A mile of extra wire

Chicago-E

Well-Known Member
First Name
Brad
Joined
Dec 9, 2021
Threads
7
Messages
153
Reaction score
194
Location
Chicago
Vehicles
2021 GTPE Iconic Silver, 2021 GTPE Space White
Occupation
Generator Technician
Country flag
Let me try to break down each of his claims:



Yes it could be reduced with greater use of CAN bus, but I don't think it's that excessive now. That would be the theoretical maximum savings. All of the modules and body features need to be connected. The legacy modules used would need to be hooked up like they are now. Moving to a completely integrated CPU that controls all functions like Tesla is probably in the future, but there is a high engineering and time cost to get there. Purpose-built EV modules will come that will simply things. As has been said, the engineers had to take existing off-the-shelf modules used in other vehicles and make them work together in order to save time. As a result the Mach-E has a lot of modules that are coordinated to work together in some unconventional ways.



In theory that sounds like the maximum weight savings from eliminating the 1.6 km of wire, which won't have that big of an impact on range. The copper cost would likely comprise most of the $300. But I wonder why he said "battery" instead of "vehicle"? Perhaps he's referring to all the the BMS wiring in the pack. Each cell has a wire to the BECM (94x) for monitoring and balancing, a dozen wires to the HVBJB for controls, plus ten thermistors. As a result the BECM has about 140 wires going to it. Rather than being centralized with individual wires, the design could be decentralized to be a circuit board on each individual cell module that handles all those functions, and communicates back to the main BECM with a LIN bus. That could eliminate about 120 wires. Tesla uses a decentralized BMS like this in their packs.



This one is difficult to decipher. He must be taking about regenerative braking. The Mach-E seems to top out around 100 kW of regenerative braking for a very short time, which is a decent amount (Model Y is 85 kW I think, but the pack is proportionally smaller). But I personally think he's talking more about the issues seen with long-duration regen going down hills causing the motor inverters and battery pack to overheat. When he says battery size, I actually think he's referring to the busbar size in the battery pack or the amperage limits on the cells themselves. I've written about this previously, but it's my opinion that the busbars and connections were designed too small inside the pack.

The busbars should have been made thicker (5mm instead of 3 mm) or wider to handle the peak current demands better without overheating. They are big enough if you are driving a constant speed on flat terrain, but lots of acceleration or going up mountains can easily overheat things. The internals just weren't made robust enough. It's also my view that the pack design predates the decision to make it a performance oriented vehicle, rather I think the pack was designed for a "compliance car" which would have limited acceleration (possibly RWD only). The creation of the GT models with dual large motors really put demands on the pack it wasn't ever designed for, hence the 5 second rule. The thin busbar also puts more stress on the high voltage contactors in the HVBJB, making them more likely to fail due to insufficient heat sinking.

In summary, there are certainly greater efficiencies that can be made with the Mach-E's design. But I think the savings numbers he's giving to investors are absolutely top end. I don't think he will be able to save as much as he tells investors without sacrificing the quality or features of the product further. The focus should be on increasing simplicity AND quality because the warranty costs are astronomical.
300 per battery at 50000 units is 15mil. not chump change. all those inefficiencies add up to big dollars. I expect things to be better with the 2nd gen and plan on grabbing one when they are released.
Sponsored

 

Chicago-E

Well-Known Member
First Name
Brad
Joined
Dec 9, 2021
Threads
7
Messages
153
Reaction score
194
Location
Chicago
Vehicles
2021 GTPE Iconic Silver, 2021 GTPE Space White
Occupation
Generator Technician
Country flag
There we are thanks!

I an a noob so forgive me.

But while on one of those videos I watched the one where they showed the evolution and changes of the model Y rear unibody.

That is what sets Tesla apart imo, no other company is showing that agility
yet some how Tesla lack the ability to produce new models in reasonable time frames. model 3 is 10yrs old although it has under the hood changes. I see this as a major hurtle for Tesla. their design is getting boring. They will eventually run out of buyers. when is TBD.
 

mburtsvt

Well-Known Member
First Name
Michael
Joined
Dec 27, 2020
Threads
26
Messages
530
Reaction score
743
Location
California
Vehicles
Just 1 Rapid Red Mach-E
Occupation
Retired
Country flag
This is the most interesting part to me. I wonder what exactly that means, because I don't see a direct correlation between battery size (capacity?) vs braking.
Weight. What it takes to stop a 4000 pound small car.
 

RedOctobrrr

Well-Known Member
Joined
Nov 29, 2022
Threads
2
Messages
206
Reaction score
205
Location
Chicago
Vehicles
'23 Mach E Select AWD
Country flag
yet some how Tesla lack the ability to produce new models in reasonable time frames. model 3 is 10yrs old although it has under the hood changes. I see this as a major hurtle for Tesla. their design is getting boring. They will eventually run out of buyers. when is TBD.
I'll assume you mean the Model S? Because the Model 3 just turned 5½.

"the first production vehicle rolling off the assembly line on July 7, 2017"
 

Chicago-E

Well-Known Member
First Name
Brad
Joined
Dec 9, 2021
Threads
7
Messages
153
Reaction score
194
Location
Chicago
Vehicles
2021 GTPE Iconic Silver, 2021 GTPE Space White
Occupation
Generator Technician
Country flag
I'll assume you mean the Model S? Because the Model 3 just turned 5½.

"the first production vehicle rolling off the assembly line on July 7, 2017"
yup meant the model S, but as you noted model3 is also hitting that been around for a long time look too. but I understand there is supposed to be an update coming soon to that
 


Xadion

Well-Known Member
Joined
Jul 26, 2022
Threads
3
Messages
220
Reaction score
146
Location
USA
Vehicles
2022 Mach-E Premium RWD SR - Plat Graphite
Country flag
Model S has turned into their up up market car if you look at its price and interior changes and updates

The X outsells it because its generally the same or less, a big jump from Y or 3 and still stupid fast, while the S can get faster even.

while exterior has been the same the S did get refinements and you can see a difference between a old and new

As for generational change, the skeletal and other stuff is more of a change than some tradional cars get in a generation refresh

As for looks, once the market demands it they will do it... But even in a world of fresh competitors, teslas sell
 

abfoot7818

Member
First Name
Brad
Joined
Oct 25, 2022
Threads
0
Messages
24
Reaction score
8
Location
Washington D.C. Metro Area
Vehicles
2018 Ford Expedition Max FX4, 2014 C-Max PHEV
Country flag
I have decided not to buy 1st generation EVs any longer. The learning curve is just too great.

Can't wait till there's more EVs to choose from. hopefully it'll bring down the cost. We need more competition.
apply this to EVERY Vehicle And not the generation BUT the first (and maybe 2nd) model year. IF you wait for a second generation and but the first model year of the second generation you will be making the very mistake you are trying to avoid.

Recently my 2018 Expedition (first model year of redesign) was in the shop for 3 months. It actually was first returned to me with the check engine light on. Then returned to me with the light coming on one hour after I picked it up. Then can back to me to break in three days, then to have A massive transmission failure with 8 passengers on the way to NYC on the day after Christmas. (It never has left me stranded) - just limping home with 5th and 9th gears only. Actually, here is the laundry list you didn’t ask for but to prove my point.

When we bought in brand new from the dealer a crank position sensor went bad before we got behind the wheel. Then the power mirrors intermittently tried to face the sky grinding and popping beyond range of motion. Then the front hubs started grinding (4x4)
partially engaged on the interstate due to a vacuum leak. Then ford wanted to reprogram the engine due to valve tingeing ticking then they wanted to replace the gears for the engine valve timing then they wanted to reprogram the transmission. Then the parking solenoid failed. Then the throttle body failed- this was the first non-warranty was not part of powertrain warranty - but my master tech warranty covered it with a $100 deductible. Then they replaced the whole transmission under warranty.

I am still a Ford fan BUT I will not buy a first model year of a redesign. (Waiting for my 2023 MME driving a 2014 PHEV C-max) our Expedition is parked unless we have more than 5 passengers.
 

eleven24

Well-Known Member
First Name
Rob
Joined
Feb 1, 2023
Threads
14
Messages
333
Reaction score
610
Location
Doylestown, PA
Vehicles
2023 MME GT
Country flag
Sandy Munro does a great breakdown of this on his YouTube channel, specifically when it comes to the HVAC system in each car. Model Y has one hose and the Mach-e has a table full of hoses, all which add weight and reduce the EV battery range.

In defense of Ford though, Tesla started with a clean slate and has just 5 vehicle models so they can focus on efficiency of build. Ford has to focus on the efficiency of reusable parts among their vast product line for their Ford dealer service departments
Sponsored

 
 




Top