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DC Charging for the Roadster

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Eberhard

#421 Model S #S32
Oct 17, 2010
1,149
11
Germany
I think we should apply with Tesla to open the DC Charging to the Tesla Roadster as an option. This would give Tesla immediately an existing user base for testing the new fast charging infrastructure for the Model S. No need for 3-ph charging the Roadster or Model S. Be able to use a small 50kg (30kW) external DC Charger at 3-ph 240-277V 40A when needed. The Tesla Roadster share the same cells with the 260km or 370km range version of Model S. Therefore the fast charging within 45min to 80% should work on the Roadster too.
 
I support the application to upgrade Roadsters to the new charging port architecture. The Roadster owners are the best possible user group to start with: addicted to their vehicles, can/will help with funding the upgrade, and can make good use of fast DC charging during road trips. An adapter for CHAdeMO would be nice, since charging the 53kWh pack with 50kW nearly triples the speed of the on board charger + HPC combination.
 
I think, that Tesla's DC Charging shares the same protocol and should be compatible. I was talking to JB Straubel regarding 3-ph because of his promise to support 3-ph charging with Model S. In my discussion with him and his colleges they lay out the future philosophy about charging.

First: home charging: 10kW for Model S even with 300miles is enough for overnight. Those how want speedier charging, a second onboard charge can be ordered (+15kg weight). Maybe this two can be employed on different phases.

Second: Fast charging. DC 90kW using 9x 10kW onboard charger in an external setting, powered by 277V/480V 3-ph 120A. Any other external charger whether 1-ph or 3-ph using Teslas DC interface can be used as well.
Tesla is going to setup their own charging network, because the most CHAdeMO do not support more then 50kW and have not the capability to charge the Model S within 45min to 80% SOC.


I want to charge with at least 22kW whether 3-ph or DC with my Roadster and/or Model S.
I want to take advantage on Tesla's new 90kW charging station.

Can be done with external DC Charger, but how to get access to the Roadster BMS. Access to ESS is be possible - physically spoken.

This is a total new approach to me but the result my be a charging time between 45-60min whether with CHAdeMO or any other external DC-Charger. I would like the 22kW Charger from BRUSA too.
 
First: home charging: 10kW for Model S even with 300miles is enough for overnight. Those how want speedier charging, a second onboard charge can be ordered (+15kg weight). Maybe this two can be employed on different phases.

A second charger does little to help when most people have no way of getting 32A from one phase, never mind the 43A required for 10kW. i'd wager that most households in Norway would have a problem using more than 20A from one phase over long periods of time. That is 4.6kW or a charge time of 22 hours from empty (with 85% charging efficiency). Many will be restricted to 16A, or 27 hours from 0-100%. Certainly on road trips, more than 16A is very rare to come by.

Funnily, this means that for a road trip, the 160 mile pack is enough as that is what you can recharge overnight. Day charging would have to be by CHAdeMO and they're being spaced close enough together over here for using less than half the 160 mile pack between chargers.

Maybe this is why they do not support CHAdeMO, to entice people to buy the large 300 mile pack ?

Tesla is going to setup their own charging network, because the most CHAdeMO do not support more then 50kW and have not the capability to charge the Model S within 45min to 80% SOC.

I'll believe this when I see the chargers pop up. I'm not optimistic though.
 
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90kW on the German 400V grid are more than 130 A ... beside the 135kg , it can't be mobile , cause the biggest Plug is rated only for 125 A ...
i was talking about a external setting means a stationary charging station, connected to the german grid with 240V/400V and 125A it will do at least 88kW in america its rated with 90kW at 277V/480V 120A.

my mobil version would be 3x10kW and 50kg weight. or the Brusa Charger NLG6 with 22kW with only 12kg
 
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I'll believe this when I see the chargers pop up. I'm not optimistic though.

Tom Barnard Communications Director of Nissan GB said today "We're having talks with Little Chef to explore feasability of installing a network of EV fast chargers at their restaurants"

If you take a look at the Little Chef map you'll see why Model S MUST support CHAdeMO...

http://www.teslamotorsclub.com/showthread.php/6462-Little-Chef-and-Chargemaster-installing-UK-national-charging-network?p=85928&viewfull=1#post85928
 
Tom Barnard Communications Director of Nissan GB said today "We're having talks with Little Chef to explore feasability of installing a network of EV fast chargers at their restaurants"

If you take a look at the Little Chef map you'll see why Model S MUST support CHAdeMO...

http://www.teslamotorsclub.com/showthread.php/6462-Little-Chef-and-Chargemaster-installing-UK-national-charging-network?p=85928&viewfull=1#post85928
I think he meant the Tesla DC 90kW chargers.

They might pop up in the US, but I'm not expecting them anywhere in Europe soon.
 
I wouldn't be opposed to it as you'd only need to have a battery hookup and a twisted pair to the ESS CAN bus to monitor voltage levels and charge rate. Maybe put a CHAdeMO in the trunk? Or Retrofit the roadster's now obsolete charge port to the new tesla design?

I was told by someone, whom I can't think of his name, that there is a strong possibility of a retrofit kit for the roadster.
 
The Tesla Roadster share the same cells with the 260km or 370km range version of Model S. Therefore the fast charging within 45min to 80% should work on the Roadster too.

I was told at the Tesla factory event that the no Model S model uses the same cells as the Roadster.

However if DC chargers become common, it would be very useful to be able to use them to charge the Roadster, even if it is limited to 20kW.
 
I was told at the Tesla factory event that the no Model S model uses the same cells as the Roadster...
I think they may have changed plans with regards to cells.
The original plan (I think) may have been to use Roadster type cells in the 160mi & 230mi packs until the next gen cells were ready for the 300.
But, apparently, the new cells are so good, that they are ready to use them first (in the 300 mile pack at launch) and may use lesser numbers of the same cells in the lower range packs.
(Basically with some empty space in the pack.)
I guess it is more cost effective to use less of the new cells than more of the old cells. Probably helps a lot with weight too.
 
So less cells means less weight = better performance? I specifically asked the battery guys in Fremont and they claimed packs would weigh the same but would not tell me how they would accomplish this. I asked if some lower power cells would be mixed with some higher power cells and was told too many problems with mixed cells. It will be interesting to see how they approach the problem.
 
I am not sure they will ever tell us exactly what they put inside. Trying to keep it somewhat of a mystery...

Random tidbit I did hear - apparently, long ago, they had selectively removed some cells from a pack that went into VP11, to see if people could tell, and if the logic to workaround bad cells was OK.
Apparently no one noticed or complained about it...

--

So less cells means less weight = better performance?...

So far they have only quoted one number for 0-60, not making it dependent on pack type.
(Well, there is the Sport option with even better performance.)
It will be interesting to see if 160 mile and 230 mile Model S variants offer the same performance as base 300 or not.
One would think that the packs would have different characteristics, from the aforementioned weight difference, to maximum power output (C rate).
At the end of the day, I think they program in the performance they want to the firmware, and then make sure the rest of the components are up to the task.
 
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So less cells means less weight = better performance? I specifically asked the battery guys in Fremont and they claimed packs would weigh the same but would not tell me how they would accomplish this. I asked if some lower power cells would be mixed with some higher power cells and was told too many problems with mixed cells. It will be interesting to see how they approach the problem.

I was told by a Tesla employee that all the packs would be the same weight and use the same number of cells, but with different chemistry/energy density. The original plan was to have more cells for the 300mi pack (in the rear of frunk).

The down side (for Tesla) of the new approach is that they will have to inventory 3 distinct battery packs instead of just adding or removing cells.
 
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