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Can You Use A Deep Cycle Battery In A Car? [ Here’s The Answer ]

Can You Use A Deep Cycle Battery In A Car? [ Here’s The Answer ]

A deep cycle battery (or also called a marine battery) and an available car battery are fabricated with specific capabilities to match the engines’ requirements.

As its name suggests, a marine battery runs and powers the engine of boats, and a car battery powers the engine of a car.

Now, some people often think that these two batteries are interchangeable, and thus, if required, you can use a deep cycle battery in place of a car battery.

However, there remains some doubt that this article will surely clear all those doubts. By the end of the article, you’ll get to know whether you can use a deep cycle battery in a car or not.

Can you use a deep cycle battery in a car?

Be it a deep cycle battery or a regular car battery, and both have the majority of the critical elements identical.

These are a positive/negative terminal and a connecting fluid like an acid. So, this may prompt you and other individuals to consider interchanging them.

However, you should not. One of the main reasons behind this is that a car battery tends to release high currents in a shorter period while a marine battery releases smaller currents for extended periods.

This one particular reason emphasizes why a deep cycle battery favors boats rather than four-wheeler like cars.

Besides this, there are several other reasons you shouldn’t use a deep cycle battery in your car, and even if you wish to do so, what are the specific parameters the marine battery must fulfill.

Why should you not use a deep cycle battery in your car?

So, now it’s clear that you cannot use any ordinary available deep cycle battery instead of a car battery.

You need to have a specially designed battery to match your car’s requirements, even if you do. So, first, let’s understand why no ordinary marine battery fits suitably for usual car operations.

1. Initial and continuous currents

A car battery has numerous thin plates that produce high current for a short period to start the engine and get the motor working.

It is a crucial requirement in the case of cars. Hence, a car battery is also called a starter battery.

Contrarily, a marine battery features thicker metal plates to discharge low currents for extended periods.

It forms a crucial aspect as a marine battery keeps the engine running and lights, gauges, pumps, etc. So, both are not interchangeable in this regard.

2. Shorter vs. longer use

Recall the construction of both the batteries. Making a general car battery inclines better for a shorter use as thin metal plates are not useful for long and extended uses.

Such batteries can also warp after a short period at such high currents that it manages to deliver.

On the other hand, a marine battery tends for a more in-depth and prolonged use, thanks to its thick metal plates. So, this aspect again strengthens the debate against the use of deep cycle batteries in a car.

3. Maintenance of batteries

Though the elements are more or less the same, the charging methods are entirely different. A deep cycle battery can run until its entire charge gets discharged.

After complete discharging, connect the battery to a power source and charge it again. The owner can repeat this process an ample number of times.

However, a regular car battery can only discharge by about 1-3% each time. The battery then gets charged by the car’s alternator.

It’s worth noting that no car battery can lose more than 20% of its charge during its shelf life. Hence, regular charging of the car battery can damage it in the long run.

4. Cold cramping amps (CCA)

CCA is a unit that measures how much amps/current a battery produces at 0-degree Celsius for about thirty seconds.

As a car battery requires a sharp burst of power to get the car engine started quickly, it has a higher cold cramping amps value.

On the contrary, a marine battery has half the CCA value of an available car battery as it doesn’t need to deliver short and sharp power bursts. So, considering the CCA parameter, both batteries are non-interchangeable.

5. Price

It is another prime governing factor in this case. A marine or a deep cycle battery costs much more than a general car battery.

It goes on the lines that a deep cycle battery is to withstand a boat’s vibrations and deliver the same amount of power under all circumstances.

It isn’t the case with a car battery. So, using a marine battery will add up to the costs of the car’s overall maintenance.

6. Impact on the car’s electrical parts

This point is a bit different from the previous ones and is vital for discussion.

Since the car makers design every car keeping in mind a car battery as the sole operating battery, using a marine one instead may hamper the car to a great extent.

It involves damage and lessening the lifespan of the car’s electrical parts too. Or in another case, such practice may lessen the lifespan of the marine battery too.

So, it’s not advisable to use a deep cycle battery in a car. If you wish to do so, make sure the deep cycle battery:

  • It is at least 12V and gets charged up by the car’s alternator;
  • Meets the recommended CCA ratings of 650-800 CCA;
  • The battery size matches the original car battery’s size;
  • It has suitable terminal positions.

If any deep cycle battery fulfills the above parameters, it can only find usage in place of a car battery.


Though you may feel promoted towards a deep cycle battery for use in place of a car battery, it’s not the right decision you may make.

With different working powers and styles, you may overlook the possible damages it might cause to your car in the long run.

Anyway, even if you do, be sure you go after a superior marine battery with the above-listed specifications.