Why Install Self-Heating Lithium Iron Phosphate Batteries?

Why Install Self-Heating Lithium Iron Phosphate Batteries?

By Shari and Hutch
Shari and Hutch
renogys blog Sep 5th 2023

You have finally decided to switch out your old lead acid RV battery for a lithium battery. But, which are the Best Lithium Iron Phosphate batteries for your RV lifestyle? It simply depends on how you plan to use them.

Do you use your deep cycle RV batteries to…

● travel in (or even through) colder climates to get somewhere warm?

● visit national parks in the off-season to avoid crowds?

● go ice fishing?

● head to the mountains for winter sports?

● work online from the road during the winter?

If you answered YES to any of these questions, spending a bit of extra money for a self heating lithium iron phosphate battery bank will be a game changer for you!

Standard LFP Battery vs. Self-Heating LFP Battery – What’s the Difference?

When comparing the overall specs and features of the 12V-100Ah Smart Lithium Iron Phosphate and the 12V-100Ah Self-Heating Lithium Iron Phosphate battery, you’ll find that they are nearly identical. Both of these LFP batteries provide 1280 Watt Hours of energy per cycle at a safe 80% depth of discharge, both have an average of 4000 lifecycles (10+ years of service!), a maximum continuous charging current of 50A and discharging current of 100A, a Battery Management System (BMS), are Bluetooth capable using a BT Module, and carry a 5-year warranty.

While standard LiFePo4 batteries work well in temperatures ranging from -4°F to 140°F, the major drawback of LFP batteries for RVers who want to travel in colder temperatures is that they have a more limited temperature charging range, from 32°F to 131°F. Simply put, standard LFP batteries don’t work well in extreme cold and can be dangerous when too hot, which is why they are often happier stored inside your rig, rather than out on the trailer’s tongue. Like to nerd out a bit? Learn how battery chemistry is affected by cold temperatures in this blog.

So, what’s the major difference between these 2 types of LFP batteries? It’s how the BMS responds to freezing temperatures. When the BMS of the standard LFP senses that the core temperature of the battery is below 32°F, it shuts down the battery’s ability to charge so that it won’t damage the battery. But, when the BMS of the self heating battery senses that the core temperature of the battery has dropped below 41°F (and has at least 4 amps of power coming from any charging source*), a small self heater kicks on to keep the battery at an optimal charging temperature – allowing it to charge up and making it more efficient. As you can imagine, this self heating feature is a complete game changer for adventurous folks like us who travel year round, even in the winter!

*LFP batteries can be charged via solar panels, your engine’s alternator via a DC to DC charger, shore power, and if you must, a gas powered generator.

Why Choose Self-Heating LFP Batteries?

We have lived, worked, and explored the North American continent while traveling in our restored vintage travel trailer since the fall of 2012. While we often travel in warmer climates, it is not always in the cards for us. We also love to camp and hike among autumn colors, snowshoe and snowboard out west, and visit family and friends during the holidays who live in cold, wintery places. Even the southwestern desert can get pretty chilly in the winter. On a few occasions over the past couple of years, our standard 100Ah LFP battery got too cold to accept a charge. To remedy this situation, we had to warm the battery using our portable propane heater and a 12V fan to blow warm air into the battery compartment. While this has worked, it was a bit comical and it limited our ability to make use of either our solar panels or our 30A Dual Input DC to DC charger to charge our RV battery until we could get it above freezing.

Why We Doubled Our LFP Battery Bank Capacity?

While we have prided ourselves on being energy efficient and thriving with less for nearly 11 years, our mobile business is thriving! We are doing twice the video production work that we did when we started our business just 2 years ago, and our biggest energy hog is the graphic intensive gaming laptop that we use for this purpose. Also, we just added Starlink Roam for fast and reliable internet while we are completely off-grid so that we could work online from anywhere we happen to be -- whether it be the beach, mountains, or deserts of the United States, Canada, or Mexico. While Starlink has allowed those of us who live a mobile lifestyle to work online, we needed a second battery in order for us to run everything. Just a couple of weeks ago, we installed 2 x 100Ah Self Heating LFP batteries in parallel, giving us a 12V system that has 200Ah (approximately 2050 Watt Hours of energy) at a safe depth of discharge of 80%. This step-by-step installation video is now available on our YouTube channel.

Double Your Battery Capacity without Expanding Your Solar Array

We choose to live in a small space, with limited storage, and have limited space on the roof of our vintage camper. We have 2 x 100W flexible solar panels on the roof, plus a 100W foldable solar suitcase on a 20ft extension cable that we use to charge when we are parked in the shade and/or to boost our solar charge on a cloudy day. This has been all we’ve needed to keep our previous Renogy 100Ah battery topped off. But, now that we have twice the battery capacity, we need twice the charging current.

Without room for additional solar panels on our roof or in our storage area, and no desire to get a bigger rig, we had to get creative! A couple of years ago, we installed a Dual Input 30A DC to DC charger along with a 50Ah LFP battery in our towing vehicle to run our 12V ICECO fridge using our engine’s alternator.

With this system in place, we recently added a very inexpensive dual battery switch in the back of our towing vehicle which allows us to easily switch between using truck’s engine to charge our 50Ah LFP battery (fridge) and our 200Ah battery bank (camper) via Anderson connectors between the truck and trailer. Now, we can deliver 30 amps of current to our house batteries (plus any additional solar charge we happen to be getting from our rooftop panels), and our new 200Ah self heating battery bank is recharged to 100% within a couple of hours! It is a clever, effective, and inexpensive way to make use of our existing system without having to add extra solar panels. So, if you typically drive every few days, using a DC to DC charger can augment your solar array significantly. DC to DC chargers come in various styles and sizes – check out this blog to learn how to size one that is appropriate for your needs.

So far, we are very pleased with this upgrade to our system. We are currently boondocking on the coast of Haida Gwaii island, British Columbia with our solar charging, our Starlink allowing us to get some work done, and the coffee brewing. Stay tuned…we’ll check back in later this year when we are traveling in colder climates to share our experience with the self heating aspect of the batteries. Until then, feel free to reach out with questions!

In 2012, Shari Galiardi & David Hutchison left behind careers and a comfortable home in North Carolina to travel with the vintage camper trailer they lovingly restored, outfitted with solar, and named "Hamlet." What began as a short break from careers and responsibility quickly turned into a love affair with roadlife. They have parlayed their higher education backgrounds, desire for life-long learning, and thirst for adventure travel into writing, photography, video production, and public speaking gigs from coast to coast. Known to their friends as simply Shari & Hutch, you can learn more about their full-time, solar-powered adventures on their website at freedominacan.com. Or, follow them on Facebook, Instagram, and YouTube as “Freedom in a Can, LLC.”