Words and photos from 
4wd talk
A few months ago, I upgraded the batteries in my Turtleback Expedition Trailer with dual Ultimatron 100AH lithium batteries.
Now that I’ve had some time in the field with these batteries, I thought I’d give you my two cents on how these batteries have performed under pressure.
As you probably already know, lithium batteries offer significant advantages over AGMs, but there are also a few drawbacks to lithium batteries. The question is, have these Ultimatron batteries been a good or bad investment? Let’s find out in this Ultimatron lithium battery review!
Why Lithium Batteries?
As I noted in the introduction, I’m assuming you already understand why so many overlanding enthusiasts like me are switching from AGM batteries to lithium batteries. But, if not, here’s a quick rundown of the advantages of batteries like the ones I got from Ultimatron.
First, lithium batteries have a far greater depth of discharge than AGMs. A typical AGM battery can be discharged to about 50 percent, while a lithium battery can be discharged all the way to 100 percent. That’s not a small difference!
Now, running lithium batteries down until they’re dead doesn’t help the battery’s longevity, but the power is there if you’re in a pinch and need it.
Second, as I explain in the video above, lithium batteries have a much longer life cycle than AGMs. You can bank on about 900-1,000 cycles for AGM batteries. You can get about 5,000 cycles out of lithium batteries. Again, that’s not a small difference!
A third advantage is that my Ultimatron lithium battery set offers improved power output over the AGM batteries that came with my trailer. You can run devices that need higher amperage (e.g., air conditioning, kitchen appliances) off of lithium batteries, so if you’re like me and you have a toaster, a coffee maker, and other power-hungry appliances as part of your overlanding rig, lithium batteries are where it’s at.
Fourth, lithium batteries are lighter and have a smaller form factor than AGM batteries. In fact, my Ultimatron lithium battery set weighs about half as much as the original AGM battery set that was in my trailer.
When you’re overlanding, you have to be very careful about how much weight you add to your rig. Likewise, you only have limited space for all your stuff, so having smaller, lighter batteries is certainly a good thing.
Of course, my Ultimatron lithium battery set has other advantages…more on that below!
Ultimatron Lithium Battery Basic Specs
As I just noted, lithium batteries are typically much smaller than AGMs. As evidence of that, one Ultimatron lithium battery is just 12.91″ x 6.77″ x 8.35″ and weighs about 25 pounds. They’re small enough that I could install them next to one another in the nose of my trailer, in a spot that’s out of the way and still enables me to have ample storage space.
These batteries are 100Ah each, with an operating voltage range of 10-14.6V and a nominal voltage of 12.8V. The charging voltage is 14.6V.
Each Ultimatron lithium battery has a recommended charge current of 20A and a maximum charge current of 50A. The maximum discharge current is 150A.
If I run these batteries to a depth of discharge of 80 percent each and every time, I can get about 3,000 cycles out of them. But, if I reduce the depth of discharge on most of my trips to about 50 percent, I can extend the life of each battery to more than 5,000 cycles.
One of the knocks against lithium batteries is that they tend to be more sensitive to cold than AGMs. However, the Ultimatron lithium battery set I have in my trailer has a discharge temperature range of about -4ºF to 140ºF and can be efficiently charged at temperatures from about -4ºF to 113ºF. They can also be stored in cold temperatures – around 23ºF to 95ºF.
Ultimatron Lithium Battery Features
Beyond the technical specifications discussed above, the Ultimatron lithium battery set in my trailer offers some unique features that make them highly functional and easy to use.
For example, each battery has a built-in heater to help them start a normal charge in cold weather. I like to do my fair share of cold-weather camping, so this is a crucial feature for my outdoor adventures.
Another handy feature is the built-in battery management system. These batteries connect to my phone via Bluetooth, which enables me to monitor the performance of the batteries while also helping prevent overheating, overcharging, and overvoltages.
On top of all that, Ultimatron offers a five-year warranty on their batteries, which gives you long-term peace of mind that if something were to go wrong, they’ve got your back.
What’s also impressive about these batteries is the build quality, reliability, functionality, and innovative technology Ultimatron has used. These batteries use the safest and latest technology and have no risk of fire or explosion. They’re purpose-built for a long service life and have no memory effect and no need for full charge and discharge cycles.
In other words, my Ultimatron lithium battery set has turned out to be the ultimate battery setup for my needs
How I Installed My Ultimatron Lithium Batteries
As you can see in the video above, I installed my Ultimatron lithium battery set in the nose of my trailer. These batteries fit snugly in the bottom of the storage area and were a breeze to connect to the other electrical components in my trailer, like the REDARC Manager30 system.
Of course, these Ultimatron batteries are just one of many upgrades I’ve made to my trailer over the years, so be sure to watch the full video above for a complete tour!
Final Thoughts
So, as I’ve made obvious in this Ultimatron lithium battery review, these batteries have absolutely impressed me from moment one.
From every standpoint, these are the best batteries I’ve had in my trailer. They offer more functionality, better ease of use, and provide all the power I need for my trailer’s systems for extended periods of time.
Sure, lithium batteries like these are pricey up front, but they more than pay for themselves with their long-term reliability, depth of discharge, and the number of life cycles you can get out of them.
I had a different brand of lithium batteries in my trailer before, and they were perfectly fine. In fact, at the time, I couldn’t imagine how another brand could be better. Yet, Ultimatron proved that their batteries are better than the previous ones with special features like the built-in heating system, the control app on my phone, and the build quality and warranty I spoke of earlier.
So, that’s a big thumb’s up from me for this Ultimatron lithium battery set. If you’re ready to level up the power system in your rig, give these batteries a try!
