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Ask Dave: Why did the lithium battery explode and flame up?

Answers to questions about RV Repair and Maintenance from RV expert Dave Solberg, author of the “RV Handbook” and the managing editor of the RV Repair Club. This column appears Monday through Saturday in the RV Travel and RV Daily Tips newsletters. (Sign up for an email reminder for each new issue if you do not already receive one.) Today Dave discusses lithium batteries.

Lithium batteries

Dear Dave,
On a camping trip, our neighbors had a lithium battery that exploded and flamed up. I tried to put it out with my fire extinguisher. It helped, but I read later that you need to use water and special blanket, or a class D extinguisher. In your opinion, how safe are lithium batteries, and what precautions should one take with them? Thanks. —Les

Dear Les,
There are several aspects to your questions, which are great. Hopefully, nobody got hurt.

First, I think it is imperative for every RVer to educate themselves on fire safety. I helped produce the RV Safety and Education Foundation’s 9-course safety program several years ago. We did extensive research with Mac “The Fire Guy” McCoy. Mac is the leading expert on RV Fire Safety and used to conduct seminars at rallies and conventions. He was also a contributing writer for several organizations, including RVtravel.com.

We shot several videos, and one of the critical ones was knowing how to use your onboard fire extinguisher.

For years, the fire extinguisher by code has been the 10 BC-rated extinguisher. It will only be effective in 10 square feet and only cover a B- or C-type fire. This means it is not effective on an A-type fire. That is anything that can leave an ash, such as wood, carpet, fiberglass and more. That is the majority of most RVs! Hopefully this has changed recently, but 10 square feet is a small space to be effective!

Types of fires

Class A – Trash, wood, paper, or anything that will leave an ash

Class B – Liquids such as motor fuels or propane

Class C – Electrical equipment

Class D – Combustible metal

If your rig had a 10BC fire extinguisher, it would be effective on the electrical part of the equation, but not on the Class A, which would have been the battery cases, compartment liner, sidewall material and others.

A Class D fire is defined as a combustible metal such as magnesium, aluminum, and even lithium.

I do think the fire blanket is a good choice and you can find them at Amazon.

I suggest RVers purchase a larger rated unit that covers A, B, & C class fires. In fact, I suggest you get several extinguishers. Have one inside the rig, one in the bedroom, one in storage, and another in a tow or towed vehicle. This is not to scare people, and I’ll get a ton of comments that it’s overkill and not necessary. However, it only takes once, as you have experienced. Then learn how to use the extinguishers and remember where they are located.

High quality lithium

Now, to the second part of the equation: Why did it happen and what can be done to prevent or reduce the chances of it happening?

I am not that familiar with lithium technology, so I contacted my source at Expion 360. I have worked extensively with Zamp Solar. The founder, John Zamp, sold the company (now Dometic) and started Expion 360. Here is what I have learned.

Without having information on the type/brand of battery involved in the issue, the charging system, and the type of installation, it’s impossible to determine what caused the failure. Plus, was it a gradual overheat situation that actually started some other material close to the battery, connections, or charger on fire? Lithium battery fires are fairly uncommon, so it’s hard to pinpoint the exact cause without having more information.

However, what research they do have with cheaper batteries over the years is overcharging and incorrectly fused components on inexpensive batteries causing failures.

As with anything, you can always go cheaper. If the public doesn’t know the difference, they will buy on price. This is so huge in the RV industry. The higher-priced lithium batteries utilize UL-rated steel casted cells and a battery management system.

Upgrading to lithium batteries

Mike Sokol has great articles about upgrading batteries and how you can’t just drop a new set of lithium batteries in your unit without making sure your charging system is compatible. As I’ve written several times, the conventional charger with your distribution center, called a converter, sense the batteries are low and just ramps up a 13.6-volt charge until the batteries reach 12.6 and then drops off to 13.2 volts. A multistage charger such as an inverter, solar panel with charge controller, or Progressive Dynamics charge wizard will do the multistage charge. They are not compatible with the lithium battery charge protocal and could overcharge if not set up correctly.

As a final note, the Expion battery has a battery management system that will sense extreme overcharging and discharging as well as temperatures to reduce the potential of such a disaster. I would suggest checking them out here: expion360.com/pages/rv

Major points: Get good batteries, make sure they are compatible with your charging system, get the right fire safety equipment for your needs, and understand how to use it.

I applaud you for the assistance and request for more information! Thanks!

Read more from Dave here

Dave Solberg worked at Winnebago for 15 years developing the dealer training program, as marketing manager, and conducting shows. As the owner of Passport Media Creations, Dave has developed several RV dealer training programs, the RV Safety Training program for The Recreation Vehicle Safety and Education Foundation, and the accredited RV Driving Safety program being conducted at rallies and shows around the country. Dave is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

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Tsippi
1 month ago

Thank you for this great article. I’m going to upgrade my fire extinguishers and purchase a fire blanket based on your advice. I wonder if you have considered an article on RV evacuation aids? Things I’ve tried to figure out but ultimately been frustrated by, given uneven reviews on available equipment: How will I prop the evacuation window open so I can lower the dog to the ground? Is there equipment to help me lower the dog to the ground? How will I (a petite, not very strong woman) fair climbing out of the window from my loft bed, which is eight+ feet off the ground? I’m guessing I’m not the only person who worries about these things. Thank you again for your great column.

Jeremy
1 month ago

Dave,

On questions like this it’s absolutely critical that you differentiate the most common “Lithium” batteries used in RVs (LFP) with the batteries used by electric vehicles.

There are a number of different battery chemistries that use lithium-ion. Some of these chemistries are very different from one another. Lithium Iron Phosphate, also written as LiFePO4 or LFP, is incredibly safe and almost impossible to push into “thermal runaway” which is what causes battery fires.

Go to YouTube and search for “lifepo4 safety test” to see what I mean. You can find videos comparing what happens when you puncture LiPo cells vs LFP cells and the results are drastically different.

LFP is very safe, safer than lead acid in fact. People should understand that lead acid batteries are *also* prone to fire and explosion if mistreated (And they are often installed right next to propane tanks) because lead acid can vent hydrogen and oxygen during charge, especially if the battery is older.

Paul Cecil
1 month ago

A good article that points to two needs. First, individuals need to educate themselves to newer batteries, how to install them, and any safety needs. Even if you don’t intend to do the work yourself you need to be able to know how to maintain the system and recognize issues before something serious occurs. This leads me to suggestion number two. This “Ask Dave” article seems to be a good lead in to a series of articles about RV lithium batteries. The types, systems, and what to look for. Oh, and where to find more information to educate ourselves.

Admin
RV Staff (@rvstaff)
1 month ago
Reply to  Paul Cecil

Hi, Paul. Good suggestions. Electricity expert Mike Sokol has written, and is writing, quite a few articles on lithium batteries. You can find them here: https://www.rvtravel.com/?s=lithium
Have a great day. 🙂 –Diane

DW/ND
1 month ago

Might be interesting to know what caused Chev. Bolts to suddenly explode into flames – last I heard, a couple weeks ago, was a news clip from GM advising not to park the car in your garage! What kind of batts. are in the Bolt?

Jeremy
1 month ago
Reply to  DW/ND

Chevy Bolt’s use an entirely different chemistry than what is found in most “RV Lithium” batteries. There are a wide range of battery chemistries that use lithium. Some are quite easy to push into thermal runaway by overcharging, overheating, or even physically damaging them. The type used in RVs, LFP, is actually quite safe and very difficult to push into thermal runaway. You can drive a spike through them and they will barely smoke.

I know some people who have built DIY RV batteries using “used” Tesla or Nissan LEAF cells because they are cheap. So it’s possible that’s what was being used here. But any “off the shelf” Lithium batteries made for RVs all use Lithium Iron Phosphate, which is nearly impossible to push into thermal runaway. Lead Acid batteries are actually easier to catch fire than LFP.

Chris Mead
1 month ago

The Boeing 787 experienced several battery fires. The common thread was excessive heat generated by excessive charge or discharge. The fix was to build a better enclosure.

Irv
1 month ago

It sounds like they purchased the wrong type of Lithium battery–but not enough detail as to the size and type of Lithium battery.

Lithium-ion batteries (such as in cell phones, and Electric Cars) have a much higher risk of fire than Lithium Iron Phosphate batteries (LiFePO4). LiFePO4 are the only type that should be used with solar in homes and RVs.

“LiFePO4 batteries are the safest type of Lithium batteries as they will not overheat, and even if punctured they will not catch on fire. … Due to the oxygen being bonded tightly to the molecule, there is no danger of the battery erupting into flames like there is with Lithium-Ion.” https://www.batterystuff.com/kb/articles/battery-articles/lithium-battery-overview.html

Thomas D
1 month ago

Sand is a go to for metallic fires. Call it what you will, something is flaming and things get burnt. a commercial dryer fan blade where i worked started on fire. Magnesium doesn’t go out with water as the responding fire dept found out. Remember the big fire in a new Boeing jet a few years ago. Lithium batteries! lots of power with reduced weight is great but cost and saftey is a heck of a price to pay.

David Telenko
1 month ago

Lithium battery fires are a VERY serious concern! I did a simple google search & found lots of valuable information about them & why they catch on fire & how to put them out. there are 3 links below & if you have or are considering a lithium battery for your RV, they should be read. You say it’s not for me as I don’t have a need for them! Think again as to what’s in your pocket right now, yes sir a cell phone with a Lithium battery!!!
Snoopy
https://www.youtube.com/watch?v=y95-08GSD9M&t=128s 

https://nbaa.org/aircraft-operations/safety/in-flight-safety/handling-of-hazardous-materials/lithium-batteries/dangers-lithium-battery-fires-flight/ 

https://stopthesethings.com/2021/09/17/tesla-terror-lithium-battery-bombs-exploding-in-toxic-fireballs-that-burn-for-days/ 

Scott R. Ellis
1 month ago

Lithium battery “fires” are not fires at all but rather runaway chemical reactions. I don’t know what that implies about the equipment necessary to stop that reaction, but then again, I’m not the one trying to answer the question in a national column. I’d be very curious as to what some more research turned up.

Jeremy
1 month ago
Reply to  Scott R. Ellis

You’re correct that the *cause* of a Lithium battery fire is a runaway chemical reaction. But the *result* is often absolutely is a fire.

The runaway chemical reaction that occurs during a thermal runaway event causes the battery compoennts to break down. Battery components usually include chemicals with lots of hydrogen and oxygen atoms (Among other flammable gasses). When they break down the hydrogen and oxygen atoms break free into separate molecules. Thermal runaway also releases a lot of heat, as these reactions are exothermic. So you have hydrogen, oxygen, high levels of heat as well as other flamable gasses and materials… which is what leads to the fire and/or explosion.

The reason why LiFePO4 is typically used for RV batteries is because the iron component in LFP forms a much stronger bond with the oxygen atoms. This stronger bond means the battery must reach much higher temperatures before thermal runaway occurs, and even then the amount of flammable gasses released is low