Driver Knowledge Tests

10 things to consider when buying a car battery

Most car batteries are limited to a lifespan of 3-5 years depending on the nature of the trips and climatic conditions. Here are a few tips on what to look out for when buying a new battery for your car.

1. Battery Size

Car batteries are divided into group sizes which indicate the length, width, and height of the battery. You can find out the battery size required by checking the owner’s manual or consulting with your mechanic and then making a comparison between car batteries. The right battery size is the one that fits perfectly in the battery tray securing the battery and preventing damage arising from vibrations.

2. Battery Freshness

Battery freshness is indicated by a code on the battery which consists of a letter and number. The letter stands for the month whereas the number stands for the year of manufacture e.g. B/4 stands for February 2014. You should never buy a battery which is older than six months from the date of manufacture.

3. Reserve Capacity

This refers to the amount of time that the battery can run on its own power without the engine and before discharge. Having a high Reserve Capacity helps the car through tough situations such as a noncompliant engine, alternator failure and accidentally leaving lights on.

4.Power Requirement

This refers to Cold Cranking Amps (CCA) and Cranking Amps (CA). Cranking Amps is the energy required to start a vehicle at temperatures of 32 degrees Fahrenheit while Cold Cranking Amp points to the ability of the battery to start a car at 0 degrees Fahrenheit. CCA applies for cold climates and batteries with higher CCA are recommended.

5. Maintenance

There are two scenarios here: the low maintenance and the maintenance-free type. The maintenance-free car battery is usually sealed and the liquid electrolyte can run throughout the battery life with no need for replacement. Low maintenance batteries are unsealed with caps that allow you to add distilled water occasionally.

This car battery diagram shows the positive and negative terminals and the caps where you can maintain it with distilled water.


It is advisable to consider warranties and choose a battery with a long period of free replacement. Warranty periods are measured by a figure combining the free replacement period and the prorated period. The prorated period allows for partial reimbursement of the purchase sum of the battery for a limited period of time.

7. Type and Position of Terminals

The position of the positive terminal affects the polarity of the car and there is a risk of shorting if the positive terminal contacts with the metal shell of the car. It is therefore very crucial to check what side the positive terminal is located whether right or left depending on the type of car.

Ensure that the terminals are the right way around (red is positive) and that the battery is securely screwed down.

8. Ampere Hour (Ah)

This refers to how much electricity the battery can store (capacity). A higher Ah means that the battery can maintain a load for a long time thus chances of the battery running out are less.

9. Battery Life

You can check the battery life of your current battery at an auto parts store or battery specialist. This will help you know if you need a new battery or just a maintenance procedure.

10. Previous Experience

Before buying a battery, consider your own previous experience with the battery type. A battery which served you for a log time without issues is preferable, and you can always compare this experience with friends.


Darren is an expert on driving and transport, and is a member of the Institute of Advanced Motorists

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