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AGM vs. Lithium | Which battery is best for Van Life?

AGM vs Lithium-Ion Batteries

AGM vs Lithium Batteries. Which type of battery is best for your campervan electrical system? Yes, we’ve heard that lithium-ion batteries are the newer technology and are becoming increasingly more popular.

But surprisingly, the decision between AGM vs Lithium isn’t always as obvious a choice as it might seem.

In this post, we discuss the primary differences between AGM and Lithium batteries. Spoiler alert, one type of battery isn’t necessarily “better” than the other and depends entirely on your needs and situation.

Let’s get started!

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Table of Contents

AGM vs. Lithium Comparisons

To get a proper understanding of the primary differences of an AGM vs lithium battery it’s important to know basic technical details and battery jargon. But don’t fret, we’ll go slow and explain everything in simple terms.

1. Initial Cost

One of the glaring differences between AGM and Lithium batteries is the initial purchase cost. Currently, a lithium battery of the same capacity is 3-4x more expensive than a comparable AGM.

So if budget is a concern, AGM batteries may be more attractive for your needs.

Interesting note: Lithium batter prices have come down substantially in the last couple years and Chinese-branded lithium batteries seem to be getting good remarks. Will be interested to see if increased competition helps drive the USA-branded lithium batteries downwards in the future.

AGM vs Lithium Battery Cost Comparison

AGM "Deep-Cycle" Battery
Chinese Brand Lithium Battery
American Brand Lithium Battery

2. Energy Density

Lithium-ion batteries have a much higher density compared to AGM batteries. This means, lithium batteries are able to store more energy per unit weight and a 100Ah lithium battery is considerably lighter than a comparable 100Ah AGM battery.

For example, a Battleborn Lithium Battery is 31lbs. But a comparable AGM batter is 64lbs

3. Practical Usable Energy

Technically, a 100Ah AGM and a 100Ah Lithium battery have the same amount of usable energy. But practically speaking, the actual amount of usable energy differs between these two batteries.

A typical AGM lead acid battery is not advised to be discharged past the 50% threshold. Doing so too many times severely reduces the total lifespan of the battery.

A typical lithium-ion battery can conservatively be discharged to 90% without severely reducing the total lifespan of the battery.

The reality of this consequence means that you would need a larger AGM battery bank to have the same practical usable energy as with a lithium battery bank. More AGM batteries means more weight in your campervan and more money spent on batteries.

4. Practical Lifespan

Even when you monitor a battery’s depth of discharge, lithium batteries have significantly longer lifespans than AGM batteries. This means lithium batteries have a large number of “charge cycles” than AGMs. A “charge cycle” is the process of discharging a battery and charging it back to it’s original point. If keeping an AGM battery at strictly a 50% DoD, a typical AGM can expect to have a total of 1,200 total charge cycles. If keeping a lithium battery at strictly a 80% Dod, a typical AGM can expect to have a total of 4,000 total charge cycles. The implications of this means that you can expect a typical lithium-ion battery, discharged under ideal situations, to have at least a 3x longer lifespan than an AGM discharged under ideal situations.g

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Which Is Ultimately Better? AGM or Lithium?

By now, you might think that lithium batteries are simply the better choice compared to their AGM counterparts. And in many cases they are. Lithium batteries are lighter, have longer lifespans, and can be safely discharged to greater depths than AGMs.

We also have lithium batteries in our own campervan, so we’re a firm believer in them as well.

However, there are several scenarios in which an AGM battery is more advantageous than lithium.

1. Budget Limitations: If you’re on a tight budget, spending additional money upfront for lithium batteries might just be unrealistic. We understand that not everyone has an additional $1,000 (or more) to spare.

2. Short Term Travel: Because lithium batteries have a substantially longer lifespan, they are great options for people who plan to live and travel in their van for a long period of time. But if you only expect to life in your camper for roughly a year or less, the advantages of lithium’s longer lifespan is negated.

3. Traveling In Extreme Cold: Not mentioned above, but AGMs actually perform better in freezing temperatures. Below freezing, it becomes dangerous to try to charge lithium batteries. In fact, the popular Battleborn lithium battery is programmed to stop receiving charge at 24F. If you think traveling in extreme winter environments is in your future, the more robust AGM batteries may be your best bet.

Why Lithium Batteries Are Better For Us

AGM vs Lithium - Lithium Batteries Are Better For Us

In our specific case, we decided that going with lithium-ion batteries made the most sense. If you’re wondering why, we list every reason for this decision below.

Reason #1: Our Budget Allows It

In our previous lives before van life, we had decent paying jobs back in Asia. Yuko was working as a graphic designer in Tokyo and Eric worked in the healthcare industry in China.

Knowing that we wanted to travel long-term in the future, we began to save pretty hard and honestly led fairly frugal lives.

As a result, spending close to $3,000 for three 100Ah lithium batteries was not financially out of our reach. Although we definitely felt the sting in our wallets!

Reason #2: Long Term Travel

When we set out to build our DIY campervan, we knew right away that we wanted to drive the Pan-American “highway” from Canada to Argentina.

So we already knew that we would be on the road for AT LEAST two years. Actually because of Covid-19, we spent more than one year traveling in Mexico, waiting for Central American borders to open up.

Our length of travel made it easier to go with lithium batteries, knowing that lithium batteries were rated for longer lifespans than their AGM counterparts.

Reason #3: We Are High Energy Users

With all the different electrical devices we wanted to connect to our batteries, we knew that our daily energy consumption would be quite high.

Our fridge, laptops, Instant Pot, and diesel heater are no energy lightweights!

Knowing this, we needed a battery that had greater depth of discharge capabilities without any lifespan degradation. Lithium batteries fit that profile.

Reason #4: We Are Weight & Space Conscious

To get an equivalent amount of usable energy with AGM batteries, we would need six 100Ah AGMs. Our Ford Transit campervan isn’t particularly small, but we certainly don’t want to sacrifice space six AGM batteries. And not to mention six AGM batteries will weigh almost 400lbs. But by going with lithium batteries instead, not only do we save three batteries worth of space in our campervan, we also save roughly 300lbs of weight.

Learn More About Campervan Electrical Systems

Overview: Are Lithium Batteries Better Than AGM Batteries?

If you looking for the quick and easy answer, then yes, lithium batteries largely out perform AGM batteries in many of the head-to-head comparisons between the two. And this is especially true in the campervan space.

Lighter, more energy dense, longer lifespan, and greater depth of discharge means that lithium batteries are the future for those of us in the van life community.

But it’s crucial to understand that AGM batteries aren’t dead, yet, and provide very real and valuable solutions to select groups of people in the campervan community. What’s important is to understand what your needs and situation are and what it is that you want to get out of van life. Only then can you go about picking the right type of battery for you.

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