Interesting model 3 info..
"Wiring:
"Mostly CAN with a touch of Ethernet (including BroadR-Reach single pair)."
Wiring reduced by having 3 body controllers instead of 1
*No fuses* in Model 3. All solid state virtual fuses. You don't actualy blow anything, you just trigger a software shutoff of the power until you reset the "fuse".
Display:
"Connected by a 2 twisted pair system called FPD link III. There is a 4-pin Fakra HSD connector on the ICE (computer) module behind the glovebox area that can be easily accessed"
Suspension:
Top suspension arm FRP, curiously enough.
Massive front stabilizer
MCU/ECU (computers, incl. autopilot):
Liquid cooled by the main glycol loop
Seat heaters:
"Rear seats do indeed have heaters and they are connected. Just no way in the GUI as yet to enable them."
Drive unit:
"The drive unit contains the Inverter, Switched-Reluctance motor, a gear-reduction, and a differential to split the torque between the 2 wheels."
"The RWD has a higher capacity inverter than the AWD. (800A vs 500A) I don't know if there will be a "P" version yet, but maybe that one would retain the 800A in the rear and add a 500A in front."
Front motor:
There's a giant hollow already just waiting for it. "Cavernous space. You could put a small child in here." Note for if you need a smuggling compartment...
Pack:
" I can tell you the voltage ranges haven't changed too much. BMS considers 100% SoC at 4.2v per cell but the bottom changed slightly; it's now 2.85v/cell for 0% SoC, whereas on S/X it was 2.5v/cell. Note that Tesla advises owners not to charge above 90% daily unless really needed, so that puts the top at around 4.1v/cell. There is also a bottom reserve of 3.5kWh that you can't touch."
4426 2170s, 96S46P arrangement, 4x modules
76kWh actual, 74kWh nominal. Possibly only 72.5 kWh usable due to the 3.5kWh "bottom reserve".
Max charge 192A**, max discharge 1200A (E
this must be AC charging, as that works out to too low for DC (47-78kW). Max discharge equates to 294-482kW / 392-646 max theoretical HP from the pack)
Min bus voltage 245V, max bus voltage 402V
Max regen 46,9kW, max discharge 370kW
Cooling:
Mounted on sizeable rubber gaskets and with a lot of acoustic foam, to keep it quiet.
Weights added to the cooling fan to ensure that it's properly balanced.
12V battery:
45 Ah. Not sealed.
Heat exchanger:
"It's a plate stack type on top of the drive unit. Looks similar to the one I showed in the 1st video where the glycol is chilled by the A/C refrigerant. "
"Yes, and not only that, but if it is super cold and they actually need to add heat (the motor/inverter is super efficient, so not much waste available), they purposely run the inverter in an inefficient mode to generate excessive waste heat to heat the pack. S/X had a s***ty electric battery heater in the glycol loop and these seem to be very unreliable. So on 3 they basically did it with software!"
Build quality and engineering:
"I've taken apart hundreds of cars so far, and I find the 3 to be well put together and a lot of thoughtful engineering throughout. Particularly impressed by the high levels of integration as compared to S/X. Also going to a electric pump and filter on the DU means they want it to last a long time. Really, the only maintenance most owners will need to perform is adding windshield washer fluid and replacing tires. Maybe a 12v battery every 5 years. Brake pads should do 100k unless you do a lot of aggressive stops."
"I think you must be referring to Sandy Munro. He had a lot to say about the fit/finish and went on and on about how the first responders can't get to the cut loop. First off, none of the fit/finish issues exist on recent the cars I've investigated, and secondly, Sandy's focus on the cut loop is silly. In any accident that would need first responders to cut into the car, the HV system has already been totally disabled by the RCM (Airbag Computer). Anything that matters seems to be really good. I welcome more objective analysis though!"
General safety:
"The RCM (Airbag ECU) blows the HV pyrotechnic disconnect in the HV pack as soon as there is an accident. Easy to safe the HV system by unplugging one low-voltage connector."
"The HV system is totally isolated from the chassis, and if the BMS detects that the isolation has been compromised, (due to a short from chassis to any part of the HV system) it will open the contactors."
"The fire vents relieve any pressure inside the hermetic pack enclosure, and if there are any hot gases, the deflectors redirect them to a safe place. There is a cabin filter, but it's inside, so a post filter, not a pre-filter like the S/X have."
"There is a lot of redundancy in critical systems. I've seen it in the BMS, Brakes, Power steering Rack, CAN buses, and Power distribution (no fuses). I haven't had the drive unit apart yet, but I expect it to have some redundancy, or at least built with fault tolerance in mind."
Power steering = 2 separate controllers; one can fail and you still have power steering.
Crash energy absorption structure is unboltable. If the car is in a crash, you can remove it and install a new one.
Automatic water vent if the pack somehow gets flooded.
From another user, about Ingineerix who took the car apart, in comparison to a person who posted a different teardown:
"I don't know what qualified that person to assess the quality of engineering, but I know Ingineerix personally and have never met anyone with a higher level of engineering skill and knowledge.""
