I’m quite pro-hybrid. They may seem overly complicated at first glance – you do have, essentially, two parallel drivetrains, after all – but the combustion drivetrain’s strengths and weaknesses dovetail so nicely with the strengths and weaknesses of the electric drivetrain. For a hybrid to work and deliver what it promises, like improved fuel economy and reduced emissions, both drivetrains need to work, which means the battery for the electrical drivetrain needs to be, you know, functional. This is obvious. What’s less obvious is how much of an Achilles’ heel many of these batteries have, and how vulnerable the batteries can be to expensive failures, especially if the hybrid owners have a dog.
I know this may sound strange – why should dog ownership affect something like hybrid battery longevity? It all comes down cooling. Not the dog’s cooling – they’re very skilled at panting to shed excess heat, I mean the battery cooling, which, in the case of many hybrids from Toyota, Lexus, Honda, Kia, and others, depends on air cooling through a set of vents dedicated to this purpose. If this vent gets blocked or clogged for any period of time, the battery can overheat to the point of failure, leaving the owner with what is effectively an underpowered combustion car that’s dragging around about 1,000 pounds of now useless hardware, and, of course, fuel economy and performance will suffer significantly.
If the battery does fail, it’s also an expensive repair; for example, a replacement battery for a Toyota Corolla Hybrid can range between $2,000 and $8,000. That’s not cheap.
So why am I singling out dog owners here? Because dog owners are likely to have covers on their rear seats to protect the seats from their sloppy, goofy, friendly furry friends, and those covers often block these crucial vents. Also, dog hair can clog these vents and their associated filters, leading to cooling issues that way as well.
I don’t think the crucial nature of these hybrid cooling vents are as well understood by owners as they should be, which is a big part of why I’m writing this. I have friends with dogs and hybrid that have had a seat cover that blocks these vents, and our own Bishop told me he was just in a Toyota hybrid Uber that had seat covers that blocked the hybrid battery cooling vents. A blanket under a baby seat, placed to protect the upholstery, could block these vents. Some reusable grocery bags that you keep in your rear footwells could block these vents. A thrown jacket could. There’s just so many, many ways to block these vents without even having to think about it too hard.
Some people are aware of the issue, of course, and actively try to find seat cover solutions that won’t potentially kill their battery, but plenty of other people have no idea what these vents are or how crucial it is to keep them unblocked. There are posts from people on forums where they’ve only discovered why their fuel economy has tanked after its too late and their battery could already be ruined:
In the case of that Highlander owner, the battery/hybrid system shut down to prevent more damage, which is better than total battery failure, but it’s still not great, by a long shot.
So, why is it like this? Objectively, placing a crucial vent in the area of the back seat feels like a terrible, unforgiving idea. Aside from dog-protecting seat covers, there are just so many ways those vents can be blocked. Packing for a long road trip with a friend? Who among us hasn’t used the rear seat area to store cargo or camping gear or whatever on a long trip. If you do that in your Highlander or RAV4 or Kia Nero or whatever, you could very easily block those vents quite effectively without even realizing it.
The reason the vents are inside the cabin at all is because the carmakers were trying to be smart: they know the battery wants to be about the same temperature as humans want to be, and they know the cabin of the car will already likely be either warmed or cooled by the HVAC system, so that’s ideal air to pull, temperature-wise.
The problem is that it seems like very little thought went into the positioning of these vents beyond that. They’re so easy to block, and the consequences for that blockage are so severe, it all feels like a very unforgiving design decision. Could these not have been placed, say, high on the B or C pillars, in places unlikely to be covered by bags or seat covers or dogs? They’d need more ducting to get to the underseat battery, sure, but it seems like a better place for these vents.
Also, how many hybrid owners know that often these vents have filters that require cleaning? I bet not enough.
To add an extra level of complication, on some cars, the vents are the designated place to blast water into in case of a battery fire:
…so a longer duct/path to the battery via a vent could be an issue for that, but I still think there has to be a better solution for these crucial vents.
Carmakers can’t expect owners – especially second or third or whatever owners – to know what these nondescript vents are and how crucial they are. Perhaps they should have warning stickers right on the vents warning that they should never be blocked? Or, ideally, the locations of these vents need to be rethought more completely. Low-set and right by the seat bottoms or backs are just areas that are far too likely to be blocked from airflow for entirely normal, commonplace reasons. It’s just bad design to require these areas to be perpetually unblocked and free for airflow.
I know it’s an engineering challenge, but this feels like a worthwhile one to solve. There must be ways to integrate these vents into the pillars or ceiling and get them away from where something as fundamental as gravity is conspiring to block airflow. I’d even take a simple warning light to tell the driver if the vent is blocked!
This is a design problem, not a user problem, but current hybrid owners are the ones who are at risk. If you have non-gearhead friends with hybrids, I think it’s worth pointing these vents out to them and at least making them aware of how important they are, before they leave a bag back there blocking a vent, or put on a seat cover or something like that over them. You could be saving your unwitting pals thousands of dollars, and keeping their dogs from getting the blame for an expensive repair.
Leave your dogs at home. And read the owner’s manual.
This is why all hybrids should be VW Beetles. You can never get any heat in those things!
When I got a Prius-C (Toyota Aqua, most underappreciated vehicle of the 21st century, fite me) the battery filter issue is one of the first things that came up in my search through owners’ forums. If the filter gets clogged and the battery overheats, it will throw a ‘HYBRID SYSTEM ERROR STOP VEHICLE IMMEDIATELY’ error. I got i a bunch of posts with people panicing that they’ll have to spend $3000 on new batteries/inverters only to come back with ‘oh yeah cleaning the filter fixed it’. It’s also the first thing other Prius-C owners warn me about.
Toyota is also extremely careful with the battery, so it it takes very little – like putting a duffel bag in front of the vent – to trigger the error.
I wish they’d warned me that the digital gas gauge is not fcking around, but that’s another story.
The Prius C is the best Prius. Now let’s not tell the whole internet
I’ll bite, what happened with the digital gas gage?
Well, I have to set this up by saying my last car was a completely analog car – a 93 Civic DX Hatch. The gas gauge on it and every other analog car I’ve driven has several gallons of ‘reserve capacity’ after the ‘E’ on the gas gauge.
So, I was expecting something similar with the Prius. I went for an impromptu long drive shortly after I got it, just to get used to the car. It didn’t have much gas, so I figured I’d run it down empty, fill it up, then run it down again to get a tank average. (Yes, it has a real time and trip MPG display, but that hadn’t quite clicked.) South of Portland, the fuel went down to one bar, then after a bit, started blinking. I figured ok, cool, when it’s really critical it will have zero bars, or turn red, or have some other ‘Hey bro, I’m not kidding’ alert. In my mind, there’s still 1-2 gallons of gas in the tank, because in every other car I’ve ever driven, that’s what ‘E’ means and I’m still one (blinking) bar away from ‘E’.
I miss the exit for a truck stop and figure I’ll catch the next one, then turn around; then the car’s engine starts stuttering and dies. The Prius-C only has about 2 miles of battery capacity at full, and I desperately try to nurse it on the shoulder to the next exit, but it dies in the middle of nowhere.
I do my best to push buttons and decipher warning lights, but nothing’s happening. Thankfully, I have the best tool a hooptie enthusiast can carry: a AAA card. I call for a tow and sit back and ruminate on my despair. This is a car I’ve just gotten from a dealership and it’s died on my first major run. The tow truck is over an hour out, so I’m parked with my emergency lights on marinating in gloom and angst like gothic hot dog.
After fifteen minutes, I get bored of channeling my teenage self and start with the bad ideas, like a grownup. Maybe the computer’s thrown an error code that needs to be cleared. I reset the error codes and try again. The engine sputters to life briefly then quits.
Staring at the displays in front of me, I get a dim lightbulb of inspiration and look up ‘prius c fuel gauge’; and yeah, I find out that the fuel gauge on a Prius not fcking around. It’s designed with a ruthless, almost Germanic literalness. Each bar is 0.95 gallons, there are ten bars, there is no more, there is no forgiveness, there is no salvation, there are no second chances, do not play chicken with the Prius fuel gauge.
I sheepishly call AAA back and ask them to send fuel help instead. The tow truck hasn’t even left yet.
A kind soul driving a Lyriq stops to offer help; a former Prius owner. We chat for a bit before he leaves. Yeah, the fuel gauge works like that. He had a 3rd gen, too. He winces at the mention of the 2zr. The Lyriq is pretty hecking amazing. I thank him for stopping and sink back into my shame.
The 12v battery is starting to run down to the point where the interior lights dim with each click of the hazard lights. I have enough time to make my second mistake: I keep googling. And just like every medical symptom you google is cancer, every car problem you have is catastrophic. There are people claiming ‘if you run out of gas and deplete the traction battery, it can’t charge, you have to take it to a toyota dealer who has to borrow a special charger, and there’s only one in each state…’
So I was in a state of new-car euphoria, fell into panic and depression, then was firmly on the border of ‘everything will be ok’ – and now I’ve checked in to the Massive Anxiety Hotel. Room service arrives in the form of the AAA gas guy. He puts two gallons in and – nothing. The car refuses to even try to turn over the gas engine. He has experience with Priuses because, you know, Portland, and we go through the code resetting process. Nothing. He puts a jump pack on the 12v. Nothing. He has me enter the secret Konami code that force starts the gas engine. No luck. We stare at it for a few minutes. The car remains as it was, aside from making a short click-click-click sound from somewhere under the dash. He puts away the gas can and buttons up the hood, then as he’s taking away his jump pack he says “Try it one more time.” With great pessimism, I do – and the engine comes back to life! The traction battery on the display has an orange ‘charging’ arrow pointing at it! Nothing is destroyed! Yipee!
So yeah, when I went looking for ‘Prius C problems’ before I bought it, I found out about the battery air filter, the first-year flaws in the headlight and taillight design, the weak door lock actuators, but not how to read the gas gauge.
People are awesome sometimes, I’m glad that AAA guy didn’t just give up after the gas.
Thanks for the story
The solution is to install massive side vents like it’s the late ’80s and everyone wants to pretend they’re a Testarossa.
Wow good information something I never knew to go along with the already too long list of other stuff I don’t know. I was thinking the pillars and zero cost if you just design the body with the vent holes. Then a removable panel to stuff a water hose on case of fire. Hey would it be safe to put water there with out a fire just to cool it off in hot areas. You know going over mountains towing something on a hot day pull up to the air and water island and just pour water in to lower the temperature. But then I was thinking hot air rises so would having these vents too high keep cold air from getting down to the battery? If so why not horizontal in frame cooling vents that have outside air vents and operate like a VW with an electric fan or turbo fan to increase air speed to cool faster? Or a cooler in the middle of the back seat to keep your cool items cool on a trip and the battery
Pretty much all hybrids have automatic climate control. Seems like there could be a temperature probe on the air intake, and the computer could compare the cabin temperature to the air inside the intake. Too big of a difference for too long, and a warning message pops up on the screen, instructing the driver what to check. Or, maybe it needs to measure airflow, not temperature. Not sure. But, it does seem like this could be fixed for a very, very minimal cost.
Yes, the computer knows all, as mentioned by others some do detect inadequate air flow, whether caused by an object or severely dirty filter (when present) and turn on some sort of warning long before any battery damage is done. Others, not so much.
More than anything this sounds like poor design.
Seriously. If “normal use” by a large portion of your customer base is risking a failure, it sounds like you need to design around that.
It would be more complicated ductwork, but why not just pull air through the cabin air filter. Maybe make the cabin air filter larger because of the now larger load on it.
As someone who has written and drawn things for car manuals that no one has ever read, my opinion is that people who don’t read manuals deserve catastrophic failures a bit more often.
However as a design engineer, and former product designer, I know that anything important should have a hi-viz warning label. No one will read it, obviously, but it really cuts down on the getting sued. Also if it’s that important maybe design it so an average user won’t use it wrong. So liquid cooled batteries it is.
Or a $300 brand/model specific seat cover with a screen protector for the vents with the directions on the inside saying this side in make sure you do not block air flow in front of vents or your car will be a paperweight
Sounds like the obvious solution is to build the batteries into the roof, and move the vent up there where it won’t be blocked until the vehicle is rolled.
The vents are right there because that’s where the battery is. You’d need a complicated duct system to pull air from somewhere else in the cabin.
Not saying it can’t be done but it’s a consideration. Warning labels might be better.
Electric radiator fan see it already exists
More importantly, who’s dog is that in the top shot?
Reminds me of my first dog who we suspect was a rat terrier mix, but the dog DNA people couldn’t even identify as a dog. We have decided he was a chupacabra (he was from Puerto Rico, so it is possible).
That dog was Abby, my sweet little tripod who died last year. https://www.theautopian.com/in-memory-of-my-dog-abby-a-very-sweet-little-three-legged-dummy-cold-start/
Goddamn. I missed that. Sorry about Abby.
The description of her temperament reminds me of my current dog Maggie, who literally would crawl inside me if she could.
I actually put her in a dog baby bjorn thing even though she was a bit outside the weight limits. She loved it. People look at you strangely with a 60 pound pitbull strapped to your belly, but she was proud as could be.
I can’t really do it that often (please see previous mention of her weight), but we’ll definitely do it again when my back recovers.
So she would wear your skin like an overcoat and enjoy a meal of your liver and fava beans and a nice Chianti?
Absolutely. I love and respect her for it.
She’s also a great big fat person in a small brown furry wrapper.
Paragraph 2: username checks out
Damn, I miss Abby! She was the sweetest dog niece.
This had me checking on the vent location for my Maverick, which actually doesn’t exist. The traction battery is liquid cooled so it doesn’t have a vent like this.
I did the same! Came to the same conclusion. It seems like a smart way to do it.
Didn’t we have this warning light discussion, like, today??
In my case, it would be blocked by McDonalds cheeseburger wrappers going fwap-fwap-fwap.
If I have to choose between dogs and hybrids, F hybrids.
Not directly about dogs at all. CLICKBAIT!!!!!!!!!!!!!!!!!!! 😛
(sorry, I had to)
Lots of people with no dogs use seat covers, too.
The good covers like Iggee and Coverking probably are compatible with the hybrid cooling shit
And other examples were mentioned but hey you have to use dogs to pull them in.
I saw this and had to text my dad ASAP, as he has covered back seats in his hybrid. Thanks, Torch!
I am sure all the Autopian staff warned their family and friends but The story didn’t mention if Bishop warned his Uber driver in a weird taxicab confession.
I’m shocked they compromised the passenger compartment. Seems like high risk of toxic exposure. I see they are designed as intake only, but are all failure modes covered?
It’s really only toxic if it ruptured. And you would KNOW if it violently ruptured.
I’m no expert, but don’t battery packs have vents ?
Sometimes but not always.
A couple of tear-down videos showed what would be analogous to freeze plugs in an engine block. Not continuously venting, but would activate if internal pressure is sufficient.
C pillar location for the vent is what I was thinking made sense. NVH issues were mentioned, but those should be total solvable.
Unfortunately, C pillars on many cars are already too fat and visually obstructing. But for preventing air vent obstruction, yes it’s a good place.
Mmm…nah. You just bought a complicated, expensive machine. Operate it correctly. If you can’t be bothered, there are consequences.
One one hand, I agree. On the other hand, car owners aren’t used to covering a vent (one that may be mostly hidden from view, even) causing catastophic damage.
I have a phone holder in my AC vent. When I snap my phone to it, the only damage is less airflow to the driver. The engine isn’t going to seize up over it.
Yeah, it’s a shit design.
I’m usually on the “RTFM” page, but when the manual is 89723 pages long and completely non-linear, broken up by warning boxes and other notes, then you can’t expect blurbs like this to not go unnoticed.
Either design something that isn’t easily blocked, put a warning sticker on it, or detect when it’s blocked and throw up an easily understood message.
The problem is so many people have no idea what moves their car. If I asked my mom right now “Mom, is your Accord a hybrid, does it have a CVT?” She’d probably say “Oh, I don’t know honey”.
The system that moves the car is not a consideration during purchase or ownership. A wrench shaped light comes on in the dash so they take it to the dealer. They enjoy a coffee and a donut, pay the bill and drive it home.
Wait, WHAT??? Doesn’t the hot air exhaust to the outside? If so, can’t they make the inlet tucked somewhere inside the body. Or does the heated air return to the cabin. That can’t be right. This whole thing is making me think to hard.
This. There should be some vent to the outside…
Well IMHO the battery is already outside but that means hot day hot battery a little AC never hurts.
The exhaust vent is to the outside of the vehicle, it’s the intake vent that’s inside the car that people are accidentally covering. The intake is in the cabin because on hot days it pulls in air cooled by the A/C which saves needing a separate cooling system for the battery
Huh, TIL, and my wife had a Highlander Hybrid for a few years. I certainly wasn’t aware of any filters that needed to be serviced.
Putting the vent at ear height might create NVH issues, but it seems like there should be some better solution.
Not just dog owners, but grandparents as well. Mine never have a car seat uncovered. Everything has some fluffy seat cover on it (which does feel nice).
“Grandpa, can we get ice cream?”
“We can now!”
Old people adding upholstery to cars needs to stop. It’s caused real damage to storefronts (Camrys and Avalons with ‘unintented acceleration’ because someone decided to stack cheap floormats on top of factory floormats to protect them) and now to the owners’ cars themselves.
If granny wants to add a crocheted cover to the tissue box on the rear deck, fine. Anything beyond that should fail annual safety inspections.
No, they’ll move the vents to the rear deck next.
Shhh! Just let it ride put one more Camr generation and we won’t have to worry about this anymore. The youngest Boomers are like three insurance payments from their kids taking the keys.
“In the case of that Highlander owner, the battery/hybrid system shut down to prevent more damage, which is better than total battery failure, but it’s still not great, by a long shot”
If the battery shuts down before permanent damage occurs and prevents permanent damage from occurring with the only penalty being MPG drops to whatever the ICE alone yields that’s really not so awful.
A better question is why doesn’t a warning light come on or a verbal warning played to let the driver know there is a problem BEFORE the battery shuts down?
Yes a simple battery temperature exceeds safe operated range pull over at next service station make sure cents in the back seat aren’t covered run it through the car wash select under spray option
And knowing Toyota, there’s a decent safety margin between “high but acceptable operating temp” and the temp where battery damage occurs. That warning could be set to trigger a couple degrees above the safe operating temp and the damaging temp.
I understand those words individually, but I have no idea what they mean in aggregate.
Stream of consciousness.
At least in a Prius, and I suspect other Toyotas, the error that comes on is a gigantic all-caps ‘HYBRID SYSTEM ERROR STOP DRIVING NOW’ message that completely replaces the information on the trip display. When I was researching buying one, I found a lot of people panicing because it sounds like a $5000 error code and not a ‘clean your filthy car’ message. It’s kind of too much of an error rather than too little of one.
“When I was researching buying one, I found a lot of people panicing because it sounds like a $5000 error code and not a ‘clean your filthy car’ message.”
Sounds like a good way to pick up a used Prius dirt cheap and *fix it* for nothing.
Or, with all the damn screens in cars these day, why does it seem like none of them are capable of actually telling you what the problem is. “Battery high temp, check filter.” or even walk me through a menu of the three or four most common failure modes an owner might be able to address.
But no, we’ll just say something generic like “BATTERY ERROR, STOP CAR, P14181274657”
Yeah, you’d think with the screens in cars having a searchable PDF of the owner’s manual (possibly with error code definitions) would be a fairly trivial addition.
Audi has their owners manual on the center screen which is handy but I am not sure how searchable it is. I am actually not sure if they come with a physical book because I bought mine CPO and it did not.
I’m not surprised somebody’s done it (I obviously haven’t driven everything out there). Not making it searchable would make it a frustratingly clunky implementation of a great idea…
I have only had the car about 5 months and traded in an A4 for a 4 yr newer A6 so there hasn’t been much of a learning curve. I may have to go explore it a bit just to see if it is actually useful.
Dog gone batteries.
Canines Are Ruff on Hybrids
Put the vent in the cowl, and you’ll never need to howl.
LOL
Sit!
Are the batteries DOG sized?
I’m not even sure it’s a design problem, really. It’s an education problem. Maybe we can add an indicator light to the dashboard to remind owners to clean the filter? And maybe one to let the driver know if the inlet is blocked? Drivers are REALLY good at knowing what the lights are for, right?
I’m with Torch calling it a design issue. Its in a place where a dropped drink can slosh down that opening, and some batteries warn of short circuits if that happens? I imagine at least one person has had their dog straight pee down that vent even.
My dogs would never pee there!
I did have a #2 situation in my Outback with one of my dogs. Thank goodness for that rubber cargo tray.
Maybe they wouldn’t pee but would the males jump it? If so would that clog the vents or cool of the battery. Heck would the pee cool the battery? We must think outside the litter box.
The vent is like three or four inches off the floor – dang, man, how much soda are you drinking? How big is your dog?
Still you got cargo issues. No cargo in the back seat cuts the versatile ability of the car