AGM vs. Lithium Batteries: Which is Better for RV and Marine

In today's world, where portable power is essential for a wide range of applications, the choice of battery technology can make a significant impact on performance, longevity, and overall cost. Two popular options that often come into comparison are AGM (Absorbent Glass Mat) batteries and lithium batteries.

Both have their unique characteristics and applications, making it crucial to understand the differences to make an informed decision.

What is AGM Battery

AGM stands for Absorbent Glass Mat, which refers to a type of lead-acid battery. AGM batteries are a modern and advanced version of the traditional lead-acid battery. In an AGM battery, the electrolyte (sulfuric acid) is absorbed into a fiberglass mat, which makes the battery spill-proof and maintenance-free.

These batteries are commonly used in applications where maintenance-free and reliable power storage is required, such as in backup power systems, renewable energy storage, marine and RV applications, and in certain automotive applications. AGM batteries are known for their ability to deliver high currents on demand and are often used in situations where a reliable power source is crucial.

What is Lithium Battery

A lithium battery is a type of rechargeable battery that utilizes lithium as an active material. These batteries are widely used in numerous applications due to their high energy density, relatively low self-discharge, and ability to be recharged hundreds to thousands of times. Lithium batteries come in various chemistries, including lithium-ion (Li-ion), lithium polymer (LiPo), lithium iron phosphate (LiFePO4), and others.

Lithium-ion batteries are commonly found in consumer electronics such as smartphones, laptops, and tablets, as well as in electric vehicles, power tools, and energy storage systems. They have become popular due to their lightweight design and high energy density, making them well-suited for portable electronic devices and electric vehicles.

Lithium batteries are known for their ability to deliver high power and energy density, making them a popular choice in many modern applications. However, it's important to note that lithium batteries require careful handling and charging to ensure safety and longevity.

The Comprehensive Comparison of AGM VS Lithium Battery

To comprehend the variance in performance between the two, we will assess them based on critical parameters. This evaluation will help determine which battery is superior for each parameter, enabling you to make an informed decision.

Depth of Discharge (DoD):

• AGM: Typically offers a depth of discharge around 50%. If deeper using, the battery would be damaged.
• Lithium: Provides a higher depth of discharge, over 80% and even 100% without damaging the battery. Consequently, this implies that a lithium battery of the same capacity offers twice the energy available compared to an AGM battery.

Lifespan:

• AGM: With life cycles around 300-500, the lifespan of AGM batteries can range from 3 to 5 years.
• Lithium: Lithium batteries often have a longer lifespan, for example LiTime lithium batteries have the life cycles 4000-15000, ranging from 10 to 15 years serving.

Size and Weight:

• AGM: AGM batteries are generally heavier compared to lithium batteries. A 12V 100Ah AGM battery weights around 63-70lbs.
• Lithium: Lithium batteries are known for their compact size and lighter weight. A LiTime 12V 100Ah Group 24 Lithium battery weights only 21 lbs.

Energy Density:

• AGM: A Group 24 AGM battery has an energy density of around 7.23Wh/lbs .
• Lithium: A Group 24 lithium batteries offer a higher energy density at 60.95Wh/lbs.

Charge Time and Efficiency:

• AGM: AGM batteries generally have longer charge times and lower charge efficiency compared to lithium batteries. It would take around 8 hours to fully charge the battery.
• Lithium: Lithium batteries can be charged more quickly and with higher efficiency compared to AGM batteries. Most lithium batteries supports 0.2C charging, for example, to charge a 12 volt 100Ah lithium battery, the recommended charging Amp is 20A, it would take 5-6 hours to fully charge. Some lithium batteries like LiTime lithium golf cart batteries, supports 1C charging, and it would take only 1-2 hours to fully charge.

LiTime 48V 30Ah Golf Cart Lithium Battery

Maintenance:

• AGM: AGM batteries typically require minimal maintenance, but may need occasional equalization charging and should be kept at full charge when not in use.
• Lithium: Lithium batteries require minimal maintenance and do not need regular equalization charging.

Environment Friendly:

Both AGM and lithium batteries are recyclable and offer environmentally friendly options, but lithium batteries have a slight advantage due to their higher energy density and longer lifespan, resulting in fewer batteries needing to be recycled over time.

Safety:

• AGM: AGM batteries are generally considered safe, but can release hydrogen gas if overcharged or improperly maintained.
• Lithium: Lithium-ion batteries do not generate gas accumulation and contain no toxic liquids, allowing for their use without additional safety precautions. Furthermore, lithium batteries are equipped with a BMS (battery management system) to provide protection.

Bluetooth Technology

Another significant advantage of lithium batteries lies in their technology. In contrast to AGM batteries, lithium batteries like LiTime Group 24 smart and GC2 golf cart battery incorporate Bluetooth technology. This feature enables you to monitor your battery's status at any given time, ensuring smooth operation before embarking on a boating trip, RV adventure, or UTV excursion.

Through Bluetooth connectivity, you can easily check your remaining charge, voltage levels, temperature, and more, empowering you with direct access to vital information. With lithium batteries and Bluetooth technology, bid farewell to guesswork and uncertainty, and welcome peace of mind as you remain in complete control of your power requirements. By accessing our LiTime App with your smartphone, Bluetooth facilitates effortless access to all your battery's information with just a few taps.

Initial Cost

Cost is a critical consideration when choosing between two battery types. Two cost factors to evaluate are the initial cost and the cost per kWh.

Lithium-ion batteries entail a higher initial investment. Despite their superior performance over AGM batteries across other parameters, the upfront cost is significantly greater.

AGM batteries emerge as the more cost-effective option in terms of the initial investment. However, when assessing the lifetime cost, lithium-ion batteries prove to be the superior choice due to their significantly longer lifespan.

Comparison of AGM and Lithium Battery Applications

Having assessed the performance of AGM and lithium batteries across various parameters, it's important to consider how well they suit specific applications.

Batteries are not universally applicable, and certain models may excel in specific scenarios. Let's explore the specific applications where AGM and lithium batteries are ideal:

Leisure Batteries

For leisure battery applications in motorhomes or caravans, LFP batteries are an ideal choice. In the RV battery market, users seek a product offering deep cycle life, high safety, and low maintenance. Lithium leisure batteries, particularly lithium iron phosphate batteries, excel in meeting these criteria. When using lithium batteries in a motorhome, dedicated battery chargers are recommended over built-in chargers.

Marine Batteries

Traditional liquid or gel batteries are not well-suited for marine applications due to the constant movement affecting the battery's surface level. However, since most lithium batteries contain no liquids, they are well-suited for marine use. What’s more, high quality marine lithium batteries like LiTime Trolling Motor Battery Series, have upgraded BMS designed for marine applications with moisture, dust, water and salt spray resistance for reliability in humid environments.

Freezing Conditions

Operating batteries in freezing conditions poses challenges, as battery charging can be problematic at low temperatures. This is an area where AGM batteries outperform lithium batteries.

Nevertheless, high-quality lithium batteries such as LiTime Lithium’s LFP batteries feature a self-heating function, enabling them to perform comparably to AGM batteries even in sub-zero conditions.

Solar Energy Storage

Due to their high energy density, depth of discharge, and extended warranty, lithium iron phosphate batteries are the optimal choice for solar energy storage. While the lower initial cost of a single AGM battery might be a consideration, when assessing lifetime cost, a single lithium battery can match the performance of 16 AGM batteries. Consequently, for solar storage applications, LFP batteries are the superior choice.

UPS Battery

Similar to the RV battery market, the UPS market favors LFP batteries. They offer superior safety, require no maintenance, and provide higher capacity compared to comparable AGM batteries, making them a more convenient long-term ownership option.

The Ultimate Decision

While both lithium and AGM batteries have their pros and cons, when seeking a dependable, efficient, and lightweight maintenance-free solution, the decision becomes evident. For your application, lithium batteries stand out as the top choice. Their enhanced performance, extended lifespan, and built-in Bluetooth technology offer significant ease and convenience. Moreover, they can ultimately save you valuable time and money.