Hybrid Crash Test
1 - 20 of 20 Posts
Joined
·
89 Posts
Lithium ion batteries have significantly higher energy density than lead acid batteries.
A typical lead-acid car battery might store 700 watt-hours (and is amazingly able to source 5 kilowatts of power for brief intervals).
The lithium ion batteries in the PacHy store 16,000 watt-hours and are able to source at least 85 kilowatts of power for sustained periods.
It is only recently that lithium-ion batteries have been made safe enough, first for use in consumer electronics, and then later in consumer transport. Consider that as recently as last year, a major manufacturer (Samsung) had to recall billions of dollars of devices because the lithium ion batteries were failing in use in a way that they weren't in testing.
Lithium ion battery safety is no joke. After a Tesla Model S caught fire 20 minutes after running over a trailer hitch on the freeway (a fire that was in no way dangerous to the occupants, who had been told to leave the car... by the car), Tesla added a 1/4 inch thick titanium plate to the bottom of the vehicle. The PacHy has higher ground clearance, but it also has no titanium armor under the battery.
I will also be very interested to follow the development of crash safety testing of large batteries.
A typical lead-acid car battery might store 700 watt-hours (and is amazingly able to source 5 kilowatts of power for brief intervals).
The lithium ion batteries in the PacHy store 16,000 watt-hours and are able to source at least 85 kilowatts of power for sustained periods.
It is only recently that lithium-ion batteries have been made safe enough, first for use in consumer electronics, and then later in consumer transport. Consider that as recently as last year, a major manufacturer (Samsung) had to recall billions of dollars of devices because the lithium ion batteries were failing in use in a way that they weren't in testing.
Lithium ion battery safety is no joke. After a Tesla Model S caught fire 20 minutes after running over a trailer hitch on the freeway (a fire that was in no way dangerous to the occupants, who had been told to leave the car... by the car), Tesla added a 1/4 inch thick titanium plate to the bottom of the vehicle. The PacHy has higher ground clearance, but it also has no titanium armor under the battery.
I will also be very interested to follow the development of crash safety testing of large batteries.
Joined
·
16 Posts
IMHO this thread is pathognomonic of the Big Oil propagated fear of batteries.
You have all seen the extensively chronicled Leaf and Tesla fires before. The picture is shaking, charred chassis etc. What is not mentioned is that before the entire battery pack rages on fire it takes up to 45 minutes, plenty of time for safe evacuation. Even in high speed impacts resulting in occupant death battery fires are not seen, read the press, eg the 140mph cumulative frontal crash between a drug addict and a doctor here in Columbus a few months ago, or the rear-ending result in the death of a woman recently also here in OH.
Also notice the recent Samsung tablet battery fires. All occured gradually, everyone had time to notice extreme heating for quite a while, no one got burned.
In Teslas battery fires are preceded by overheating, which is clearly displayed on the dash, then about 15min later a warning to leave the car, then it takes quite a while for a fire to start.
You will not find one report of instant fire on high speed impact like gas tank vehicles in electrics.
I am not making this up, you can search teslamotorsclub.com.
So, rest assured, if it a liquid-cooled lithium battery, that should be your last worry.
I'd be more worried about keeping the fuel tank full, at about 1/4 full in 100deg. weather the fumes are just right to where it will explode on direct impact.
You have all seen the extensively chronicled Leaf and Tesla fires before. The picture is shaking, charred chassis etc. What is not mentioned is that before the entire battery pack rages on fire it takes up to 45 minutes, plenty of time for safe evacuation. Even in high speed impacts resulting in occupant death battery fires are not seen, read the press, eg the 140mph cumulative frontal crash between a drug addict and a doctor here in Columbus a few months ago, or the rear-ending result in the death of a woman recently also here in OH.
Also notice the recent Samsung tablet battery fires. All occured gradually, everyone had time to notice extreme heating for quite a while, no one got burned.
In Teslas battery fires are preceded by overheating, which is clearly displayed on the dash, then about 15min later a warning to leave the car, then it takes quite a while for a fire to start.
You will not find one report of instant fire on high speed impact like gas tank vehicles in electrics.
I am not making this up, you can search teslamotorsclub.com.
So, rest assured, if it a liquid-cooled lithium battery, that should be your last worry.
I'd be more worried about keeping the fuel tank full, at about 1/4 full in 100deg. weather the fumes are just right to where it will explode on direct impact.
Joined
·
288 Posts
There have been other fires caused by Lithium ion batteries in the transportation industry. See: https://en.wikipedia.org/wiki/Boeing_787_Dreamliner_battery_problems
No it isn't.
I'm very well informed when it comes to EV's. I've been a daily reader of greencarreports for years so I'm aware of the propaganda you speak of, but I'm a also a father and I don't exactly trust Chrysler. The batteries sit directly below the 2nd row seats in a compartment that is originally designed for storing folded seats. I'd like to see crash tests before i even consider purchasing.
Lithium Ion batteries can explode and erupt in flames if punctured. I'd like to see if Chrysler put any thought into protecting the occupants if that were to occur. This isn't Tesla we're talking about here...
Joined
·
282 Posts
That's true, Boeing had some issues with the Dreamliner but keep in mind that aviation is far more conservative (and rightfully so!) when it comes to new technology. They use an abundance of caution, which isn't a bad thing and I totally agree with the approach as it applies to aviation, but it can be overkill sometimes - especially if those designs are then extrapolated to other industries that don't need to be at that extreme level of caution.
In the case of Boeing, the particular design for the 787 battery was not great. There's a fantastic quote from Elon Musk about the original design for the Li-ion batteries in the 787 but I can't find it, I think it was a tweet? Anyway, it was something to the tune of their design was a bad idea and SpaceX would never have even considered it. It was a fun dig at Boeing (with whom SpaceX competes).
I'm not saying that lithium ion batteries aren't volatile and shouldn't be treated with respect, only that when designed properly they are no worse (and sometimes even safer) than oil-based fuel sources. It's a modern engineering miracle that there aren't fires all the time at gas stations. Car companies go to great lengths to ensure fuel tanks don't explode. They keep them under vacuum, they ground them and ventilate them as needed, they use materials that won't contribute to an explosion, heck even the fuel tank itself if pretty amazing with how it deforms so extremely during a crash to absorb energy without rupturing. Amazing stuff.
But there's no reason to think the same can't be / isn't true for lithium-ion battery packs. Millions of people walk around all day every day with lithium-ion batteries in their pant pockets and don't even think twice about it (except maybe some unfortunate Samsung customers). Like pretty much anything the technology is safe when done properly, just like gasoline.
Joined
·
282 Posts
You raise valid points and I am also interested in seeing those results because Chrysler. If we find out horrible things it wouldn't be the first time a US car company put money in front of safety, but batteries don't generally go up in flames immediately when punctured like a big bucket of gasoline would - it's a much slower process. I'd have to think that nowadays though, they wouldn't be able to get away with some of the stuff they did in the past...right? Right??
To your point about design, they actually designed the Pacifica with electrification in mind so it's entirely possible and, hopefully, probable that they did factor in battery safety during a crash into the design.
Like you said though, it's Chrysler not Tesla so who knows...until we see test results.
Joined
·
566 Posts
I understand this is a concern, but I'm not aware of any instance where a battery erupted into flames as a result of any crash test, ever.
There was the instance of the Volt battery fire after NHTSA testing, but that was an unusual situation in which the fire started two weeks later, and they were unable to replicate it.
The Pacifica's battery is in a well-protected location in the vehicle. The gasoline Pacifica is an IIHS Top Safety Pick+. I think it's unlikely that the crash test would reveal any risk of fires attributable to the battery.
Most EV fire risks have made themselves known through operating experience, like the Tesla example, rather than crash tests. There have been no Pacifica Hybrid fire incidents to date. If this is a concern for you I suggest waiting until the Hybrid has been on the road for at least another year.
There was the instance of the Volt battery fire after NHTSA testing, but that was an unusual situation in which the fire started two weeks later, and they were unable to replicate it.
The Pacifica's battery is in a well-protected location in the vehicle. The gasoline Pacifica is an IIHS Top Safety Pick+. I think it's unlikely that the crash test would reveal any risk of fires attributable to the battery.
Most EV fire risks have made themselves known through operating experience, like the Tesla example, rather than crash tests. There have been no Pacifica Hybrid fire incidents to date. If this is a concern for you I suggest waiting until the Hybrid has been on the road for at least another year.
Joined
·
108 Posts
If I was worried about the crash-safety of the PacHy, my first concern would on how the add'l 600 lbs of batteries affects the structural integrity of the vehicle in a crash. My next worry of course would be how the" gas tank holds up in a crash - you don't want a puncture that leaks fuel, which could then be ignited by a spark or other flammable source - all auto makes have mitigated that risk now. Because the PacHy's hybrid battery is so large - relatively speaking - I do worry about it bursting into flames because of a cooling malfunction causing an overheating scenario - but there are indicators that would light up way before that happens. I am thankful the batteries are sourced from LG and not Samsung! What I don't worry about is the battery bursting into flames immediately upon a collision - even if the battery casing was somehow punctured. I happened to be have been unfortunate enough to be in a collision in a hybrid vehicle where the hybrid battery was compromised. The car was completely dead immediately afterward as the power source was cut, and I assume the same would occur in a severe collision with a PacHy. Could it burst into flames at some point after a collision - YES, but there is sufficient time to extricate everyone from the vehicle, even in a "jaws-of-life" scenario.
Joined
·
566 Posts
This may be because the Pacifica Hybrid hasn't been a priority for testing, since it's a relatively low-volume vehicle.
There have been no reports about post-crash fires.
Joined
·
1,548 Posts
Here's a document that may be of interest with respect to collisions in the PacHy...
https://www.nfpa.org/~/media/files/...rst-responder-guide--final-20170123.pdf?la=en
https://www.nfpa.org/~/media/files/...rst-responder-guide--final-20170123.pdf?la=en
Joined
·
566 Posts
My friend, somone is pulling your leg. Is this what you really think? Where did you get this idea? This is completely wrong. They designed a battery compartment in that space. It's not like they unbolted the seats and set the batteries in the old seat tub. Come on man.
Joined
·
2,266 Posts
Earlier in this thread there were some claims made that lithium batteries take a long time to catch fire. How is this recent incident explained?
https://www.nbcbayarea.com/news/local/Sig-Alert-Issued-After-Accident-Causes-Car-Fire-on-Hwy-101-477762763.html
https://www.nbcbayarea.com/news/local/Sig-Alert-Issued-After-Accident-Causes-Car-Fire-on-Hwy-101-477762763.html
Joined
·
122 Posts
Each year, 300-400 people die in vehicle fires, in conventional gasoline vehicles. The reference above is the first EV fire fatality I’ve heard of so far. Since EV makes up around 1% of vehicles sales, the track record is pretty good.
https://www.nfpa.org/News-and-Resea...tatistics/Vehicle-fires/Highway-vehicle-fires
https://www.nfpa.org/News-and-Resea...tatistics/Vehicle-fires/Highway-vehicle-fires
Joined
·
566 Posts
If the force of the crash is high enough to slice the vehicle completely in two, then the battery might catch fire quickly. There was another case where a stolen Model S was wrapped around a pole and broke into two pieces. There was a fire then, too.
I think we're talking about less extreme, survivable crashes, of the kind studied in crash tests.
By the time the Tesla caught fire, the driver was already out of the Tesla. He died from injuries from the crash not the fire, at the hospital. The media/haters make it seem like he died in the fire.
Joined
·
1,465 Posts
My 2 cents.
Our HV batteries are a combination of 96 cell packs in grouped modules. They are not tightly packed and have air space all around them with cooling and heating circuits through out.
For a battery to pop it needs to be punctured or deformed enough to squeeze the space from between the cell packs and crush them hard enough to short the material internally. Placed in the center of the vehicle makes this extremely tough to happen and have survivors since the cabin would have to be crushed to accomplish this.
Once you mount the battery box inside the compartment box it becomes extremely ridgid. And with shrinking the overall batterys size to down to a small physical footprint that fits under the second row seats it becomes more ridgid again. Then place that in the center of the vehicle - the risk diminishes rapidly.. because the rest of the car must crush first.. then the battery compartment..then the battery box itself. Unless mounting hardware fails inside and allows the cells to move freely inside the box, the force is absorbed and not transfered harmfully to the cells and is not more dangerous than a fuel tank.
Try this with a cardboard box, out it inside another cardboard box and step on it.. Its exceptionally more difficult to crush.
Fire is still possible of course, but the severity of an impact like this greatly increases the chance of fatality from the collision alone. And no car is safe from catching fire.
Heres a link to BMW i3 material. I've attached screen shots of the crush zones that require special attention. Note its within the frame rails and this battery is almost 1/3 of the total vehicle area.. and its only a 22kWh capacity. Ours fits under the 2nd row seats!
Index of /BMW I3
The pacifica is designed well and uses modern saftey equipment and materials such as HSS and alloys and does not deform easy. I remember reading somewhere they share the same chassis but the chassis was designed from the get go to be a hybrid and offer future ability to go all wheel drive but I cant find this reference any longer. I'll keep looking.
Edit: https://www.cargurus.com/Cars/2018-Chrysler-Pacifica-Hybrid-Overview-c27084
https://www.google.ca/amp/www.autom...minivan-debuts-at-2016-detroit-auto-show/amp/
I believe the chassis has proven itself and there is little to worry about.
Our HV batteries are a combination of 96 cell packs in grouped modules. They are not tightly packed and have air space all around them with cooling and heating circuits through out.
For a battery to pop it needs to be punctured or deformed enough to squeeze the space from between the cell packs and crush them hard enough to short the material internally. Placed in the center of the vehicle makes this extremely tough to happen and have survivors since the cabin would have to be crushed to accomplish this.
Once you mount the battery box inside the compartment box it becomes extremely ridgid. And with shrinking the overall batterys size to down to a small physical footprint that fits under the second row seats it becomes more ridgid again. Then place that in the center of the vehicle - the risk diminishes rapidly.. because the rest of the car must crush first.. then the battery compartment..then the battery box itself. Unless mounting hardware fails inside and allows the cells to move freely inside the box, the force is absorbed and not transfered harmfully to the cells and is not more dangerous than a fuel tank.
Try this with a cardboard box, out it inside another cardboard box and step on it.. Its exceptionally more difficult to crush.
Fire is still possible of course, but the severity of an impact like this greatly increases the chance of fatality from the collision alone. And no car is safe from catching fire.
Heres a link to BMW i3 material. I've attached screen shots of the crush zones that require special attention. Note its within the frame rails and this battery is almost 1/3 of the total vehicle area.. and its only a 22kWh capacity. Ours fits under the 2nd row seats!
Index of /BMW I3
The pacifica is designed well and uses modern saftey equipment and materials such as HSS and alloys and does not deform easy. I remember reading somewhere they share the same chassis but the chassis was designed from the get go to be a hybrid and offer future ability to go all wheel drive but I cant find this reference any longer. I'll keep looking.
Edit: https://www.cargurus.com/Cars/2018-Chrysler-Pacifica-Hybrid-Overview-c27084
https://www.google.ca/amp/www.autom...minivan-debuts-at-2016-detroit-auto-show/amp/
I believe the chassis has proven itself and there is little to worry about.
Attachments
Joined
·
2,266 Posts
Thanks for that information. The media stories did little to dispel the notion that the fire was the main cause of death.
1 - 20 of 20 Posts
