Tips from Used Car Advisor

Car Advisor Tamotsu Todoroki

Hi, this is Tamotsu Todoroki. I am a car advisor of
I write an online column every week to take care of your vehicle. My column is all about something useful and practical for your vehicle. Please have a look once to keep your car in good condition.


How to Choose the Right Size of Car Batteries - Vol.193

For those of us that are not mechanically inclined even the most basic of car fundamentals can prove challenging. However, you should never just guess, approximate, or take a chance when it comes to buying parts for your car. Your car battery is an especially important part of the mechanical system, and finding the right one should be a priority.

We all know that the battery is our cars power source, but familiarizing yourself with its more specific functions can help you understand why selecting the right battery is crucial. The battery is an electrical storage unit that converts chemical energy into electrical energy. This process is completed through a chemical reaction between lead and the battery acid. This is important because certain cars require certain levels of energy, and not every battery can fill this requirement.

When selecting a battery there are three main factors that you should consider: battery group size; cold cranking amps (CCA); and reserve capacity (RC).

Battery Group Size
In order to simplify the process of selecting a battery the automobile industry has standardized the battery sizes. Every vehicle belongs to a "group", which indicates what type of battery is required. The group that a vehicle belongs to is typically determined by the engine size. These different groups will also determine the layout of the negative and positive terminals.

The common nomenclature for these groups can get complex and confusing. The numbers can range from the 20's to the 90's, and looking at a grouping chart can prove to be more of a headache than it is worth. The easiest way to determine your group number is to reference your manual, or ask your mechanic. If you are buying the battery yourself you should always take it out to your car and compare the new battery to your old one.

Cold Cranking Amps
This is essentially the capacity of your battery to start your engine. Your required amount of CCA is determined by two main factors: what you drive and where you live. The type of vehicle that you drive may require more power to start depending on the size of the engine. In addition to this, starting an engine in colder conditions requires more power. If you live in an area that where cold temperatures are the norm then you should be sure that your battery has the capacity to consistently start your vehicle.

Reserve Capacity
The amount of running time that a single battery has in a single load is referred to as reserve capacity. This aspect of the battery has become more important over the years due to increased parasitic drain. Parasitic drain is the sapping of battery energy when the car is turned off. If you have ever left your lights on and were unable to start your car you have experienced the effects of parasitic drain.

Due to the increased amount of technology in modern day cars the demand for a high reserve capacity has increased. This extra capacity is a crucial factor when it comes to your security systems, remote start, and the various computers that maintain memory.

Selecting a suitable battery for your car is not as hard as it sounds. Knowing the various requirements and details of battery selection is great, but if you do not completely understand all is not lost. Your local auto parts store is a great resource to utilize when buying equipment, or installing new parts. When in doubt, ask an expert. However, having a basic knowledge of what is going on will help you relay information to your mechanic, and will make you more comfortable when the time comes to purchase new parts.