form a major part of the criteria used to determine the most suitable battery for a given application.

•The lead-acid battery, in various similar forms, has to date proved to be the most suitable choice for vehicle use. This is particularly so when the cost of the battery is taken into account

•It must be able to carry out all the above listed functions over a wide temperature range

Positioning the Battery :

Several basic points should be considered when choosing the location for the vehicle battery:

• Weight distribution of vehicle components

• Proximity to the starter to reduce cable length

• Accessibility

• Protection against contamination

• Ambient temperature

• Vibration protection

As usual, these issues will vary with the type of vehicle, intended use, average operating temperature and so on.

Extreme temperature conditions may require either a battery heater or a cooling fan.

The potential build-up of gases from the battery may also be a consideration