If you love the outdoors and are thinking about how you can get the same experience with electricity outdoors as you do at home, then a 12v deep cycle battery would be a great solution.

Whether for lighting, kitchen power, or everyday appliances in your RV, deep cycle batteries will make it much more convenient and comfortable to start outdoor or long road trips.

So what is a 12v deep cycle battery, and how do we understand it? If you want to know this, you have come to the right place.

This article will help you get a comprehensive answer from all aspects of deep cycle batteries. So if you are interested, read on!

Table of contents

1. What Is a 12V Deep Cycle Battery?

A 12v 100ah deep cycle battery is a rechargeable battery designed to provide a steady, continuous low current, it can be discharged to over 80% and recharged numerous times without causing damage to the battery itself.

What does a 12v Deep Cycle Battery Mean?

The term "deep cycle" refers to the discharge level, as deep cycle batteries can discharge to more than 80%, which is much higher than the typical discharge rate of starter batteries (usually 2%-5%).

Deep cycle batteries can provide low current energy consumption over a long period and are mainly used to meet our continuous current power needs, such as electrical power for RVs, off-grid backup power, etc.

Compared to starter batteries, which provide a short period of intense high current, 12V 100ah deep cycle batteries use thicker lead plates and more dense active materials. These facilitate repeated charging and discharging while effectively preventing corrosion due to extended charge cycles.

Types Of 12V Deep Cycle Batteries

Although the main functions of 12v 100ah deep cycle batteries are similar, there are different types. There are two types of deep-cycle batteries: lead-acid deep-cycle batteries and lithium-ion (Li-ion) deep-cycle batteries.

Lead-acid deep cycle batteries include sealed lead-acid batteries (SLA) and flooded lead-acid batteries (FLA). SLA is also known as VRLA batteries, which are short for valve-regulated lead-acid batteries. Among VRLA batteries, there are absorbed glass mat batteries (AGM) and gel batteries (GEL).

Lithium-ion (Li-ion) batteries are another type of deep cycle RV battery. It is a relatively new type of battery compared to lead-acid batteries. Commonly available are lithium cobalt oxide (ICR), lithium manganese oxide (IMR), lithium manganese nickel (INR), and lithium iron phosphate (LFP) batteries. Lithium iron phosphate batteries are known for providing better safety features among them.

Since there are so many 12v deep cycle batteries 100 ah, how do we choose? Don't worry. We'll go over the pros and cons of each battery below and help you understand them all.

Flooded Lead-Acid Batteries (FlA)

"Flooded" means that the pole plates of these batteries completely submerge in an electrolyte made from a mixture of sulfuric acid and water. It designs to ensure that the pole plates will not be damaged.

12v 100ah Flooded batteries are the oldest type of lead-acid batteries. It has reliable performance and is inexpensive. It has a charging efficiency of about 70-85% and a usable capacity of about 30-50%. Life spans are relatively short, usually only 4-8 years.

The most common problem with flooded deep cycle batteries is the loss of active material due to plate shedding and the corrosion of the internal grid supporting the active material. This problem is mainly because some water is broken down from the electrolyte during the charging process of a submerged deep cycle battery, resulting in gas. These gases are expelled from batteries, causing the electrolyte level to drop. Then the electrolyte level is lower than the top of the electrode plate.

So if we want to prolong the service life of flooded lead-acid batteries, we need to check the electrolyte level regularly and add water at the right time. In addition, we should make sure the lead-acid battery is always upright to avoid electrolyte leakage.

Absorbed Glass Mat batteries (AGM)

12v AGM batteries are a type of VRLA battery, so-called valve-regulated, which means that the battery has a tiny valve to maintain a slight positive pressure. An absorbent glass mat means electrolytes immerse in a glass mat between the electrode plates.

AGM battery deep cycle battery has a usable capacity of 60-80% and a self-discharge rate of about 1-3% per month. It has 80% depth of discharge (DoD), 95% charging efficiency, and charges much faster than flooded batteries. The life span is about six years.

The price of AGM batteries is higher than that of flooded batteries. If overcharged, it will reduce the life of 12v 100ah AGM batteries.

Gel Batteries (Gel)

The 12v gel battery is also a VRLA battery. The electrolyte in gel cells mix with an oxidized silica gel, and sulfuric acid and water suspend in the silica agent. So they are less susceptible to evaporation and less likely to require much maintenance.

Gel cells have a charging efficiency of about 85-90% and a lifetime of about ten years. They have a lower freezing point and a higher boiling point, making them suitable for use in extreme conditions.

Gel batteries are more expensive than lead-acid batteries and AGM batteries. 12v 100ah Gel batteries are also sensitive to overcharging, so it is best to stop charging when fully charged to avoid severe damage to the battery.

Lithium-Ion Battery

The 12v lithium-ion battery is the latest deep cycle battery. It has a high energy density, a self-discharge rate of only 1-2% per month, and a charging efficiency is 99%.

Its deep cycle times are as high as 3000 to 5000 times, and its service life is longer than other batteries, generally about ten years. However, they are currently more expensive due to the expensive raw materials used to make 12v 100ah lithium-ion batteries.

2. What Is a 12v Deep Cycle Battery Used For?

The major applications of 12v deep cycle batteries:

  • RV, Motorized wheelchairs, golf carts, electrically-propelled forklifts, emergency equipment, lighting, etc.
  • Marine uses. Sailboats lacking power generation capability, Trolling motors for recreational fishing boats.
  • Off-grid energy storage systems for solar power or wind power.

3. How Long Do 12v 100ah Deep Cycle Batteries Last?

The time the battery lasts depends on the power of the equipment you are using. To find how long the battery will last, we need to know the battery capacity.

Almost all deep cycle batteries have an output voltage of 12V, so the battery capacity is 100Ah × 12V = 1,200Wh. Dividing the battery capacity by the device power gives us an idea of how long the 12v 100ahbattery will last.

4. What Is The Best 100ah Deep Cycle Battery?

100Ah deep cycle battery specifications to consider:

  • Battery Performance.
  • Energy Density. Higher energy density also means lighter, smaller, and more flexible deep cycle batteries.
  • Charging time. We all want our batteries to charge faster to make it easier for us to use our devices again.
  • Shelf life and cycle life. Longer life means we don't often need to replace batteries and can reduce unit costs.
  • Base cost. The purchase cost of batteries, the cost of routine maintenance, and the budget you intend to spend on it.

5. Deep Cycle Battery FAQs

Is a Dual-Purpose Battery The Same As a 12v Deep Cycle Battery 100ah?

No.

Dual-use batteries, as the name implies, mean that these batteries can be both starter batteries and deep cycle batteries, a hybrid of the two.

But dual-purpose batteries are not as effective as a separate starter and deep cycle batteries in their respective usage scenarios. It endures multiple discharges and recharges between the two.

Is There a Difference Between a 12v Deep Cycle And a Marine Battery?

Yes.

A marine battery may be a starter battery, a deep cycle battery, or a dual-purpose battery. So not all marine batteries are deep cycle batteries.

Deep cycle batteries use for more than just marine applications, so not all 100ah deep cycle batteries are marine batteries either.

Can You Use a Regular Battery Charger On a 12v 100ah Deep Cycle Battery?

No.

Conventional battery chargers will charge quickly. Charging a deep-cycle battery with them will cause deep-cycle batteries to overheat and damage them. That's why 12v deep cycle batteries all need a special charger.

What Is The Best 12v 100ah Deep Cycle Battery Charger?

The three most important considerations:

  • Rated voltage. A battery charger should match the battery's rated voltage.
  • Amperage rating. The current rating of the charger directly affects the speed of battery charging. Generally speaking, the higher the A rating of the charger, the faster the battery will charge. But the amperage rating is not supposed to be higher than the battery's amp-hour rating, as this can damage your battery.
  • Supported Features. The most important features of a deep cycle battery charger are those related to maintenance. A deep cycle battery charger with maintenance-related features will ensure that you take some proper steps to care for your batteries.

What Amp Should I Charge My 100ah Deep Cycle Battery?

It depends on the ampere-hour capacity of the battery you are using. Generally speaking, charging time is shorter at higher amperage. But also keep in mind that a higher current is not always better. The excessive amp can damage the battery. The amperage should not exceed 25% of the battery's ampere-hour capacity.

When To Charge a 12v 100ah Deep Cycle Battery?

Most 12v deep cycle batteries can withstand discharge to 50%, so if you can charge them before they fall below 50%, the battery will last a little longer. It is generally best not to let the battery charge below 30%, which may shorten batteries' lifespan.

How Do I Know When My 12v Deep Cycle Battery 100ah Is Fully Charged?

The vast majority of deep cycle battery chargers have an indicator light that shows when the battery is fully charged. Once the light is on, it indicates fully charging.

How To Maintain 12v Deep Cycle Batteries?

Regular full-cycle equalization charge.

It is best to ensure that each charge is a full-cycle charge to prevent sulfation from damaging the plates. Charge regularly and charge promptly when the charge level falls below 50%. It is also best to use a dedicated charger for all deep cycle batteries.

Regular equalization charging will also extend the life of the battery. Equalization charging is a long, low-current charge of a deep-cycle battery after the normal charge cycle. Batteries frequently used can have equalization charging once a month.

Battery Cool Down Period.

After a battery has been used or charged for a while, it is best to give batteries some cooling time to avoid generating a lot of heat that can affect the battery's performance or cause it to fail.

Use batteries of the same size, age, and use level.

When connecting multiple batteries in series, parallel, or series/parallel, it is best to use batteries of the same size, age, and use level.

When To Charge a 100ah Deep Cycle Battery?

Most 12v 100ah deep cycle batteries can withstand discharge to 50%, so if you can charge them before they fall below 50%, the battery will last a little longer. It is generally best not to let the battery charge below 30%, which may shorten batteries' lifespan.