Car batteries come in different types and sizes. Nowadays, there is a wide range of car batteries in the market with different specifications. With the advancement in technology, the automobile industry is also developing. So, new batteries are designed to suit new models of cars. This makes it is confusing to determine different car battery types and sizes. So, if you’re unable to differentiate between various car batteries then read further to get clarity.

Car batteries differ on factors of configuration, cost, maintenance, power capacity, charging speed, and longevity. The main types of car batteries that are commonly used in vehicles are flooded or lead-acid battery, gel, AGM, and a lithium-ion battery. Also, the size of a car battery can be determined with the help of its group size.

What are the main types of car batteries?

Broadly speaking, there are mainly two categories of car batteries based on their function. First is the Starting Lighting Igniting (SLI) battery and the next is the Deep-cycle battery. An SLI battery is the one that helps you start your car by giving a high start power. Unlike a deep-cycle battery, it is not equipped with multiple charge cycles. Moreover, it has a short charge cycle and it discharges soon. A Deep-cycle battery on the other hand provides continuous power to your vehicle and helps in starting as well as running it. It can be repeatedly charged and discharged throughout its lifespan without any damage.                                           

What are the various kinds of deep-cycle car batteries?

The following are the major kinds of deep-cycle car batteries used in today’s time:

1) Wet lead-acid battery:

The most common type of battery is the wet lead-acid battery or the flooded battery. It is a traditional car battery that has been tried and tested for many decades now. A lead-acid battery is affordable and will fit right in your budget. It is a long-lasting deep cycle battery. However, a disadvantage of this car battery, when compared to a sealed battery, is that it requires maintenance. Here, you need to manually fill each battery cell with distilled water at regular intervals. Other constraints in this kind of car battery are chances of acid leakage and release of fumes and gas. To overcome this limitation and minimize the chances of an accident, you need to install the battery carefully.

2) Sealed car battery:

A sealed car battery is a battery that is technically advanced and automated. It is also known as Valve Regulated Lead-Acid (VRLA) battery. It is has a relief valve and is completely sealed with no acid or gas leak problems. So, a sealed battery can be mounted anywhere or in any position. It is relatively low on maintenance but an expensive car battery. The sub-categories of a sealed battery are:

(a) Gel Battery:

A Gel battery is an improvised version of the lead-acid battery. It is a maintenance-free, sealed, and safer to use car battery. A Gel battery uses silica which when mixed with electrolyte inside the battery produces a gel-like substance. The formation of the gel prevents its leakage and creation of fumes. Hence it is safer to use a gel battery. Moreover, it can resist vibration and be mounted in any place. However, given the advantages, a gel battery is costly and takes time to charge.

(b) Absorbed Glass Mat (AGM) Battery:

It is also a type of sealed battery. An AGM battery is a highly advanced lead-acid battery. The specially designed fiberglass mats in the battery separate the electrolyte and lead plates. The electrolyte is firmly packed in the cells of the battery which makes it less prone to leakage. It is best suited for places having cold temperatures as its Cold Cranking Amps (CAA) is quite high. An AGM battery also charges faster than a flooded lead-acid battery. One of the major drawbacks of an AGM battery is its relatively higher cost. Further, it is sensitive to overcharging. However, similar to a Gel battery, it has a longer life, is maintenance-free, and vibration resistant too.

3) Lithium-ion Battery

A Lithium-ion battery is the latest battery technology in the market. It is another type of maintenance-free car battery. Unlike a flooded battery, it doesn’t require water level monitoring and refilling. Its lifespan is the longest among all batteries. It can be used for more than 8-10 years and it is eco-friendly as it doesn’t use toxic heavy metals like lead and nickel. It is a highly efficient battery that can use up to 80% of its total power capacity. One main limitation of this battery is that it is the costliest of all car batteries. But it gives relatively more power and lasts for a longer duration. So given the advantages, the high quality of a lithium-ion battery is worth its price.






1) Power capacity usage

Very low



Very high

2) Maintenance


Not Required

Not Required

Not Required

3) Recharging rate

Very slow



Very fast

4) Cost




Very costly

5) Longevity subject to adequate maintenance

3-5 years

5-7 years

6-8 years

10+ years

What are the different sizes of car batteries?

There are multiple sizes of car batteries. However, there is no need to physically measure the battery to know about its dimensions. For this, you just need to check the group size which is printed on its label, and match it with your car manual. The ‘BCI group size’ of a battery helps in determining its exact dimensions i.e., its height, weight, and length. Moreover, it also mentions the terminal’s configuration, whether they are located on the top or on the sides. The most standard group size of car batteries are 24, 24F, 25, 27, 31, 34, 35, 51, 51R, 59, 65, 70, 75, and 78.

It is extremely important to see the group size every time you replace your car battery. This will help you in buying a battery with the correct group number so that it perfectly fits in your car. For example, if a BCI 24 battery installed in your vehicle dies then it has to be replaced only with a BCI 24 battery irrespective of its type. 

Thus, these were the various car battery types and sizes. We hope that now you can easily make out the difference between various car batteries. It will surely help you decide which one is the best for your car.

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