2022 Toyota Rav4 Hybrid Rear Battery Explosion – "I Pull Into A Gas Station And Hear A Pop Come From The Back Of The Car and Then Flames Start Erupting"

It may be a rare occurrence in the Rav4 Hybrid, but according to a recent social media post, it recently happened to a Rav4 owner who pulled into a gas station and heard a pop in the rear of his car followed by flames.

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A search online for the answer to the OP's question of whether anyone has heard of this happening in their Rav4 shows that, if anything, it is a rare experience and one not expected by any means.

However, one post comment points out that it is not impossible:

I came close to this happening, but it didn't happen. I kept some soup-based takeout on top of that area. Somehow, it fell and spilled into the nooks and crannies. Good thing I didn't have to travel too far.

Took it apart to clean it up, and the liquid almost made the negative and positive terminal connect. It was a mess under there. Got lucky." ―revocer

WHAT CAN CAUSE A 12-VOLT CAR BATTERY TO EXPLODE

The post comment hints that an owner-caused battery accident can happen and begs (in my troubled mind) an important question about Toyota's decision for its 12-volt battery placement.

For one, I do not like having the 12-volt battery stored and hidden in the rear cargo area of my spouse's Toyota Rav4. “Out of sight, out of mind” is a concern because you no longer have the easy convenience of a quick visual check under the hood.

Furthermore, I take issue with the possibility of battery acid gases trapped in the battery cubby, which could have caused the "pop" and fire.

The Possible Causes Of A 12-volt Battery Explosion Are Numerous:

1. A malfunction in the battery management system―Overcharging can lead to excessive hydrogen gas buildup inside the battery, especially in flooded lead-acid batteries. In sealed batteries like AGM, pressure can build to dangerous levels if vents fail. A spark (from corroded terminals or nearby electronics) can ignite the gas, causing an explosion.
2. An Internal Short Circuit―A defect in the battery (e.g., separator breakdown) or severe physical damage can result in a sudden internal discharge and generate intense heat and pressure, leading to battery case rupture and/or explosion due to internal arcing.
3. Loose or Corroded Terminals―This can lead to a battery drain and intermittent electrical contact that can cause sparks, which will ignite leaking hydrogen gas.
4. External Short Circuit or Damaged Wiring―Pinched or frayed wiring, especially after an accident or rodent damage, can cause uncontrolled current flow that can superheat the battery and cause a fire.
5. Physical Damage―A collision impact or continual vibration can cause cracking of the battery case and/or internal electrical damage, resulting in electrical shorts or abnormal chemical reactions inside the battery.

Selected Useful Thread Comments

Several thread comments back up the above-listed possible causes of a 12-volt battery fire. The most useful of these include vehicle safety and what to do about the incident, aside from considering premature lawyering up.

For example:

Glad you're safe OP! This is wild. Never heard of this happening. It could have gone so much worse.

Even if you're out of warranty, I would push Toyota on this. While obviously rare, a catastrophic failure like this warrants investigation to understand the mechanism and failures that caused it.

I have a 2A:10BC extinguisher mounted in my trunk via a molle panel. There's small ones designed to mount under passenger seats. Those seem more popular and easier to tuck away. Only advice I would offer is buying in person. Sometimes Amazon ones show up DOA." ―MichaelP09

Repair it but also investigate why it happened." ―motorcycle_girl

I would involve corporate and bypass the dealership for an investigation. While I'm no engineer, presumably, there are a lot of redundancies in preventing the 12v from catching fire. They all failed here; there was a vehicle fire, and only luck, along with your quick actions, prevented a more serious incident. So, I would be adamant in knowing how it occurred... Was it a rare failure of the battery? Was it wiring? Manufacturing defect? I would not expect any compensation, but like, what the hell caused it." ―MichaelP09

Be Safe, Be Smart

While 12V battery explosions can happen, they're exceedingly rare in modern hybrids, especially when using a sealed AGM battery and maintaining it properly. If you observe signs of swelling, strong odors, or electrical irregularities, have the battery tested or replaced immediately.

For more about maintaining your car's 12-volt battery, here is how to do it with this "Car Battery Maintenance, Testing, and Replacement Ultimate Guide."

And, just in case you are wondering what you can do with your Rav4 Hybrid battery, here is some useful advice and a warning about "Toyota Hybrid Battery Tests You Can Do and Those You Should Not Attempt."

Have you ever had an incident with your Toyota Rav4 12-volt battery? If so, tell us what occurred to the best of your knowledge in the comments section below.

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Timothy Boyer is an automotive reporter based in Cincinnati who currently researches and works on restoring older vehicles with engine modifications for improved performance. He also reports on modern cars (including EVs) with a focus on DIY mechanics, buying and using tools, and other related topical automotive repair news. Follow Tim on Twitter at @TimBoyerWrites as well as on Facebook and his automotive blog "Zen and the Art of DIY Car Repair" for useful daily news and topics related to new and used cars and trucks.

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