Batteries power everyday lives and most people only think about them when they don't work. While all batteries store energy, there are significant variations in how that works for different battery types and which are most effective for different applications. For instance, how do batteries in TV remotes differ from those powering golf carts? 

Before diving into deep cycle batteries, it's important to understand several basics of what a cycle is, what the depth of discharge implies, and what it means to deep discharge a battery. A single complete cycle is considered a full discharge and battery recharge. Discharge is measured by the capacity removed from a battery; the depth of discharge (DoD) shows how much battery capacity has been used during one discharge.

A complete discharge is 100% DoD which is inversely related to the state of charge (SoC), which is the amount of charge remaining in the battery (0% SoC). Armed with the understanding of a battery's cycle and DoD, you may wonder what classifies a deep discharge. A deep discharge is classified as 80% to 100% of the capacity discharge from the battery.

What are Deep Cycle Batteries?

Deep cycle batteries may appear similar to car batteries for individuals who aren't familiar with them. However, in reality, they're different. A deep cycle battery is a lead battery specially designed to produce sustainable power over an extended period and run reliably and efficiently until 80% discharged or more. 

At this point, you'll need to recharge the battery. It's crucial to note that although you can discharge deep cycle batteries up to 80%, most manufacturers recommend not discharging below 45% to increase the battery's longevity. So, the discharge level is the deep cycle and is different from other battery types that only produce short energy bursts before you need to recharge them. Specifically, a starter battery only discharges a small percentage- usually two to five percent every time it's used. 

When to Use a Deep Cycle Battery

As previously stated, deep-cycle batteries produce sustained energy, which makes them perfect for specific applications that need more than a simple start. The most common uses for deep-cycle batteries include the following:

• Recreational vehicles
• Marine applications
• Golf carts
• Materials handling such as forklifts
• Off-grid renewable energy
• Electric scooters
• Trolling motors on boats
• Electric wheelchairs

For certain applications, especially marine uses, hybrid batteries are another option. A hybrid marine battery can provide sustained power, and starter burst for marine applications but normally has a shorter lifespan than a dedicated battery. 

Benefits of Deep Cycle Batteries

Deep cycle batteries have some unique characteristics offering certain benefits for different applications. These features originate from the build of the battery itself and ensure it fulfills the use requirements. Below are the main benefits of deep-cycle batteries. 

Longer Life & Higher Capacity

The main benefit of a deep-cycle battery is its ability to produce steady power over a longer duration. This is mainly achieved via thicker plates in the battery construction, which reduces the surface area. 

More Power

Deep cycle batteries also have a high-density active material that increases capacity. For instance, a lead acid battery can give 200 cycles based on 100% DoD to 80% capacity. In contrast, a deep cycle battery can attain over ten times the amount at 2000+ cycles. 

Improved Safety

 AGM batteries use an electrolyte absorbed in glass matt, and Gel batteries use a gelled electrolyte. If used and discharged correctly, these batteries won't release any gasses. However, if they overpressure, the safety valve opens and releases the gas buildup. As a result, deep cycle batteries don't have to stay upright, and they automatically eliminate any spillage, cutting down on the corrosion issues common with the flooded types. 

Lower Maintenance

When not in operation, you should always fully charge your deep-cycle battery. Deep cycle batteries are always built with longevity in mind and don't tend to lose a lot of charges when sitting idle. As a result, charging them fully before you store them and checking them frequently to top them off in case they discharge to 20% DoD will permit you to keep them in good shape.

Besides, you won't have to constantly keep your charger plugged in, which makes them easy to maintain. Remember to keep your deep cycle batteries in a store, in a cool, dry place, to prevent damage. 

Types of Deep Cycle Batteries 

Even among the deep cycle batteries with similar functionality, there are various types. The most common types of deep-cycle batteries include the following:

Gel Cells

Gel Cell battery is another Valve regulated Lead Acid battery made with a gelled electrolyte, the usual sulfuric acid and water mix suspended in silica gel. They're more expensive than flooded lead acid batteries and require a special charger and regulator. A good example of a gel cell battery is the Renogy 12V/200AH Hybrid Gel Deep Cycle Battery. 

AGM 

Absorbent Glass Mat Deep cycle batteries are one of the VRLA types where the AGM refers to the thin fiberglass mat used. The mats are placed between the lead plates to absorb the electrolyte to prevent leakage and unwarranted electrolyte movement. The mats also act as a damper between the lead plates, which makes the battery resistant to shock and vibrations, as well as giving the battery the ability to handle low temperatures.

AGM batteries such as the Vmaxtanks MR127-100 12V/100AH High-Performance AGM Deep Cycle battery are more expensive than the flooded batteries and are typically maintenance-free and positioning non-sensitive. They're fast charging but sensitive to overcharging, requiring a regulated charger. 

Lithium Ion (LiFePO4)

The lithium Ion deep cycle batteries are new and 30% lighter than flooded batteries. Moreover, they have 90 to 100% usable capacity, come with a fast recharge rate, and can last up to 5000 charge cycles. A perfect example is the CHINS 12.8V/400AH Lifepo4 Deep Cycle Battery with over 2000 cycles. 

Lithium-Ion batteries usually provide a constant voltage as it discharges, meaning that if you're using one to light up a room, the lights will stay bright even as the battery discharges. The lights will eventually go off once the power is completely out and will not dim slowly as the battery goes down. 

Lithium-Ion batteries normally use the deep cycle common function. They are popularly used in power backup systems or for solar energy storage. While they're maintenance-free, lithium-Ion batteries will require a battery maintenance system. 

Lead Acid Battery

The flooded lead acid battery is the oldest type of car battery in use. The lead plates are usually submerged in an electrolyte mix of water and sulfuric acid. The chemical reaction during discharging and charging releases gasses vented from the battery. This produces a dip in the electrolyte level, which you must top up frequently. The usable capacity of a lead acid battery is around 30-50%, with the charging happening in stages to leave room for overcharging or undercharging. Generally, the average charging efficiency is approximately 70-85%.

Selecting the Right Deep Cycle Battery 

Selecting the right deep-cycle battery is crucial, depending on the operating and application conditions. Below are some helpful tips for selecting the right deep-cycle battery. 

Capacity & Voltage

Deep cycle batteries also have a high-density active material that increases capacity. For instance, a lead acid battery can give 200 cycles based on 100% DoD to 80% capacity. In contrast, a deep cycle battery can attain over ten times the amount at 2000+ cycles. 

Size and Weight 

Size and weight are essential factors to consider if you plan on using your deep cycle battery on an RV or a watercraft, where you'll have to run various electronic applications for a long time. A lithium-ion deep cycle battery is energy-dense and lightweight compared to lead-acid batteries. A smaller, lighter battery will give you more flexibility when considering your application's balance and total weight. 

Maintenance and Care 

One of the main benefits of lithium-ion deep-cycle batteries is their long and low-maintenance lifespan. You don't need to refill a quality lithium-ion battery when you store them. You can store it for an extended period and return it with minimal maintenance. 

Charging 

Lithium-ion deep-cycle batteries usually charge faster than lead-acid batteries. For applications where the charging time is crucial for use, such as marine power, all-terrain vehicles, and other recreational uses, it's essential to charge and get going as fast as possible. With lithium, you can charge two to three times more quickly than lead-acid. 

Moreover, lithium batteries charge to full in a single session, making the charging process seamless. On the contrary, you must charge lead-acid ones over several sessions to reach full capacity, which requires active maintenance.

Storage 

Deep cycle batteries require minimal storage requirements and don't tend to lose a lot of charge when sitting idle. As a result, charging them fully before you store them and checking them frequently to top them off in case they discharge to 20% DoD will permit you to keep them in good shape.  

Disposal 

It's important to follow the guidelines of the local trash disposal facility and avoid disposing of your deep cycle battery in trash bins. Instead, place masking, electrical, or clear tape on batteries that are nine volts or more. You can count on most deep-cycle batteries to follow all the environmental regulations making them safe for disposal. 

Final Thoughts

Deep cycle batteries are ideal for their longevity, high capacity, improved safety, and lower maintenance than other battery types. They're perfect for use in marine applications, golf carts, forklifts, recreational vehicles, off-grid renewable energy, and other applications that need more than a simple start. 

To learn more about deep cycle batteries, browse our collection of Deep Cycle Batteries to find the one that suits your needs. If you have questions or concerns, please don't hesitate to contact our Customer Support team.