Need some time to peruse
Thanks ill check this out over the weekend
OP should change title to better explain the specific topic
That was definitely interesting, especially the "hiding in the open" backup door release inside.
And the conclusion to the question of "how to open the trunk" - a button.
Well, we now know that the M3 shares the 400V HV design with the MS 85kWh+ versions. (Models 60, 70, 75 have 350V HV systems.)
It sounds like First Responders now need to bring with them their own 12V supply in case they need to open up Model 3 frunk. (Model S and X have mechanical means to open their frunks).
“Safe stabilization points for a Model 3 resting on its side“. Page 24
I find this a bit confusing. Thoughts?
Also the lift point areas seem to be “small”.
The good news is, it appears that thieves cannot just pop a 12V source to those wires in the front bumper to get in. (Assuming, of course, that the 12V battery in the M3 isn't dead.)
@Tâm As long as the first responders aren't coming on foot, they'll have access to a 12V battery... Or are you imagining their trucks / vehicles don't have one?
First responders have other, less subtle ways to open the frunk if they don't have a ready 12V source.
I perused the doc. :)
It's not clear what the battery voltage is. A good guess is the long range is 400V, and the short range is 350V. If you look at the Model S Emergency responder's manual, it also says "400V" with no mention of the 350V pack in the 40/60/70/75. Tesla is just stating the maximum voltage as safety information, and some models have lower voltages.
Did anyone notice the inside electronic door release for the front doors (page 27)? That's sort of cool. A manual release is also on the door and easy to use.
If you look at most uni-body cars the official lifting points are about the same. Normally there is only a small spot along the pinch weld that is the actual lift point.
The side stabilization points I think it is just a bad way to show it. It would be better to show the side of the car instead of the underside. I think they mean anywhere around the passenger cage the high strength steel can be used.
Why change the voltage? 96S46P for long-range, 96S31P for standard range. Same voltage, same number of bricks, only the maximum charge/discharge current changes.
Thx so the side stabilization points can be used as lift point?
@Frank99 - Dig a bit more digging on the battery voltage. It appears the Model 3 Long range uses a 350V battery, based on the Tesla EPA filings. As you noted, both battery sizes are likely the same voltage - my error thinking they may be different.
Note that the maximum charging voltage will be above 350V, so the manual showing a 400V number makes sense.
Let's see what this document on the Model 3 (https://www3.epa.gov/otaq/datafiles/CSI-HTSLV00.0L13.PDF) tells us:
Total Voltage of battery packs: 350 (p.2)
Average System Voltage: 351 (p. 6,7)
Now let's look at a battery pack that we know something about, Jason Hughes P100D pack:http://skie.net/skynet/projects/tesla/view_post/20_Pics+and+Info:+Inside...
It's a 96S86P pack of 18650's. What do the EPA docs say about it?https://www3.epa.gov/otaq/datafiles/CSI-HTSLV00.0L2S.PDF (starting on p. 8)
Total Voltage of battery packs: 400 (p. 3)
Average System Voltage: 350 (p. 10, 12)
400V / 96S = 4.17 volts/cell, very close to the industry-standard "Fully Charged" state for a LiIon battery of 4.2V.
350V / 96S = 3.65 volts/cell, which is almost exactly the industry-standard nominal, half-charged state for a loaded LiIon battery of 3.6-3.7V / cell.http://batteryuniversity.com/learn/article/confusion_with_voltages
So what differences do we see between the P100D and Model 3 packs?
Total Voltage: 350 v. 400. If the Model 3 pack were 350 V, that would imply 84 cells in series.
Average System Voltage: 351. Well, here we match the values for the P100D, implying 96 cells in series.
So, which number do we believe?
There are a lot of calculations that have been done showing that you need around 4416 2170 cells to get the kwh rating of the Model 3 pack, taking into account the volume differences between an 18650 and 2170. That means you either have a 350V, 84S52P pack, or a 400V, 96S46P pack. Assuming that the batteries pack the same, the two configurations would have the same volume, and fit in the same battery pack. If you need the same number of cells, and they go in the same volume pack, why would you change from the 400V system that your engineers are extremely familiar with to a 350V one? I'm going with the 400V pack. I'm also going to suggest that perhaps the Model 3 pack voltage was rated at nominal voltage of 3.65, rather than the fully-charged voltage of 4.2 (3.65 * 96 = 350.4V), though why Tesla would change that I don't know.
Do we even know which flavor of M3 the EPA documents linked above is for? (LR vs Standard.)
Page 1 of 12 shows near the bottom...
Mfr Test Group Comments: MY2017 certification for Model 3 Long Range carline.
garyjtate Probably not. While the stabilization points are likely strong enough to support the car trying to lift the car without damaging paint may be an issue. If the car is on its side and the first responders are trying to make sure it doesn't fall over they are not concerned about scratching the paint.
@garyjtate - yes please change the title - this is a useful document for any owner to go through.
I particularly like the photo of the Model 3 submerged in water.....some good gravity action going on there!
@Frank99 - Good analysis, but "why would you change from the 400V system that your engineers are extremely familiar with to a 350V one?"
Tesla is very familiar with 350V systems as all the 40/60/70/75 models all use a 350 v battery system, with the 350V systems designed and built since 2012 (with sales starting in Jan-2013). There are a lot of reasons to pick one configuration (400V vs 350V), and I don't know all of them. One reason to use a lower voltage means fewer cells in series, which may improve pack reliability slightly.
To me, it seems like 350V is a bit more likely due to the charging speed in kWh that seems a bit lower than the Model S 350V models. The Model 3 long-range charging miles-per-time is similar to the 400V models due to the Model 3's higher efficiency. My rough calculations has the Model 3 max charge rate of 88 kWh + maybe 4-5 kWh for waste heat. So the charging is around 93 kWh at a Supercharger (in the band where it can accept maximum power). The 350 V S75 can charge at 105 kWh, and the 400V S100 can charge at 120 kWh.
Now this is far from an accurate way to access the pack voltage. Clearly Tesla could use a 400V pack and use less current to charge at 93 kWh. So I'm hedging my bets - could be 350v, but could be 400V. We'll need a real confirmation by looking at the battery pack label and or perhaps Tesla stating what the real pack voltage is.
Maybe the 400V figure in the Tesla document should have said "up to 400V." :-)