USE AND MAINTANENCE OF CAR BATTERY

Use and maintenance

Fluid level
The majority of batteries today are maintenance free and don't require top up. If the battery has easily detachable tops then a top up may be required from time to time. In this case the tops are simply removed and the cells topped up with distilled or deionised water just above the visible plates.

Tap or rain water should never be used as they both can contain high levels of minerals which will impair battery performance.


Charge and discharge
In normal automotive service the vehicle's engine-driven alternator powers the vehicle's electrical systems and restores charge used from the battery during engine cranking. When installing a new battery or recharging a battery that has been accidentally discharged completely, one of several different methods can be used to charge it. The most gentle of these is called trickle charging. Other methods include slow-charging and quick-charging, the latter being the harshest.

In emergencies a battery can be jump started, by the battery of another vehicle or by a hand portable battery booster.


Changing a battery
In the vast majority of automobiles, the grounding is provided by connecting the body of the car to the negative electrode of the battery, a system called 'negative ground'. In the past this was different, some cars had 'positive ground', but such vehicles were found to suffer worse body corrosion and, sometimes, blocked radiators due to deposition of metal sludge.

When removing a car battery, the ground connection should be removed first and the other connection second. This ensures that a short circuit will not occur by a wrench touching grounded engine parts while disconnecting the other terminal. When connecting a battery, connect the live (or positive) connection first and then the grounded one.


Freshness
Because of "sulfation" , one should never buy a battery that is more than six-months old. In the United States, the manufacturing date is printed on a sticker. The date can be written in plain text or using an alphanumerical code. The first character is a letter that specifies the month (A for January, B for February). The letter "I" is skipped due to its potential to be mistaken for the number 1. The second character is a single digit that indicates the year of manufacturing (for example, 6 for 2006).