In order to make good environmental and performance promises, battery manufacturers are moving away from conventional lead-acid batteries. Today, you can avail of AGM or lithium-ion batteries for any vehicle, offering substantial upgrades at reasonable prices. There are even variants, such as Tesla electric cars, that only work for a single type of battery.
Still, a few people who can buy hybrids or upgrade from their factory-fitted batteries might need clarification with the available choices. Going for the wrong version not only bleeds money over time but can also lead to an unprecedented disaster if you’re careful. If you’re one of those people, then this guide will let you compare AGM vs lithium batteries in detail.
How Do the Technology of AGM vs Lithium-Ion Batteries Differ?
Both AGM and lithium-ion batteries are a massive upgrade on flooded lead-acid batteries. Although, the way they tackle the issues has various notable distinctions.
Absorbed Glass Mat (AGM) batteries utilize the same chemical reactions as a run-of-the-mill lead-acid battery. The electrolyte contains the necessary ions dissolved for creating the necessary reactions at both electrodes. Still, there are structural differences that affect the performance and lifespan of the battery.
In the case of AGM, each cell is separated within its own compartment. So, they don’t share direct electrolyte contact, making it more convenient to isolate damaged cells in the event of an accident. Moreover, the more robust seals and insulated terminal holders make it less likely that the electrolyte may evaporate into the air.
Sometimes, to build something truly better, you have to tear it down and start from scratch. That’s what lithium-ion batteries are all about. They use lithium-metal phosphate as a solid electrolyte at room temperature. That alleviates the issue of degradation.
Furthermore, it’s highly tolerant of extreme variations in temperature. Combined with electrodes made from lithium and metal hydrides, the battery can store plenty of electrical energy within a confined space.
How Do Lithium Batteries vs AGM Batteries Compare?
Now that you know the basics of AGM and lithium batteries, let’s look at various criteria and observe how the two compare head-to-head.
Depth of Discharge (DoD)
Every time you use a battery, it causes some damage as the ions in the electrolyte, and the electrodes are consumed. The depth of discharge measures the electrical energy that can be safely discharged from the battery without causing too much harm.
While AGM batteries have more DoD than conventional lead-acid batteries (80%), they are no match for lithium-ion batteries (98%). The latter have high thermal stability, allowing them to supply current consistently without degrading the internal components. It’s also more convenient to revive completely drained lithium batteries than AGM variants of similar output.
Lithium-ion batteries can last well over 20 years, provided you don’t damage them or conduct continuous charge/recharge cycles. A typical version is rated for over 10,000 charging cycles, with an annual degradation rate of less than 1%.
In contrast, AGM batteries usually contain a 5-year warranty. Although, people have stated that they have maintained their AGM batteries for more than ten years. Most of them offer around 500 charging cycles. So, lithium batteries are the ideal choice if you’re looking for long-lasting batteries.
Size and Weight
Your vehicle’s battery should fit the specifications without affecting the weight too much. That’s why lithium-ion batteries are more adept for any application. They are lightweight and can be built around any physical shape.
That’s not possible with AGM batteries that only have a rigid structure. Any deviation from the design may result in losing the integrity of the battery case.
Embodied Energy (Energy Density)
Embodied energy is the cumulative energy required to manufacture a battery of given specifications. That affects the consumption of resources and CO2 emissions, which is why choosing one with more embodied energy makes your purchase more eco-friendly.
A lithium battery has about five times the embodied energy of an AGM battery since it uses solid electrolytes and a lighter casing that doesn’t need to be isolated.
Charge Time and Efficiency
If you observe most of the electronic equipment you use today, you’ll notice that almost all of them have lithium-ion batteries. That’s because those devices need a fast charging time while also capable of continuous discharge.
That’s why lithium-ion batteries are the better choice if you want to improve charge times. On average, they can charge four times as fast as conventional lead-acid batteries while offering the same electrical energy as bulkier AMG variants.
Due to the rare earth elements involved in their manufacturing, lithium batteries are more expensive to purchase. If you’re custom ordering them, be prepared to pay upwards of $1000 for a 12V version, including shipping. In comparison, AGM batteries are less expensive, and you can find them at your nearest Walmart or Target store. If you nail the perfect discounts, a 12V variant can cost less than $150.
While AGM batteries are meant to be rugged, you still need to check the condition every few months. Nevertheless, any cracks or damages can be quickly repaired at any local service station. In contrast, lithium batteries are more toward the fit-and-forget end. You won’t encounter an issue for years, but if you do, it can cost about half its original price to restore the battery to its factory performance.
Given that lithium batteries last far longer than AGM batteries, you’ll most likely obtain a more comprehensive and extended warranty. Yet, you won’t find many companies offering replacement warranties on Li-ion batteries, which is somewhat of a standard with AGMs.
Both AGM and lithium batteries are pretty adept at absorbing high-speed impacts and vibrations. However, AGMs can cause the build-up of hazardous gasses like hydrogen. If left unchecked, those can cause a massive fire when the battery is overloaded. That’s not a problem with lithium-ion batteries, with most manufacturers equipping them with a fire suppression system, making them less likely to light up.
Application Comparison of AGM vs Lithium Batteries
Given the differences between AGM and lithium batteries, let’s examine which are most suitable for the various applications.
A UPS battery needs to provide high-energy density without too much downtime for charging. That’s why lithium-ion batteries are much more suitable for a UPS. Unlike AGM batteries, those can sustain the electrical requirements for longer without maintenance. It’s also less likely to catch fire in case of varying humidity and temperature conditions.
Electric Vehicle Battery
EVs need a light battery design that remains compatible with their weight scale and distribution without reducing the current capacity of the motors. So, lithium-ion batteries are best for the job. They also allow faster recharging cycles, meaning lower downtime when recharging en route.
Solar Energy Storage
Solar energy can be limited and uneven, depending on the geographics of an area. Thus, you need a battery that not only has high DoD but can provide uniform electricity for extended periods. A lithium battery ticks all of these boxes.
As the temperature decreases, it can decrease a battery’s performance to an inverse degree of the quality of insulation. That’s why AGM batteries are more suitable for this application than lithium batteries. Although you can avail of Li-ion variants with self-healing systems, those are often so expensive that it’s more economical getting 3 or 4 AGM batteries instead.
AGM or gel batteries are often unsuitable for marine applications since the level of liquid electrolyte changes with the vessel’s orientation. That’s why lithium batteries with a solid electrolyte provide a more suitable match.
Most people who own an RV or any other recreational vehicle need a deep-cycle battery with low maintenance and a high degree of safety. That’s why lithium-ion batteries are better suited for such applications. Their lightweight design aids the vehicle’s on-road performance, and the owners can place custom orders that perfectly fit their designs.
Which Battery to Choose?
Choosing the correct battery involves several factors. While the above criteria are clear-cut, it’s best to focus on the precise specifications and budget before selecting the appropriate variant. In addition, it doesn’t help to trust only online sources. You can check in with your local electrician or another specialist in the field to discuss your concerns.
FAQs (Frequently Asked Questions)
Is AGM Better Than a Lithium Battery?
An AGM battery can offer more cold resistance than most lithium batteries, but the latter is more advanced in all other crucial criteria.
Can I Replace an AGM Battery With a Lithium Battery?
Yes, if your vehicle supports the swap. It’s not a great idea to go with a Li-ion battery if the battery bay is too large or non-modifiable for the same voltage and current specs.
Can I Replace My Lead Acid Battery With a Lithium Battery?
Yes. Almost any conventional lead-acid battery has a lithium battery equivalent that is lighter and longer lasting.
Can You Charge an AGM Battery With a Lithium Ion Charger?
No. Most lithium-ion chargers are specifically designed to provide high current discharge, which can cause an electrical fire within an AGM battery.
Can You Charge a Lithium Battery With a Regular Battery Charger?
It depends on whether the charger is configurable enough. Lithium batteries require a high-density charging rate, which only a few standard battery chargers can provide.
Can I Charge My Lead-Acid Battery With a Lithium Charger?
No. The risk of overloads and fires is much greater, as the high-density current can evaporate the electrolyte quickly.
Are Car Batteries Lithium or AGM?
Since AGM batteries are cost-effective and last for more than a few years, most manufacturers ship their vehicles with AGM. However, you can swap them for Li-ion, provided you can customize the battery or the vehicle to fit the specifications.
And that’s all the differences you need to understand AGM vs lithium batteries. We hope this guide helps you decide on the best product for your needs. Remember, the more time and money you invest today, the less you have to worry long-term. So, be sure to check out a few other guides on our website before you make up your mind.