Supercharger - Fremont, CA - 47400 Kato Rd (not completed, V3 test site Mar 2019)

AMPd · Nov 5, 2015

WOW! PG&E already installing the transformer, largest hurdle... hurdled!

Tyl · Nov 6, 2015

The green box PG&E was working on yesterday was a connection box and NOT a transformer. Here are a few photos from today. A transformer or two near the building. I'm not sure if these are related to the superchargers or not?!?! These two transformers were on site in post 30...so they may be for the building and not the superchargers. I'm kinda thinking the transformer we need will be placed much closer to the Distribution cabinets, superchargers; and central to the supercharger pedestals. I don't readily see a pad for it near the conduit area. In post 44 (the plans) we see these two transformers in the drawings so they are probably for the building:wink:

BobbyKings · Nov 9, 2015

I would favor Dual P(ort) charging if availability of stalls would allow for this. Right side port may be locked for now but must or may be pre-wired to cater for the RHD market (Japan, Australia, UK).
That way we could achieve > 600 mph charge speed and overtake the Porsche MissionE also on charging speed even before it hits the market. If ever.
I think I like the Dual P option...:smile:

bxr140 · Nov 9, 2015

BobbyKings said:
I would favor Dual P(ort) charging if availability of stalls would allow for this. Right side port may be locked for now but must or may be pre-wired to cater for the RHD market (Japan, Australia, UK).
That way we could achieve > 600 mph charge speed and overtake the Porsche MissionE also on charging speed even before it hits the market. If ever.
I think I like the Dual P option...:smile:

Charging speed is essentially a function of the battery and not the charging system, so charging speeds would not increase.

BobbyKings · Nov 9, 2015

I would not be too sure about having maxed out yet. And I'm sure Tesla won't let get Porsche ahead by any means or measure. And this may be one of ways to achieve this objective. Considering the location - Fremont- they may be preparing for more than just more of the same. It's tesla, you know :biggrin:

wk057 · Nov 9, 2015

bxr140 said:
Charging speed is essentially a function of the battery and not the charging system, so charging speeds would not increase.

Yep. Batteries would explode.

apacheguy · Nov 9, 2015

wk057 said:
Yep. Batteries would explode.

There is evidence that they can support up to 150 kW, no?

wk057 · Nov 9, 2015

apacheguy said:
There is evidence that they can support up to 150 kW, no?

Depends. I've been able to get the cells to handle nearly 300kW charging (equivalent extrapolated out) but only for super short periods at specific SoC before they.... well, overheat and explode. Unfortunately Tesla's thermal management is probably already at its maximum possible potential for faster charging, along with the in-car cabling.

I could see 150kW for very short periods at some SoCs at the beginning of a cycle if it were started at the right point with a cold pack, but based on my data it's unlikely Tesla would push the cells this hard or harder given the immediate degradation it seems to cause.

apacheguy · Nov 10, 2015

60 kWh Model S are known to charge up to 112 kW. So from a degradation standpoint, Tesla must feel comfortable pushing the cells to ~1.9 C charging. I guess the issue is that less heat is generated in the 60 so that's how they get away with it not causing immediate degradation?

bxr140 · Nov 10, 2015

apacheguy said:
60 kWh Model S are known to charge up to 112 kW.

Only at deep DOD, and only for a few seconds at most. IMHO, the initial charging rate spike is really just the marginally controlled momentum of the current ramp-up. From a sustained charging perspective, A 60kwh barely stays in the 80's for more than a minute or two.

I for one would love to see more area under the taper curve, but I don't think the chemistry has much more in it. Perhaps a few percent at best.

The whole dual plug thing is silly. Tesla isn't stupid. The charging system isn't the limiting factor. When chemistry allows for more power, all tesla needs to do is swap out the charger stacks (or even just some of the chargers) in the supercharger cabinets.

AMPd · Nov 10, 2015

I must be the only one who feels like the current charge rate is perfect! I've done a few road trips and the time to charge was exactly what I needed to stretch and load up on calories.
The problem at most of the places I stopped to charge was not enough stalls.
Which tesla has solved with this location.

P.S. Porsche hasn't done anything other than talk, I'll believe their claims when they actually release a car that does what they claim.

apacheguy · Nov 10, 2015

bxr140 said:
Only at deep DOD, and only for a few seconds at most. IMHO, the initial charging rate spike is really just the marginally controlled momentum of the current ramp-up. From a sustained charging perspective, A 60kwh barely stays in the 80's for more than a minute or two.

This is incorrect. The 60 kWh sustains, for several minutes, charge rates in excess of 100 kW (1.8-1.9 C rate).

See islandbayys video for a refresher:

Video: Tesla Model S 60 kWh Now Supercharges at Over 100 kW Thanks to Firmware Update | Inside EVs

Additionally, there is evidence that a 60 kWh B pack will charge slightly faster than a 60 kWh A pack (which is shown in above video).

wk057 · Nov 10, 2015

apacheguy said:
This is incorrect. The 60 kWh sustains, for several minutes, charge rates in excess of 100 kW (1.8-1.9 C rate).

See islandbayys video for a refresher:

Video: Tesla Model S 60 kWh Now Supercharges at Over 100 kW Thanks to Firmware Update | Inside EVs

Additionally, there is evidence that a 60 kWh B pack will charge slightly faster than a 60 kWh A pack (which is shown in above video).

Keep in mind that the evidence suggests that the 60 packs are slightly under rated and the 85 packs are slightly over rated.

The 85 packs are 16 modules of 6s74p for 7104 cells. The 60 packs appear to be 14 modules of 6s64p for 5376 cells. 85/7104 = 11.97 Wh/cell. 60/5376 = 11.16 Wh/cell. We know they're the same cells, so both can't be right. Since I know the 85 pack is pretty close to it's rating (based on my testing I believe it's closer to about 81-82 kWh max), applying that to the 60 pack gives it ~64kWh. So 100 kW would be ~1.56C. Even at 60 kWh, 100 kW is 1.67C. For comparison, 150 kW on an 85 pack would be more like 1.83C. 120 kW on an 85 pack is about 1.46C.

The under-rating on the 60 packs would partly explain how 60 owners can appear to use more of their pack capacity on their trip meters vs 85 owners.

Some of my testing suggests that the supercharger taper curve is a thermal based worst case scenario that is just mapped based on pack voltage. When I attempt to fast charge individual cells from ~10% SoC while maintaining a set maximum exterior case temperature (based on internal heating only) with the cell at room temperature I get a curve very similar to the supercharge taper curve at rates > 1C. The cell will accept higher power, but will heat up... and explode.

I think my Tesla cell testing death-by-explosion toll is easily over 50 by now. lol.

bxr140 · Nov 10, 2015

apacheguy said:
This is incorrect. The 60 kWh sustains, for several minutes, charge rates in excess of 100 kW

I have a b-pack 60 and for the ~50 supercharging events it's been through--many starting with under 10% remaining capacity--it won't do anything close to the video you posted.

That video is very unrepresentative of reality with a 60.

kwoo4424 · Nov 25, 2015

...anyone seen updated SC progress here ...

Tyl · Nov 25, 2015

I stopped by today 1:30PST. No changes whatsoever. I think the inside of the building is taking priority. This site will not build up until they are ready to open the building next year. We may not see any action at this site until then. Think February March next year before its open.