Going Lithium: LiFePO4 Batteries For the Truck Camper Adventure Rig

Yep, we did it. We finally swapped out our old Lifeline GC AGMs for a pair of Expion360 Viper 120 amp hour lithium (LiFePO4) batteries. Why go through the trouble and expense? Because the lithium battery is worth it. Unlike the standard lead-acid battery, which offers only 50 percent usable capacity, the lithium battery offers a whopping 90 percent. This is a significant improvement for those who like to boondock. But that’s not all. The Lithium battery also weighs less, provides a higher current output, charges faster because it can be bulked charged to 100 percent, and offers zero voltage sag. It also lasts longer. Of course, the only real negative with the lithium battery is the initial price—the cost for an Expion360 Group-24 Viper battery is an jaw-dropping $1,300, three times more than a standard AGM battery—but when it comes to the pros in an RV, nothing beats a lithium battery. Nothing.

The first thing we noticed when installing the new Viper lithium batteries is the weight—lithium batteries are incredibly light. Removing the old, 66-pound Lifeline 6 volt AGMs was a chore. I had to take extra care to lift each battery with my legs to protect my back. In sharp contrast, handling the 32-pound, Expion360 Group-24s was easy. Together, the two lithium batteries weigh only 64 pounds, while the total weight of the AGMs was a hefty 132 pounds. As you know, every pound matters in a truck camper. Weight isn’t a major concern for our one-ton rig, but it is for many truck camper owners who own half-ton and 3/4-ton trucks with smaller payloads. Many truck camper owners are over the GVWR and payloads of their trucks. Having lighter batteries can make a world of difference in the final set-up.

Of course, the biggest improvement we’ve seen is with the increase in usable amp hours. Our Expion 240 amp hour lithium battery bank provides us with 216 amp hours of usable capacity. Our old 220 amp hour AGM battery bank gave us half of that at 110 amp hours. What we’ve essentially done is cut the total weight of our battery bank in half and double its size—216 amp hours at 64 pounds vice 110 amp hours at 132 pounds. This is like having four AGMs in our camper now. This is HUGE. You can’t beat the amp hour to weight ratio of a LiFePO4 battery. This is even more important, of course, in a truck camper where space is always at a premium. Many truck campers have small battery compartments that can hold only a single Group-24 battery. With the lithium battery, you can double the usability of that compartment.

The BMS in every Expion360 battery features an excellent LED status indicator.
View showing the removable BMS useful for servicing.
Our new LiFePO4 capable Zamp ZS-30A PWM Charge Controller.

The Battery Management System (BMS) found in every Expion360 Viper lithium battery is a key component and where Expion360 really excels. The BMS protects a lithium battery from short circuits, limits input and output currents, and provides over charge and over discharge protection for the battery. What’s great about the Expion360 lithium battery is that the BMS in each is removable and serviceable. The BMS found in other makes are not, they’re sealed within each battery, rendering servicing impossible. This makes Expion360 battery repairs much cheaper and easier in the long run. At first, this feature might not be a big deal, but may be in five or six years when BMS components start failing. A BMS repair that costs $200 is much more preferable than replacing a $1,300 battery—the choice is yours.

Another thing we really like about Expion360’s Battery Management System is the LED indicator light. When the light is solid green, the battery is operating normally. When the light is blinking red, the BMS has recognized a fault, but has not yet disconnected the battery bank, this is a warning light status. If the problem has not been resolved, the BMS will disconnect the battery bank to protect the individual cells in the battery from damage. When the BMS is in a full protection state there will be no LED warning light on. According to Expion360, one of the main reasons the LED status light will blink red or shut off is that the Viper is empty or almost empty and is at its lowest voltage reading. To reset the BMS, all you need to do is connect the Viper to shore power to recharge. Pretty cool!

Warning! One thing you should NEVER do is charge a lithium battery below freezing. This will irreparably damage the battery. One thing we’ll need for these batteries is cold charge protection, either a cutoff switch or some kind of thermostat with a relay. If you connect all your charging sources on that relay, it will only be closed when the battery temperature is above freezing. Keeping the batteries inside should really help, especially when using the camper and running the furnace, but keeping them inside won’t entirely eliminate all risks when the camper is stored and not in use. Of course, many lithium battery owners get around this problem by simply removing them from the camper during the winter and reinstalling them in spring.

We highly recommend going lithium, but be warned. Going lithium means you’ll probably incur additional expenses. This includes buying a LiFePO4 compatible solar charge controller, a 110 volt converter-charger capable of generating 14.6 volts during bulk charging, and the aforementioned cold charge protection needed to prevent your lithium batteries from being charged below 32 degrees.

Stay tuned here and on Instagram for updates, mods, and an in-depth review on how our lithium batteries perform.

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About Mello Mike 447 Articles
Mello Mike is an Arizona native, author, and the founder of Truck Camper Adventure. He's been RV'ing since 2002, is a Jeep and truck camper enthusiast, and has restored several Airstream travel trailers. He currently drives a 2013 Ram 3500 4x4 pickup truck with a 2016 Northstar Laredo solar powered truck camper mounted on top. He enjoys football, music, hiking, travel, photography, and fishing. He retired from the U.S. Navy in 2004 as a CWO3 after 24 years, worked in project management until 2017, and now runs this website full-time. He also does some consulting and RV inspections on the side.

8 Comments

  1. Just to answer the question, the 2150S Odessey extreme group 31 is rated at 400 cycles to 80% DoD. I know, does seem low. I did not quickly find a 50% DoD number, so I used the mfg. provided 80%. The cost today is around $400.

    The Expion 360 is rated to 2500 cycles min at 80% DoD. Cost is what, $1300?

    So going by manufacture specs, Expion offers 6x the life at just over 3X the cost.

    But if the AGM lasts you 15 years, why pay more? For a fulltime boondocker, the LiFePO4 might offer a lot of advantages (and the AGM will not last 15 years in that use case).

  2. Mike, did you write and do this? I hope so as I hope you keep us in the loop on how this performs.

    I have 2 Odessey Grp 31 extreme batteries, my cost was about $300 each with free shipping, they are about 8 years old. I have 1 other, about 13 years old I paid $200 for. This one was in my Truck camper for years, then in 3 Jeeps, 3 F 350 diesel trucks and my wife now uses it in her business to power lights when she attends shows, about 30 shows per year. At full charge its good for 13.3 v. I bring this up because as a retired engineer I lived with a thing we called:n Full life cycle cost model. The cost of that model of Litn online is $1340 each. 1 Lith costs as much as about 4 of my Odessey Extremes. This begs the question which is the better buy for the long haul? I don’t know, but hope you can shed some light on this. I expect to get 15 years out of my Odesseys.

    • Hi Don. Yes, I wrote this and, yes, we’ve installed these in our camper. We are evaluating them now and will publish a review in six months. You bring up great points, but so far, we love the lithium. Two Group 24 lithium batteries is like having four AGMs and the two only weigh 64 pounds total. We’ll post more when its time.

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