Lithium and AGM batteries are the top contenders in the battery industry, suitable for several applications today. However, lithium versus AGM, which is better? The simple truth is that lithium-ion batteries are better and can replace AGM batteries. This article covers a detailed overview of both battery types and how best they function.
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Lithium vs. AGM Batteries: What Are They
Lithium Batteries
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Lithium batteries are composed of many cells with a nominal voltage of 3.2V. It’s a type of battery predominantly used in electric vehicles and portable consumer electronics because it is rechargeable and reverses lithium ions reduction for energy storage. Types of this battery include;
- Lithium Iron Phosphate
- Lithium Manganese Oxide
- Lithium Cobalt Oxide
- Lithium Titanate
- Lithium Nickel Cobalt Aluminum Oxide
- Lithium Nickel Manganese Cobalt Oxide
Lithium Batteries Pros & Cons
Lithium-ion batteries stand out from other battery chemistry because of their high energy density and low cost per cycle. As with different battery types, lithium batteries have their unique advantages and disadvantages, which are listed below;
| Lithium Battery Pros | Lithium Battery Cons |
|---|---|
| Charges faster than other battery types | Sensitive to high temperature |
| No memory effect and therefore doesn’t need to completely discharge before recharging | Costly than other battery types |
| Handles many charge/discharge cycles | Can burst into flames when the “separator” is faulty |
| Has low DOD up to 95% | It’s hard to find or replace |
AGM Batteries
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Absorbent Glass Mat (AGM) battery technology uses the principle of lead-acid batteries, the newest type of lead-acid battery. They comprise two plates (positive and negative) that contain an acid-absorbent glass mat.
AGM batteries are designed to withstand various temperatures and perform better in hotter climates. The two types are; Thin Plate Pure Lead and Lead-calcium.
AGM Batteries Pros & Cons
AGM batteries utilize a glass mat rather than a liquid electrode to separate the plates. This gives them excellent storage capacity and makes them a little more responsive to overcharging than wet battery cells. Looking into their unique advantages and disadvantages, we have them stated below;
| AGM Battery Pros | AGM Battery Cons |
|---|---|
| No monthly maintenance required | Shorter lifespan than lithium battery |
| Do not require ventilation separators | Depth of discharge is about 50% |
| Fast recharging time | Produces poisonous gases like hydrogen that can lead to explosion |
| Less expensive than lithium |
Lithium vs. AGM Batteries: What’s Their Difference?
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Lithium Ah vs. AGM Ah
A lithium 100Ah battery is rated at 12.8V and lasts longer, from 120 hours to 36 minutes, than an AGM 100Ah battery. Typically, batteries with shorter charging times tend to be more efficient because they have fewer electrical losses. The shorter the charge cycle of a battery, the better the utilization of the current used to charge it. Lithium batteries charge faster than AGM and have higher efficiency, making the former better.
Lithium Battery Weight vs. AGM
Lithium batteries weigh less because of the absence of liquid acid, about one-third compared to AGM batteries, and they’re mostly smaller in size. In contrast, AGM batteries weigh heavier because of the presence of liquid acid. For instance, a 165Ah AGM battery weighs 53.6kg, while a 100Ah lithium battery with more power usage weighs 12.8kg. Therefore, lithium batteries are a better choice than AGM batteries.
Lithium Battery Size vs. AGM
An equivalent lithium battery of the same usage capacity will take up to half the physical space of an AGM battery, and you’re likely to get double power for the same area. For instance, a 100Ah lithium battery with a 100Ah usage can have a size of 321x152x197mm, while a 100Ah AGM battery having a 50A usage can have a size of 260x186x215mm.
Lithium Battery Lifespan vs. AGM
Lithium battery technology is known for its super durability, degrading capacity by less than 1% yearly, and providing about a 10,000 charge cycle life. In contrast, AGM batteries degrade quickly and provide a lifespan of about 500 charge/discharge cycles. However, lithium batteries have a longer lifespan, about six times more than AGM batteries.
Lithium Battery Depth of Discharge vs. AGM
The depth of discharge of modern lithium batteries is 98%, which means they can completely discharge without getting damaged, providing optimal conditions for use with available storage power. On the other hand, AGM batteries have a low depth of discharge of about 80% when new and 50% when old, making them less competitive. Since lithium-ion batteries have the highest depth of discharge and last longer, they are preferable to AGM batteries.
Lithium Battery Energy Density vs. AGM
Lithium batteries have one of the highest energy densities in the industry. Theoretically, the energy density is about 5000–11 000 Wh/kg which depends on the nature of the electrolyte and product reactions. In contrast, AGM batteries have a lower energy density of 25-30 Wh/kg. Therefore, when considering lithium batteries are 500% better than AGM batteries.
Lithium Battery Cost vs. AGM
Lithium-ion batteries perform better than AGM batteries when considering other parameters. However, they require a higher upfront, and their initial cost per kWh is much higher than that of the AGM batteries. Therefore, for initial cost, AGM batteries are better, but for lifetime cost, lithium batteries are the best choice.
Lithium Battery Warranty vs. AGM
Extended warranties endorse the longer lifespan of a product. Lithium batteries offer three years or more guarantees, and some products/brands provide more, like 6 years. On the other hand, AGM batteries have a shorter lifespan than lithium batteries which cover about 1-2 years. Therefore, lithium batteries are better sourced than AGM batteries.
Lithium Battery Maintenance vs. AGM
Although AGM batteries are a type of lead-acid battery, they do not require regular maintenance because the design is sealed. However, a misuse of the battery may require regular maintenance. In contrast, lithium-ion rechargeable batteries require low maintenance because there’s no memory and no scheduled cycling needed to extend the battery life. Lithium batteries are best because of their maintenance-free experience.
Lithium Battery Safety vs. AGM
Lithium battery does not produce gases and no toxic liquid. And they can be used without additional safety precautions needed. In contrast, AGM batteries produce gases such as hydrogen and, without adequate ventilation, can ignite and set the battery ablaze. Also, these gases are poisonous. For safety purposes, lithium batteries should be your choice.
Lithium-ion vs. AGM Battery Applications
Having considered the performance of lithium-ion and AGM batteries using various parameters, let’s further compare their specific applications. This will help you in making a good choice out of both batteries. The applications to be considered here are car, leisure, motorcycle, trolling motor, marine, etc.
Lithium vs. AGM Motorcycle Battery
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Generally, all batteries degrade with time. The process of recharging the battery to power your motorcycle engine, and then recharging it completes one cycle. And since lithium-ion batteries have a longer lifespan cycle of at least 2000 to 3000 charging cycles (if properly cared for), they tend to deliver more times the cycles than AGM batteries with shorter lifespans (1000 cycles). This makes lithium battery a better choice due to its longer lifespan.
Lithium Car Battery vs. AGM
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Electronic features like GPS, audio systems, heated seats, DVD players, etc., all demand battery. AGM batteries are great for high-end and advanced fuel-efficient vehicles that demand more extensive power. However, considering other features like the amp, lithium-ion batteries have a higher cranking amp than AGM batteries, like two or three more. This automatically translates to easier engine starts and less drain on the starter, no matter the temperature – very cold outside or very hot.
Lithium vs AGM Leisure Battery
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Lithium Iron Phosphate (LFP) battery is a perfect fit when considering a leisure battery for caravans or motorhomes. They are lightweight and much more compatible than AGM batteries, and as such, they can be installed anywhere in a campervan without much worry about weight distribution and storage.
In addition, LFP batteries have a long-lasting lifespan and low maintenance level than AGM batteries, making them the best for this application.
Lithium vs. AGM Deep Cycle Battery
A lithium deep cycle battery has a 2000 cycle at 100% DoD while an AGM deep cycle battery has a 300 cycle at 100% DoD. The greater the cycle life, the extra the upfront cost per kWh of lithium-ion batteries because they last longer than AGM batteries. Therefore, an AGM battery must be replaced 6 times before a lithium-ion battery will be replaced once.
Lithium vs. AGM Marine Batteries
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Absorbed Glass Mat (AGM) batteries are durable and last longer, making them suitable for marine batteries. However, lithium-ion batteries are the best marine batteries because they are sealed, meaning water splash or moisture cannot damage them.
In addition, most lithium batteries consist of an internal battery management system (BMS), which can detect unfavorable conditions and shut down to prevent the battery from damaging or thermal runaway. This makes lithium batteries the preferred marine battery over AGM batteries.
AGM Flooded Battery vs. Lithium
Although AGM batteries are a type of lead-acid battery, they aren’t flooded; instead, they contain glass mats that prevent spillage. Nevertheless, this battery type has a build-up of gases that can become toxic to the environment. In contrast, lithium batteries are sealed, have no liquid, and do not release gases, making them rate higher in preference than AGM batteries.
Lithium vs. AGM RV Batteries
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Lithium batteries are better accepted in the RV battery market than AGM batteries because they are lighter, more efficient, and more powerful than AGM batteries. Although costlier, they last longer and save more money in the long run. These parameters make them the best choice for most RVers.
Lithium vs. AGM for Trolling Motor
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Lithium batteries are chosen above AGM batteries for trolling motors because they maintain higher voltages for extended periods without any voltage drop. Additionally, they have potentially quicker charging cycles than AGM batteries and will not risk the battery’s life. The main downside for AGM batteries is that they could be more convenient and perfect for electric trolling motors.
AGM Battery vs. Lithium: In Summary
Finally, we’ve detailed the difference between AGM and lithium batteries using several parameters as a yardstick. And in many aspects, lithium batteries are superior to AGM batteries. However, your choice depends mainly on your battery requirements and expenditure.
