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Starting Battery vs Deep Cycle Marine Battery

Starting Battery vs Deep Cycle Marine Battery. The plates on marine batteries are thicker and the structure is more robust so that the batteries can survive the vibration and pounding that can occur onboard any powerboat. Marine batteries were developed expressly for use on boats.

Due to the fact that top rated deep cycle marine batteries are often more expensive than automotive batteries, some people who own boats may be tempted to buy an automobile battery instead of a marine battery. Avoid making that bad choice at all costs.

When used in a boat, a marine battery will have a longer lifespan and will be more dependable than a standard car battery.

Starting Battery vs Deep Cycle Marine Battery
Starting Battery vs Deep Cycle Marine Battery


There are three primary categories of marine batteries, which are as follows:

1. Marine Cranking Batteries

They are designed to start the engine and may be rapidly recharged by the engine alternator. These batteries offer brief yet powerful bursts of energy over short periods of time and are intended to be used on boats.

It is not recommended to use a starter battery for trolling motors or anything else that requires electricity.

2. Marine Deep Cycle Batteries

They are engineered to undergo many hundred cycles of charging and discharging, in addition to being intended to discharge at a low rate over an extended length of time. An electric trolling motor and other battery-driven accessories, such as audio systems, a windlass, depth finders, fish locators, and applicances, should be powered by a deep cycle battery.

This type of battery is the optimal choice for this purpose. It is not recommended to use deep cycle batteries as a replacement for beginning batteries.

3. Marine Dual-Purpose Batteries

They combine the power of a starting battery with that of a deep cycle battery, making them an excellent option for spaces that are too tiny to accommodate two separate batteries. Although they are capable of performing the functions of both a starting battery and a deep cycle battery, the efficiency with which they do so is lower than that of separate batteries.

Deep Cycle vs. Cranking

If you have an electric trolling motor, thruster, windlass, or any other battery-powered equipment that demand significant quantities of electricity, you will want to purchase a second deep cycle “house” battery for the purpose of powering such devices.

A deep cycle battery should only be utilized in situations where there will be frequent cycles of high rates of discharge and recharging. When compared to a cranking battery, a deep cycle battery has plates that are both thicker and heavier and is designed in a different way.

The longer and higher amperage demands of equipment like trolling motors and windlasses, for example, would cause the thinner plates of an ordinary cranking battery to overheat and distort.

The cranking battery contains more plates, but they are thinner, so it can deliver a rapid jump in voltage to start an engine. However, it is not designed to keep a high power output for extended periods of time.

Although it is true that a deep cycle battery may be used to start your motor in an emergency, it is strongly advised that you utilize a system with two or even three batteries in order to keep the engine battery isolated from the auxiliary (home) batteries.

Having your battery “load tested” is the most reliable technique to determine whether or not it is still in excellent condition. The majority of auto parts stores and companies that specialize in selling batteries will do a free load test on your battery and let you know if it is still usable.

It is not necessarily the case that something is useless just because it has failed once or twice in the past. It’s possible that the issue isn’t with the battery in and of itself, but rather with the rest of your electrical and charging systems. If this is the case, you’ll need to pay attention to both of those.

Changing out the battery on your boat

When you need to replace a marine battery, it is important to get advice from the owner’s handbook of your boat or from a marine dealer, and you should also be sure to choose a new battery that is compatible with your vessel. The ampere hour rating, marine cranking amps, and reverse capacity are the three metrics that are used to evaluate marine batteries.

When looking for a deep cycle battery, the ampere-hour rating and reserve capacity are the two aspects that you should focus on paying the most attention to. When it comes to starting batteries, the marine cranking amps should be your first concern.

When looking for a battery that can serve two purposes, it is important to consider all three rankings.

You may need to upgrade to a battery with a higher amp-hour rating if you add electrical accessories to your boat. This is especially true if you spend a lot of time trolling with the engine at a very low speed (which results in less charging power from the alternator), or if you spend a lot of time beached or at anchor while using accessories such as the audio system.

Putting a Marine Battery on Charge

The vast majority of us are aware that whether we are purchasing a new or old boat, the batteries that come with it might not always be of the highest quality. If they appear to be accomplishing what they are supposed to, we don’t give them much thought.

However, every day heat is a big foe of batteries, and it may significantly cut down on the amount of time they are useful in environments that are warmer. The way in which the battery is cared for while the boat is stored away for the winter in regions of the nation that need us to do so is also essential to enhancing the battery’s expected lifespan during this time.

It is recommended that batteries be kept on a controlled charger that uses a “trickle” charging method while they are not being used. It is possible for a battery that has not been charged (and that is not maintained charged) to freeze in freezing conditions, which would likely cause the casing to fracture.

A battery is similar to many other things in life: if you don’t utilize it, you’ll lose it! Because of how frequently a car is driven and how frequently the battery is charged, a car battery will normally live far longer than a boat battery.

When it comes to boats, the age-old proverb that a battery has a life expectancy of two years is quite close to being accurate. When it is about to give out on you, it will often give you a heads-up in the form of a warning in the form of a “dead” battery one morning or a bit slower cranking speed than you are accustomed to.

After magically regaining life after being connected to the charger, the battery is now ready to accompany you on your journey. You might be under the impression that a light was left on or that the radio memory drew down the voltage.

It’s possible that the battery is sulfating, the plates are bent, and it can’t accept or keep a charge as well as it used to be able to.

How to keep out of battery trouble

Protect the marine battery by placing it in a sturdy battery tray. A good battery tray will have a base that is either screwed or fastened to the boat, as well as either a robust bracket or a locking strap that will secure it to the base.

You don’t want the battery to be jostled around while the sea is choppy.

  • Check the connections between the battery terminals on a regular basis to ensure that they are secure and free of corrosion. Nylon locking nuts are far more secure than the wing nuts that are often found on marine batteries. You should replace the wing nuts with these nylon locking nuts.
  • If you don’t take the boat out very often, you should choose a battery charger that has a maintenance mode so that the battery stays completely charged in between uses.
  • Before putting the batteries away for the off-season, make sure they are fully charged and then disconnect the connections so that nothing may drain the battery. If there is access to power at your off-season storage location, you should leave your batteries connected to a battery maintainer/charger during the off-season in order to ensure that they remain in good condition. If this is not possible, remove the batteries from the boat and put them somewhere that they can be charged regularly using a maintenance charger.
  • Even if the battery is contained within a box that is covered, you should still place a cover or “boot” over the top of the positive battery connection if the boat builder did not install one. If, for example, a tool were to be thrown on the terminal, the boot would prevent sparks and arcing, as well as the possibility of an explosion.