Luke42

Well-known member
Joined
Aug 10, 2020
Threads
0
Messages
852
Reaction score
1,596
Location
Illinois, USA
Vehicles
GMC Sierra Hybrid (2-Mode)
Country flag
Existing Superchargers don't need to be, do they? Correct me if I am wrong, but a 900v system would still be able to be charged by existing DC fast chargers without changing them.

Porsche Taycan has an 800v system and it can charge at most CCS chargers even if they don't support 800v.

I assume a 900v system (if true) would be driven by cost gains (at volume) and a potential increased charging speed would just be an added benefit.
You can put a bigass boost converter in the car if you need to bump the voltage up to 900V.

But it comes with a tradeoff: a bigass boost converter costs money, mass, and volume on every car.

It's much better to put a bigass boost converter offboard, if you can, where mass & volume don't matter so much.

 
Last edited:

fritter63

Well-known member
First Name
Mark
Joined
Jan 21, 2020
Threads
18
Messages
699
Reaction score
1,260
Location
Atascadero
Vehicles
2018 Model 3 LR, 2019 Model 3 SR+
Occupation
Software Engineer
Country flag
I will probably some flax for this, but on my EV Conversion one of my Tesla S modules had (4) 18650 cells fail in the same cell group. Rather than wasting a $1600 module I connected 4 matched 18650 cells in a parrallel group and connect that to to the bus plate that included the damaged cells. I approximated an appropriate fuse size. I has worked for 6 months now.
PLEASE tell us that you used duct tape and not bailing wire for this??? :cool:
 

TechOps

Well-known member
Joined
Apr 6, 2020
Threads
2
Messages
74
Reaction score
236
Location
Austin, TX
Vehicles
Model 3, Model Y, ex-Model S
Country flag
You can put a bigass boost converter in the car if you need to bump the voltage up to 900V.
lol, BABC .. also known as a step-up transformer.

I can think of two ways to retain backward compatibility with V1-V3 superchargers, and also allow 900V V4 superchargers:

Option 1. A 2:1 step-up transformer would boost incoming DC voltage from 450V to 900V on V1-V3. (As mentioned by Luke42, that would imply more weight, metal, and cost on-board the CT)

Option 2. They could have two sets of connection points for the battery pack toward the incoming DC charger, by simply changing how many battery strings are in series. Connections 1 would be at 900V and connections 2 would be at 450V. (I see this as much more likely due to the downsides of option 1 .. "the best part is no part.")

Option 3. Some other clever idea Tesla's electrical engineers come up with.

Everything beyond the battery pack could be at 900V, which would give the benefits mentioned by Elon, mainly a reduction in wire gauge and material weight.
 

LDRHAWKE

Well-known member
First Name
John
Joined
Dec 24, 2019
Threads
6
Messages
224
Reaction score
276
Location
Saint Augustine, Fl
Vehicles
Toyota FJ, GTS1000,FJR1300, Aprillia Scarabeo,
Occupation
Retired Engineer
Country flag
When describing voltage, current, and resistance, a common analogy is a water tank. In this analogy, charge is represented by the water amount, voltage is represented by the water pressure, and current is represented by the water flow. So for this analogy, remember:

  • Water = Charge
  • Pressure = Voltage
  • Flow = Current
Consider a water tank at a certain height above the ground. At the bottom of this tank there is a hose.



5113d1c3ce395fc87d000000.png



The pressure at the end of the hose can represent voltage. The water in the tank represents charge. The more water in the tank, the higher the charge, the more pressure is measured at the end of the hose.

We can think of this tank as a battery, a place where we store a certain amount of energy and then release it. If we drain our tank a certain amount, the pressure created at the end of the hose goes down. We can think of this as decreasing voltage, like when a flashlight gets dimmer as the batteries run down. There is also a decrease in the amount of water that will flow through the hose. Less pressure means less water is flowing, which brings us to current.
 


fritter63

Well-known member
First Name
Mark
Joined
Jan 21, 2020
Threads
18
Messages
699
Reaction score
1,260
Location
Atascadero
Vehicles
2018 Model 3 LR, 2019 Model 3 SR+
Occupation
Software Engineer
Country flag
When describing voltage, current, and resistance, a common analogy is a water tank.
Exactly how I always think (and explain) it.

Remember, a pressure washer can take the paint off your car.....:ROFLMAO:
 

MikeF

Member
First Name
Mike
Joined
Sep 18, 2021
Threads
0
Messages
5
Reaction score
7
Location
Denver, CO
Vehicles
GMC Denali
Occupation
Photographer
Country flag
I checked through the thread to see if this Webcast was already referenced, and it doesn't appear to be. It has a discussion from the Tesla Q1 Financial Results and Q&A Webcast, and includes Elon, during a discussion of 800V Architecture. Maybe since this was discussed during the Q1 Earnings Call, more study revealed that even more advantage could be gained from 900V Architecture. Like many CT related issues, they are still somewhat fluid.

 


SwampNut

Well-known member
First Name
Carlos
Joined
Jul 26, 2021
Threads
6
Messages
702
Reaction score
975
Location
Peoria, AZ
Vehicles
Tesla M3LR, Gladiator Rubicon
Occupation
Geek
Country flag
Eh... if sized and applied correctly transformers typically have an efficiency rate in the high 90's.
You seem to be suggesting that's trivial. I don't care if it's just 3% loss, that's a ton. Plus more heat, something battery systems already struggle to control.
 

Bill906

Well-known member
Joined
Mar 21, 2020
Threads
3
Messages
882
Reaction score
2,024
Location
Wisconsin
Vehicles
Jeep
Country flag
You seem to be suggesting that's trivial. I don't care if it's just 3% loss, that's a ton. Plus more heat, something battery systems already struggle to control.
You said there is a lot of heat and losses. "a lot" is subjective. I personally would not use "a lot" or "a ton" to describe the heat loss in a well applied transformer. Any voltage change is going to have some losses. If the correct method is applied and sized correctly, it would not, relatively speaking, be "a lot".
 

Crissa

Well-known member
First Name
Crissa
Joined
Jul 8, 2020
Threads
90
Messages
10,024
Reaction score
16,265
Location
Santa Cruz
Vehicles
2014 Zero S, 2013 Mazda 3
Country flag
AC/AC transformers are the most efficient electronic devices known to man.

But anyhow, if V3 Superchargers are internally CCS 2016 compliant, then there's no issue.

-Crissa
 

Jescocom

New member
First Name
Joe
Joined
Jul 2, 2022
Threads
0
Messages
1
Reaction score
0
Location
Memphis, TN
Vehicles
2017 Model X
Occupation
Retired
Can someone please explain what this means? Does it mean better charging times? More utility, better safety?
Power, i.e. Wttage, equals volts times amps. (P=E*I, ohms law). So, the more voltage you have ,the less amperage you need to produce the same amount of power. More Voltage with the same amount of amps would mean more power! I have no Idea if it would effect charging, but it would definitely effect torque!

 

 
CYBERBACKPACK
Top