JRP3
Hyperactive Member
Have you seen side impact videos? If the Volt pack in the middle tunnel of the vehicle is compromised I don't see how a Tesla pack on the edges of a vehicle would not be.
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NHTSA and lithium ion batteries
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Nice video. The view from atop (Youtube, 0:17, crash cam frame #170) shows that the pole intrudes the vehicle by ~30in. For a model S, that would be ~15in into the frame and another 15in into the pack IF the car deforms the same way - which I doubt. You cannot compare the rigid structure of the pack with frame and body panels in a car floor to judge the intrusion depth.
stopcrazypp
Well-Known Member
I think it's more instructive to look at the Leaf side pole (as it uses a very similar floor mounted battery design):
Volt side poles for reference:
Another ABG commenter mentioned that the Leaf's side pole impact (see :20-:24) showed the top of the car tilting toward the pole, while the Volt's side pole impacts shows it being fairly level to the ground. The tilt is supposedly evidence that the floorpan held up better in the Leaf.
You also have to keep in mind the Volt's battery pack has a more unconventional T shape (not a true central tunnel like in the Fisker Karma), which may not distribute the stresses of a side impact as well as the floor mounted design like in the Leaf, iMIEV, Smart ed, Coda, and Model S. Basically the two handles on the T have a risk of bending in an impact, while a flat rectangular pack will likely distribute forces more evenly.
Plus the Volt's pack enclosure is plastic and isn't reinforced like the Leaf's pack (and likely Tesla's pack).
ABG reports they'll be adding more reinforcements to address the issue:
http://green.autoblog.com/2011/12/07/chevy-volt-battery-fix-may-cost-1-000-will-hang-on-to-top-iihs/
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Whoa. If the battery is the single most expensive component in a BEV at a third of the car's cost, this is a big call. Given that completely draining a battery signs it's death warrant is there no other protocol that can be implemented? Breakers? A non-battery-lethal minimal left remaining charge? Crash accelerometers ?
If a shopping cart hits a BEV in a parking lot and it leads to a $30,000 battery replacement that kind of news will hurt the EV movement too.
JRP3
Hyperactive Member
Since a single shorted cell can potentially start a fire breakers and such won't do much, other than lower the overall potential of the pack. I think in a severe crash which means the car is obviously totaled, such as these side impact events, draining a pack is reasonable if removal and inspection is not possible in a short time span. First you move the vehicle away from anything else, then take it from there. Don't park it with a full pack near a bunch of other vehicles, or put a damaged pack in a wooden structure 
Of course. The question here is at what level of even visible damage gets that decision made? Does a slight coolant drip have liability fearing, facility/inventory concerns have a impound yard owner sucking your car's value to half?
JRP3
Hyperactive Member
The question is how "empty" do they drain the pack? If they are using a constant current load the voltage will sag during the discharge but even when "empty" the voltage would spring back up when the load is off. Unless they taper the load or allow it to sit shorted for a while it may not be ruined. I'd like to see quick pack removal and inspection before a full drain, but it will have to be a judgement call I guess.
An Emergency responders access point to plug in a constant load device to be designed?
WhiteKnight
_____ P85 #549 _____ Sig Red / Sig White
The Good News :: Elon Musk said that the battery pack on the Model S would do great on the side impact tests illustrated because intrusion would be much lower (for the reasons stated)
The Bad News :: If you get into one of these type of crashes the battery pack is probably totaled which means the car is totaled.
The Bad News :: If you get into one of these type of crashes the battery pack is probably totaled which means the car is totaled.
stopcrazypp
Well-Known Member
I'm pretty sure any car in this type of collision (side pole) would be totaled regardless of the existence of a battery pack in the car. Once an impact deforms the crash structure in any way (every side pole crash I have seen so far deforms the frame of the car in some significant way), I don't think it is possible to repair it and have it still function the same way in another accident.
I'm even less worried about the standard side impact test (the one that simulates a car). Even in the Volt's case, the floor pan didn't seem like it deformed at all. The B-pillar seemed to have taken most of the hit.
Mycroft
Life happens
I think the most dangerous accident is a side impact by an SUV. The bumper is so high, it would only be the doors and B-pillar that would keep it from entering the compartment.
How about lithium phosphate batteries. This video seems pretty convincing.
http://www.youtube.com/watch?v=O8R0ig0J4wk&feature=youtube_gdata_player
http://www.youtube.com/watch?v=O8R0ig0J4wk&feature=youtube_gdata_player
JRP3
Hyperactive Member
Todd Burch
14-Year Member
These side pole tests are pretty severe. 20-30mph does not seem like much until you consider that the pole that's hit really doesn't move much at all.
Insurance companies would total all of these cars, but to Lloyd/VFX's points, I think a crash in which the car is salvageable or repairable would either have little damage to the pack or the damage would be small enough that the pack could be inspected or safely removed. In those cases, most of the battery cells would still be good, so I'd imagine that replacement costs would be considerably less than $30k.
Regardless, I'm sure the anti-EV FUD movement will make some of these arguments that small accidents require enormously expensive battery replacements.
Insurance companies would total all of these cars, but to Lloyd/VFX's points, I think a crash in which the car is salvageable or repairable would either have little damage to the pack or the damage would be small enough that the pack could be inspected or safely removed. In those cases, most of the battery cells would still be good, so I'd imagine that replacement costs would be considerably less than $30k.
Regardless, I'm sure the anti-EV FUD movement will make some of these arguments that small accidents require enormously expensive battery replacements.
JRP3
Hyperactive Member
Oh yeah, I've already been arguing with someone on Peak Oil who kept trying to say the Volt was totaled and caught fire from a 20 mph "fender bender". A few videos settled that argument.
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