You reinforced the point I was making: CHAdeMO uses CAN over separate physical pins. Supercharging uses a PHY that's modulated on to the pilot signal. You have to build different transceivers for this. You need different inlets. Etc...
I think it is more nuanced than that. Tesla does the analog part of the handshake exactly like CCS. When it switches to digital communication, it uses a CAN bus, not PLC. I think they did that because it duplicates what the car does with the onboard chargers (using CAN to communicate) and the superchargers are basically the onboard chargers chained together for more power. I do however agree with your point that they two are not compatible and designing the Roadster for CHAdeMO would be a different ballgame than for superchargers.
Yeah that sounds familiar. I think it was nlc's thread that dissected the Supercharger operation... lots of good detail there.
Well, hopefully a moderator will break off the CHAdeMO portion of the thread, and start a new thread dedicated to that concept. Getting Supercharger access, again, isn't a technical problem. There's no money needed to study it... anybody with a Roadster would likely WANT the Supercharger access for their car. Any technical issues are ALL known by Tesla, so what you would be studying, I have no idea. Supercharger access is 100% owned and controlled by Tesla. No amount of study and money spent will change that dynamic. Perhaps it will make you feel like you did something positive after you spent a lot of money and Tesla simply said no to Supercharger access? If they said "yes", Tesla surely doesn't need your "study". Secondly, CHAdeMO will NEVER be at "Supercharger charging rates", since it's limited currently to 125 amps, and the design spec is 200 amps max. Supercharger is already at 370 amps. So, with the above said, you'd rather have public 30 amp public J1772 (with adapter) or RV park charging when traveling? If any car were going to get either a Model S inlet, or Supercharger access, I would assume the Roadster would be that car. Why Tesla has not offered that, even with a current technology 70kWh battery, is more than a bit odd to me. Maybe that should be the focus of your efforts? To get a concrete answer from Tesla as to why there is no Supercharger access available for the Roadster, at any price?
It didn't take much digging to find the stated reasons for no Supercharger: [FONT=HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif]"... at the announcement, and it was stated that due to [/FONT]pack cooling[FONT=HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif] and [/FONT]power electronics reasons[FONT=HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif], Supercharging cannot be done on a Roadster."[/FONT] [FONT=HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif]So, while CHAdeMO at 125 amps / 400 VDC may or may not have issues, 370 amps / 400 VDC certainly will.[/FONT] [FONT=HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif]Now you know where to spend research dollars. It's not on relays and Supercharger connectors (which Tesla has plenty of). It's the cooling system (somewhat easy) and power electronics (good luck!!!). [/FONT]
That makes complete sense. If I listen to my Model S when supercharging at high current, the cooling system is going very full on. Ivan the power transfer that's not surprising. furthermore, when charging it's often only 2/3 of the power from a charger which is going to the battery if I monitor the detail. That tells me that the earlier Roadster would need material mechanical changes to cope with any higher charge than the 70A.
Should see my post earlier in this thread. I did a test trial with ESS at HPWC and I electronically disable the active ESS cooling, and monitored the sheet/bricks/cell temperatures charging at 70amps, and battery temps were still in nominal ranges adding 55% to my SOC. ESS rate of temperature rise at ~16kW gave me how much heat was being generated. After I was done charging, I enabled the ESS cool down, and it brought the temperature down pretty fast, I think it's more than good enough for 60kW or higher charging. The PEM would be bypassed with supercharing with an Supercharging box, so no issues there. No luck needed here...
I agree based on my observations when charging at 16kW. The cooling system is adequate for supercharging. If you're in an extreme environment or plug in with a hot pack then supercharging might have to be throttled a little to let the HVAC cooling catch up. Obviously power electronics are not an issue because the PEM is bypassed. You would need a comm board that connects to the CAN bus but that's not power electronics.
Yes, it does seem odd that the power electronics were even mentioned. Of course that is not used with DC charging (Supercharger or CHAdeMO). Again, why not make concrete efforts to get the "holy grail"? That is permission from Tesla, not technical solutions. Lobbying !!! Secondly, I'm a bit stymied by anybody who would not want faster charging only because it doesn't have a Tesla brand on it (or that it's not the fastest). Currently, the AC onboard charger puts 37 to 50 amps max DC into the battery. Over 100 amps is a big improvement over status quo.
I'd be very happy just to get access to the Supercharging network, even at 50A. Or, CHAdeMO, for that matter. Just that many more options to charge, raising the chance to actually be able to do so when on the road. And, a lot faster than the under 30A (net) we get, if you're lucky, from the L2 J1772 outlets found at the malls.
I'd love my Roadster to be able to use the superchargers; isn't the big issue for Tesla that these are optimised to fill a Model S at max speed while protecting the battery? They have relatively few stalls and want Model S owners to avoid queueing. Put a Roadster there which is drawing just 70A and may tie the slot up for 2 hours and that's a problem at popular locations. at max charge rate (and note the Model S does not allow the owner to vary the rate of charge at a supercharger) the supply is 400V and about 380A. What's the absolute limit a Roadster could absorb without battery damage?
What makes you feel that the supercharger scare your property to use? Do you have tesla permission? Without that are you going to be responsible for any damage to the supercharger? Of course we know you will be responsible to damage to your car. Will you pay for the use of the supercharger like the S60 owners do?
I don't see where wk057 has stated any such thing. Notice the terms he is using: In essence he is describing the relatively little cosy for a large Public Relations return if TESLA were to do this...
A third-party JdeMo adapter for the Roadster is in the works, and for a planned price of $3K. If it really is feasible and will not cause problems for the battery system, that calls into question the assertions that engineering a Supercharger conversion is impractical. I can understand that Tesla may have insufficient motivation to do it, and it may not be possible for a third party to do it, but it could be done.
This has been hashed over repeatedly... without Tesla participating, there is no Supercharger access for ANYBODY. Period. So, how exactly do you expect to steal Tesla's Supercharger service?
Take a chill pill... He didn't say it should be done behind Tesla's back, he said that if a third party can do CHAdeMO for 3 grand then it's feasible for Tesla to do supercharging for 3 grand. Which it is.
Depends on what you count as supercharging. Even at the start at the thread it was speculated that ~30kW "supercharging" can be done for cheap using a similar piggy back system that reused as much existing parts as possible. What was disputed was whether Tesla wanted to allow such low power supercharging. Installing a 90kW+ system that is integrated into the car (where the port actually switches between AC and DC and the firmware is fully aware of it) is a different matter. Even doing the same JdeMO method, Tesla will have start from scratch, while Tony already has the RAV4 EV version developed.
I wonder if distracting Tesla from Model 3 is really the best thing for this... I'm happy if Tesla doesn't get in the way of JdeMO and gets 3 as a platform for the next Roadster... I'd like a less squeaky roof and the ability to just take the top off with the push of a button than have to screw and unscrew the hardtop (and the eventual squeaky noises that follows).