This past week we've been camping in northern Arizona and New Mexico, with temperatures dipping down to 20°F at night. This was the kind of trip where we needed a lot of battery power, since the furnace was running a lot and we were sometimes camping with no power hookup.
It wasn't a problem. In fact, we hardly even thought about power, because a couple of years ago we upgraded from lead-acid batteries, to lithium batteries that yield about 3X as much power. (You can read the details in this guide, Diary of a Lithium Battery Upgrade.)
Why you should make the switch
Typically, a pair of lithium batteries that fit into an Airstream trailer battery box will yield 200 amp-hours (Ah) of power, or about 2,560 watt-hours (Wh) if you prefer that measure. Any way you measure it, that's so much power that, on many trips, we don't need solar panels or power connections. We can use all the electrical devices we want, including laptops, the inverter, TV/DVD, furnace, etc., without worrying about running out of power on a weekend.
Not only that, but lithium batteries weigh less, last longer, and recharge faster than lead-acid batteries. For RVers they are clearly superior – unless you never camp without an electric hookup and don't really use the batteries.
Yet despite the obvious advantages, we still hear a lot of misinformation about lithium batteries when we talk to Airstreamers and other brand RV owners. Let's address some of the most common questions:
1. Aren't lithium batteries a big fire risk?
No. Fortunately, this is not a worry for RV owners. To understand why, you need to understand that there are two major types of "lithium" batteries:
- Lithium ion batteries are commonly used in e-bikes, laptops, electric cars, and other consumer devices
- Lithium iron phosphate batteries–often referred to as LiFePO4 or LFP– are the type used in RVs (and some electric cars)
The RV industry only installs LiFePO4 batteries in RVs, and they have an internal cathode made of phosphate, which won’t burn very easily. They also don’t have the "runaway" thermal problem that lithium ion batteries do. So they are highly unlikely to catch fire.
2. Is it safe to install lithium batteries inside an RV – like under the beds or dinette?
Yes. Unlike lead-acid batteries, lithium batteries don't produce flammable gas, and don't contain dangerous acid. They're safe to be inside the trailer or motorhome.
3. I've heard you can't store lithium batteries at 100% without damaging them. Is that true?
Although it's true for lithium-ion batteries, it's not true for the LiFePO4 batteries that RVers use. Although lithium-ion batteries don't like to be kept at 100%, it's no problem for LiFePO4 batteries. You can charge them to 100% as often as you want, and even leave them in storage that way. The lifespan of a LiFePO4 battery isn't significantly affected by being kept at 100% charge.
If you read this "can't store lithium at 100%" myth online or hear it at a rally, you can tell the person that they are talking about lithium ion batteries, not LiFePO4 batteries.
4. Can lithium batteries be damaged if they are used below freezing, without a built-in heater?
Not at all!
On our recent trip, we camped for many nights below freezing, and enjoyed plenty of battery power, despite the fact that our batteries are stored in the outside battery box and they don't have heaters.
You can use a LiFePO4 batter to power your Airstream below freezing without a problem, all the way down to 0° F. You just can't charge them much below freezing.
If you try to charge LiFePO4 batteries below freezing, the charging process will automatically be shut off to protect the battery. That’s because any good LiFePO4 battery has “smart” technology, in the form of a Battery Management System (BMS) that works to prevent the battery from being damaged. When the temperature drops to about 25°-32° F, the BMS will shut off charging. When the sun rises and the temperature climbs above 32°, the BMS will accept a charge again.
Because of the "smart" BMS technology, you won't damage your LiFePO4 batteries by camping in freezing temperatures. They simply won’t charge until it gets warmer. Since you're probably using solar panels to recharge them you won't even notice this, because you're not trying to charge the batteries at night.
If this is a problem based on how you travel, you can get LiFePO4 batteries with little built-in heaters that enable you to charge the battery in sub-freezing temperatures. They run about $40-50 more per battery and brands such as Battle Born and Renogy offer them.
Most Airstreamers don’t need heated LiFePO4s. Only if you need to charge when you're in places where the temperature stays below freezing both night and day do you really need them. If that's not how you travel, you can save about $100 by purchasing unheated LiFePO4 batteries.
5. How do I winterize my lithium batteries?
Easy! As long as you don't live in an area where the temperatures drop below -10°F, you can just make sure the batteries are fully charged, and then disconnect the negative cable from the batteries. (The "Battery Disconnect" switch in your RV may not fully disconnect everything, which is why disconnecting the negative cables is better.)
Lithium batteries don't "self-discharge" nearly as much as lead-acid batteries do, so you can leave them in this state for 3-4 months without any problem at all. If your batteries have a "storage mode" or "shelf mode", follow the manufacturer's instructions to activate it and they'll last even longer.
6. Which lithium battery brand should I buy?
Stick with reputable brands that are commonly used in RVs, like Battle Born, Renogy, Expion 360, Victron, and Lithionics. Watch out for "bargain" lithium batteries. If the battery you're considering is half the price of a well-known brand, there's a reason. They may have skimped on the BMS (which can be dangerous), they might be using inferior cells, the warranty may be short, and there probably isn't any US-based support from the manufacturer.
23 comments
Darrall Henderson
So happy I upgraded to two heated LiFePO4s. They fit in the same battery box and no more worries about running out of power on a 3-4 day trip in the winter.
Gil Jarvie
Great contact, Rich, and information that was new to me. I always appreciate the “myth busters.“
Imelda
Thanks for settling the myth debates about Lithium Ion and Lithium Iron batteries. Within 2-3 years, we’ll upgrade our AGM’s to Lithium Iron. Our AGM’s have been great for 5 years now but won’t last forever. Those batteries and a 100w portable solar panel allow for the boon docking that we love.
Ed Fincher
I love my Renogy upgrade, have a 2018 27’ Globetrotter that the AGMs had died during storage. Did an upgrade as Rich did & it has been a game changer on boondocking.
Ric Jones
Excellent article and nice, concise information for newcomers to LifePO batteries. The additional power available from Lithium batteries is astounding. And at far less weight. A 100 Amp Hour LifePO battery can weight about 26 lbs while my 60 Amp Hour AGM weights more than 50 pounds. I get 30 Amps of power from that 50+ pounds. For the same weight, I would get 200 Amps of power from Lithium. (2 × 100 AmpHr x 26 lbs each).
elly
I’m going to keep this link handy to give people who give me a hard time for using a LiFePO4 battery in my Airstream. Thank you!
Sheila Simms
Planning on updating to the LifeP04 before our next trip we have a 2022 Airstream
Richard Everson
Excellent
Donald Wright
Thank you Rich, this was very helpful. Do these batteries need to be inside the trailer or in the standard tongue battery box.?
Rich Luhr
Donald, they’re fine in the standard battery box. That’s one of the reasons the upgrade is easy: you can find LiFePO4 batteries that are “drop-in” replacements for your existing batteries.
John Wesp
If you install lithium batteries in a 2019 globetrotter
DO YOU NEED TO CHANGE ANY OTHER PARTS??
Stan Beagley
So to be clear, I can drop these batteries in the same box and not adjust anything else?
Rich Luhr
John Wesp and Stan Beagley: Before you can switch to LiFePO4 batteries you may need to upgrade the Airstream’s battery charger and/or solar charger. It depends on your year and model of Airstream.
For details, see our “Diary of a Lithium Battery Upgrade” here:
https://www.airgear.store/pages/diary-of-a-lithium-battery-upgrade-a-planning-guide-for-airstreamers
… OR the Spring 2023 issue of Airstream Life magazine
… OR pages 188-189 of "The (Nearly) Complete Guide to Airstream Maintenance.
Joseph Claypool
When I stored my rig this winter for a few weeks the Battle Born customer service tech recommended a full disconnect instead of just removing the negative cables. They said they always recommend a full disconnect anytime when storing.
David Tait
Will I be able to just drop 2 LiFePO4 batteries into my 2017 23FB International with out any modifications ?
John Hardt
We upgraded to lithium batteries and haven’t looked back. In addition to the advantages you mentioned above we also dropped about 50 pounds off of our trailer’s previous tongue weight.
Barry
Is it required to disconnect the truck alternator from the 7 way plug for lithium batteries?
John Wolf
I wish Airstream would build the battery boxes big enough to accommodate two Battleborn style batteries. Battery cables are made of heavy wire to manage electrical loads. Space in the box is very tight, I hardly have enough room in my 2023 Globetrotter battery box. I don’t want to move them inside the camper, Storage inside is limited enough,
Marc Tanner
Hi Rich. I have used Lithium iron batteries for 5 years. Two on boats, on one we even did a Transatlantic crossing from Cape Town to Ft. Lauderdale..
Now I have 2 330Ah Victron LiFePo4 batteries in my Airstream. I LOVE them. These are the batteries that complement solar perfectly. They accept any charge that the solars throw at them without flinching whereas Pb don’t once they are above 65% SOC. PLUS Lithium batteries have the full capacity that is printed on them, Pb only 50%.
Rich Luhr
David T: There’s a bit more to it than that, for your Airstream’s model year. You’ll need to update the charge controller and possibly also solar controller. For details, see our “Diary of a lithium battery upgrade”. There’s a link in this blog.
Rich Luhr
Barry: No, you shouldn’t disconnect the truck alternator from the 7-way plug. The truck will continue to charge lithium batteries if you leave it alone.
John W: Airstream does make their battery boxes large enough to fit two Battle Born 100-amp hour batteries. They recommend Battle Born 100Ah 12V GC2. You can also fit two Renogy RBT100LFP12S batteries in your Globetrotter’s battery box.
Barry
I have read somewhere that the voltage to charge lithium batteries was different from lead acid and that a truck alternator didn’t produce the correct voltage? Wondering if that was why people like 13 adventures installed a dc-dc charger in truck?
Rich Luhr
Barry: Lithium batteries do require a higher voltage (typically about 14.4 volts) to reach 100% capacity, but your truck alternator will get them above 90% in most cases.
The primary reason to install a DC-DC charger is to increase the charging speed while towing. A typical 7-way plug will output only about 4-5 Amps, which means slow charging. A DC-DC charger can multiply that rate, but for most people it’s not needed since they’ll charge at their destination anyway (via a plug or solar).