Anchor Travel is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Read more

Deep Cycle Vs. Car Battery for Trolling Motors: Why You Cannot Use Them Interchangeably?

Trolling motors are amazing for maneuvering and keeping the boat grounded in water. Despite facing tough competition from anchors for some time, they have come a long way in establishing their importance.

But what is it about them that makes them so important?

Deep Cycle Battery Vs Car Battery For Trolling Motors: Why You Cannot Use Them Interchangeably

Powered with electricity and with the ability to connect with relevant electronics, trolling motors are a great fishing accessory. They can use GPS location to stay in the same spot and connect with fish-finding electronics to simplify the process.

However, their entire operation is heavily influenced by one major factor; electricity.

All trolling motors need a good working battery to be able to work properly. Typically, trolling motors are used with deep cycle batteries because the basic design and dynamic fit the trolling motor need perfectly.

What happens if the deep cycle battery gets discharged? Can you use a simple car battery as a replacement for it?

This is a very common question and an even more common occurrence. Several people with a trolling motor have tried to temporarily replace their deep cycle battery with a car battery if they forgot to charge the former in time.

There is a lot to unpack here, but let’s begin with the basics.

Air up an inflatable boat using a foot pump and an electric pump

What is a Deep Cycle Battery?

Electric Trolling Motor Deep Cycle Battery
Click the image for more info

A deep cycle battery is designed to produce a consistent level of output over a period of time. They use their entire capacities for the purpose, discharging the battery significantly, and requiring full recharge to restart the cycle of performance.

Deep cycle batteries always come with a set number of cycles they can perform until they need to be replaced. There are also guidelines about when the battery needs to be recharged; for example, some brands ask customers to recharge at the point when no less than 20% battery remains.

Typical Usage

Deep cycle batteries are used extensively in our routine objects and electronics. The most common of these is the traffic signal which uses the battery to continue remaining operational over extended periods.

Other uses include the aforementioned usage in trolling motors, golf cart, floor scrubber, etc. they come in handy for several types of electronics.

What is a Car Battery?

AGM Battery: Absorbent Glass Mat Battery for Motorcycle
Click the image for more info

A car battery is designed to give a burst of energy to the electric-powered starting motor to get the engine started and the car moving. A car battery comes in two main types; standard wet cell batteries and absorbed glass mat batteries (AGM)

Car batteries tend to have a long life span, the plates wearing off with each cycle of recharge. Their average life span is two to five years, depending on usage, conditions, and maintenance.

Typical Usage

As implied by the name, car batteries are used in cars to provide them with the current they need to get the system started. There have been several unconventional usages for car batteries as well.

Several people use them to recharge their generators and similar electronic equipment. However, as great as this mechanism sounds, it shouldn’t always be applied.

The main discussion is the article will discuss the differences between deep cycle batteries and car batteries and why they should not be used interchangeably to power trolling motors.

Deep Cycle Battery vs Car Battery for Trolling Motors

The most important part of the discussion is exploring the differences between these two to understand which one is better for trolling motors; deep cycle batteries or car batteries.

Following are some of the main aspects which are both important for the needs of a trolling motor and where the two batteries tend to differ.

Energy output

Renogy Deep Cycle AGM Battery
Deep Cycle Battery – Click the image for more info

Deep cycle batteries tend to emit a consistent output of energy, powering the connected electronics for extended periods of time. They are designed to utilize a maximum part of their capacity before needing a recharge to restart the cycle.

In contrast, a car battery releases a burst of energy to charge the connected electronics and then goes back to its state of rest until it is used again. A very small percentage of their capacity is utilized in the process and therefore, they do not need frequent recharging.

Recharge Needs

Both battery types have different types of cycles and durability depending on their main framework. Deep cycle batteries are usually used until 80% of their capacities before they are recharged again.

In contrast, car batteries do not use a significant amount of their capacities during each performance, therefore, do not need to be charged right after it.

Cycle

Deep Cycle Rechargeable Battery for Trolling Motor
Click the image for more info

Since deep cycle batteries are meant to provide consistent and stable charges, their composition is also different. They have thicker battery plates and denser active material to help them perform the role more accurately. This feature gives them higher durability.

Car batteries tend to have thinner lead grids to complement their function of providing a high charge in a short time. This makes them less durable in cases where they need to be charged regularly.

Rating

Deep cycle batteries are usually 12 Volts and Ampere Hour Rating. Their specifications include the minimum amount of reserve capacity within them in addition to the estimated cycles it will complete during its lifetime.

Car batteries are often rated in Cold Cranks (CCA). Its common voltage lies between 12.4 – 12.9 Volts and your car system can indicate a problem if the numbers do not match.

Why You Should Not Use Them Interchangeably

Using car battery interchangeably

Now that we have explored the key differences between the two, there are several reasons why deep cycle batteries and car batteries should not be used interchangeably.

When you are cruising through the water, you will not need a burst of energy at the start and continue moving with the help of that. The key to getting the right performance is using the product which provides energy and electricity consistently throughout the experience.

Furthermore, this consistent need for output is also more compatible with a sturdier battery type that is at less of a risk of deterioration due to the frequency of recharge cycles.

Damage Potential

Trying the two batteries interchangeably can result in irreparable damage to your equipment as well as your batteries. Over usage of car batteries in trolling motors will damage them and reduce their lifespan.

Similarly, a deep cycle battery is not suitable for recharging cars because it never kicks off an extremely energetic current needed to get all the electrolytes to start working again.

Interstate Batteries AGM Deep Cycle Battery
Click the image for more info

Verdict

The verdict for this discussion is purely simple. Let’s briefly revisit the features before making the final call in the matter.

S. No.

Features

Deep Cycle Battery

Car Battery

1

Energy Output

Consistent, spread out over long periods, moderate.

Creates a surge of energy in the beginning to power other parts.

2

CapacityDeep Cycle is designed to complete one charge cycle each time, getting recharged after 80% usage.Car batteries do not have extensive capacities like deep cycle batteries. They are not suitable for usage for higher capacity.

3

Recharge needsSince the deep cycle has a ‘use until 20% of the charge is present, it needs to be recharged at the end of the day to restart the cycle.Car batteries do not utilize their full capacity after every usage which makes it unnecessary to recharge them frequently.

4

RatingUses ampere-hour rating.Uses Col Cranks (CCA) rating.

The only feasible solution is to choose to work with only deep cycle batteries for trolling motors as they are the most compatible with the equipment design.

It is better to keep car batteries for cars or other electronics that need a burst of electricity initially to work rather than a consistent stream of it.

Conclusion

To sum up, deep cycle batteries are the right option to choose for trolling motors. Their consistent format works with the consistent energy needed by trolling motors to maintain operations smoothly.

The car battery may just get you stranded in the middle of the water and it would not be a great sight getting back from there on your own.

Both sets of batteries have their own sets of usages and should not be used interchangeably. In case you ever have any doubt, always consider contacting a specialist to answer your queries.

Expert advice is likely to save you a ton of time and money, and reduce your stress, and wasted effort.

If you want to buy a good trolling motor, check out our review for the Minn Kota Ulterra Trolling Motor here. It will help you make an informed choice.


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.