How to Choose the Right Upgrade for Your Car Battery

Your car’s battery comes into consideration when installing aftermarket audio components in your car. It will eventually get to a point when your equipment will require more energy than what your battery can provide. When considering an upgrade for your battery, here are the factors you need to consider to get the right one for your needs:

Two factors to consider to get the right battery for your car

Know Your Car’s Required Voltage

This is the most leisurely consideration when buying a car battery. Almost all cars use a 12-volt battery. The only time you would consider a different voltage is when you are driving a vintage car. Vintage cars, especially those made before the 1960s, run on 6-volt batteries.

Know Your Battery’s Group Number

Also known as battery size, the group number of your battery is the first question that your local car parts shop will ask you. You can easily see this on your car battery as the BCI number or as a particular portion of its model number.

The group number classifies the different car batteries according to their length, width, and height. It also considers the location of its terminals – whether it is a side-post, a recessed top post, or a standard top post battery. Lastly, batteries under the same group size have the same positioning of positive and negative terminal polarities.

battery in your car

What will happen if you put the wrong sized battery in your car?

You would rarely find yourself using a battery outside of the specified group size for your car. Nevertheless, with the different car battery varieties and the requirements of a car’s aftermarket audio component, there are some people who might consider a battery with larger dimensions than what is specified for their car. But, group sizes are strictly followed for a reason.

When installing a larger one, the least of your problems would be the battery not fitting the vehicle’s battery tray. Bigger batteries would most likely come in contact with the other metal parts in your car, which increases the risk of a fire. It would also wear out the original alternator of your car faster since it requires a longer time to keep it charged. Not changing the other electrical components, your wiring, CPU, fuse box, and the starter would break faster due to the higher amperage running through the circuits.    

For batteries smaller than the specified group size for your vehicle, there is also a higher rate of wear and tear for your electrical components – particularly the alternator. This is due to the smaller battery using more energy to start the engine, which would have the alternator charge it for a longer time. You would also have to consider if it would have enough power for the underlying electronics on your vehicle – on-board computer, radio, AC, and lights. 

Know How Much Power You Need

car manual

This is indicated in the battery as CA and CCA. CA, or cranking amps, and CCA, cold-cranking amps, or how much power the battery can put out during tests in the laboratory. Cranking amps indicate the power produced by the battery under 32 degrees Fahrenheit of temperature while cold-cranking amps are the power produced at 0 degrees F. CA would always have a greater value than CCA since cold temperatures decrease the power output of car batteries.

To know how much power your car needs, you would have to refer to your car’s manual. You can find there how much power your engine needs to start. You would want to find one with a higher cold cranking amp. This will ensure that your engine can start in harsh cold temperatures.

There is no limit to how much your battery’s cranking amps exceed the power required by your engine to start. But, you would pay more for a battery that can provide more power.

Get a Battery with the Required Reserve Capacity

The reserve capacity of a battery is how much time it can deliver 25 amps in an environment of 80 degrees F before it is discharged to 10.5 volts. Compared to the short burst output of the CA and CCA, reserve capacity gives you the amount of time it can continuously deliver power.

If you plan to use your electronic components without the engine running, this is a crucial consideration when choosing a car battery.   

To determine how much you need, you add the watts (or the load) of all components operating without the engine. Multiply the reserve capacity of a battery by ten and, then, divide it by the watt load of your electronic components. You will get the amp-hours of the battery for your system. This is the amount of time it can provide electricity to the components before being unable to start the car's engine. 

Choose a Suitable Battery Design

There are three battery designs you can consider for your car: lead-acid battery, AGM battery, and deep-cycle battery.

The lead-acid battery is the typical car battery design. It contains suspended lead plates submerged in diluted sulfuric acid. The reaction between the lead and acid causes the movement of electrons that result in electricity flowing through the terminals.

The absorbed glass mat or AGM battery still uses lead and acid. But, the difference is it uses fiberglass mats to keep the lead plates in place. These batteries are lighter, a bit better in delivering power, and unlikely to leak fluids.

Battery Design

Lastly, the deep-cycle battery, also known as the marine battery, is one used for long periods without recharging. This is the ideal one for vehicles running electronics without the engine running. Its design allows it to trickle power into your electronics for a long time without damaging the battery. Deep-cycle batteries are available in the typical lead-acid design and in AGM design.

If you are running your aftermarket audio or video components without your engine, a deep-cycle battery would probably be the best one for your vehicle. Otherwise, as long as it has the required battery capacity, your car and your aftermarket components can run with a non-deep-cycle lead-acid or AGM battery.

How to Choose the Right Battery Type for Your Car Youtube Video

A Battery Charger will keep your Battery in Top Shape

Yes, you have learned how to choose the right upgrade for a car battery. I also shall mention that a battery charger will keep your battery in top shape. For reference to battery charger brands, please read this post.

When Should You Consider a Second Car Battery?

If your audio equipment requires more reserve capacity than what is available, you might want to consider getting a second battery for your car. You can do this by directly buying two batteries of the same brand, design, and specs. It is also essential that these batteries are from the same production date to ensure that the two are working equally and prevent one battery from degrading more rapidly. 


Automotive battery- wikipedia
Battery Tutorial - hobbyprojects
Convert Reserve Capacity to Amp Hours - sciencing
BU-201a: Absorbent Glass Mat (AGM) - batteryuniversity
DEEP CYCLE BATTERY - crownbattery

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