Typical Supercharging rate?

[Lloyd]

From my experience this weekend it doesn't appear to work that way. It looks like the first car to plug in continues to get whatever it needs to complete its charge, and the second car gets whatever is left over, regardless of its SOC.

This is correct, but the 2nd to plug in still has the limitations of their SOC. The car will not accept a rate that is more than what is safe for the battery. Tesla has designated the cars as Primary and Secondary. Unless the secondary plugs in shortly after the primary there is usually very little if any limitation for the secondary.

 

[DavidM]

Ron,

Exactly!

Although I believe the Superchargers continue to charge at a HPWC rate even at relatively high SoCs, I wouldn't mind seeing them tapper off more if that helped regulate the use of the Superchargers. When something is free people frequently exhibit very stupid behavior.

Larry

Like the buffet line on the first day of a cruise!!
It'll still be there tomorrow . . :smile:

 

[Yggdrasill]

Your numbers are way too optimistic. I just completed a 800 mile 2-day trip from Silicon Valley to LA with 6 supercharger stops. At freeway speeds of 70-75 mph, some elevation change and temperatures mostly in the 40's (F), I was using 400 wh/mi. So my 265 mile "rated" battery is in fact a 210 mile "real" battery. With superchargers 115 miles apart on I5, you can't skip one. And it takes 45 minutes to add the 160 rated miles needed to cover 115 actual miles. The only time I did better than that was adding 180 miles in 45 minutes with the battery was at 1 mile of range left!

Of course, superchargers should be placed even closer along routes with higher speed limits. (Here in Norway I think the longest stretch of road with 65 mph speed limits is around 50 miles. Almost all long distance trips are usually spent on a 55 mph road.) But even with your figures, 400 Wh/mile, chargers 100 miles apart would be fairly good. It would be something like this:

1. Arrive at 1st SC with 65% SOC. You don't stop, just keep going.
2. Arrive at 2nd SC with 18% SOC. Charge to 50+% SOC in 18+ minutes. Leave.
3. Arrive at 3rd SC with 3% SOC. Charge to 50+% SOC in 27+ minutes. Leave.
4. Continue like above.

(5 minutes extra at each charger for extra margin might be a good idea.)

 

[dennis]

But even with your figures, 400 Wh/mile, chargers 100 miles apart would be fairly good. It would be something like this:

1. Arrive at 1st SC with 65% SOC. You don't stop, just keep going.
2. Arrive at 2nd SC with 18% SOC. Charge to 50+% SOC in 18+ minutes. Leave.
3. Arrive at 3rd SC with 3% SOC. Charge to 50+% SOC in 27+ minutes. Leave.
4. Continue like above.

(5 minutes extra at each charger for extra margin might be a good idea.)

I'm having trouble following your math, so maybe I am missing something. Here are my assumptions:

1) 85 kwh battery has 81.6 kwh usable (.308 kwh/mi*265 miles=81.6 kw)
2) At 400 wh/mi driving 100 miles consumes 40 kw.

That would mean you arrive at the first supercharger having consumed 49% of the battery capacity. I doubt if many people will take the chance on bypassing it.

I'm also skeptical of charging from 3% to 50% in 27 minutes. My 2 real world data points are 7%->23% in 15 minutes and 1%->68% in 45 minutes.

 

[dennis]

Impact of 60kwh batteries on the Supercharger network

My experience with using the Supercharger network the past weekend got me thinking about what will happen when owners of 60kwh batteries start using the I5 corrider between Silicon Valley and LA. Assumptions:

1) The 230 mile ideal range battery will be around 203 miles of rated range (same ratio as for 85kwh battery)
2) Travelling at 75mph on I5 uses about 400wh/mile.
3) Covering the 115 miles between superchargers at this speed requires 142 (downhill) to 172 (uphill) rated miles of range. The median was 160.
4) Everyone will want some buffer miles to account for cold/hills/wind/etc. Lets say 20 miles of rated range.
5) The 203 mile rated range battery with need to be charged to 180 miles at every supercharger along the route. This is an 89% SOC on the 60kwh battery, or a complete standard mode charge.

For me to go from 20 miles rated range to 180 miles rated range in the 85kwh battery took 45 minutes if I was the only one charging. I believe it will take longer to do this on the 60kwh battery since it will be reaching a higher SOC. Does anyone have a way of guesstimating how much longer?

 

[aviators99]

My experience with using the Supercharger network the past weekend got me thinking about what will happen when owners of 60kwh batteries start using the I5 corrider between Silicon Valley and LA. Assumptions:

1) The 230 mile ideal range battery will be around 203 miles of rated range (same ratio as for 85kwh battery)
2) Travelling at 75mph on I5 uses about 400wh/mile.
3) Covering the 115 miles between superchargers at this speed requires 142 (downhill) to 172 (uphill) rated miles of range. The median was 160.
4) Everyone will want some buffer miles to account for cold/hills/wind/etc. Lets say 20 miles of rated range.
5) The 203 mile rated range battery with need to be charged to 180 miles at every supercharger along the route. This is an 89% SOC on the 60kwh battery, or a complete standard mode charge.

For me to go from 20 miles rated range to 180 miles rated range in the 85kwh battery took 45 minutes if I was the only one charging. I believe it will take longer to do this on the 60kwh battery since it will be reaching a higher SOC. Does anyone have a way of guesstimating how much longer?

1) The 60kWh battery has 208 miles of rated range (different ratio as for 86kWh battery)
2) This is the number for the 85kWh battery. The 60kWh battery is more efficient.
.
.


I agree with the issue, though.

 

[VolkerP]

As a rule of thumb, where 85kWh Model S is capable of doing road trips with 30+min supercharging stops, my expectation with the 60kWh Model S is to plan for 60 minute stops. Initial charge rate for the 60kWh will be around 60kW and will start to taper off well before approaching 50% SOC = 104 miles, as observed with the 85kWh Model S. You have to charge longer to make sure the next SC station is in reach with planned highway speeds, some degradation in the battery pack, and some buffer.

 

[dennis]

As a rule of thumb, where 85kWh Model S is capable of doing road trips with 30+min supercharging stops, my expectation with the 60kWh Model S is to plan for 60 minute stops.

My experience with the 85kWh battery is that it takes 45 minutes of charging to add the necessary range (160 rated miles) to reach the next supercharger station 115 miles away.

 

[adurstewitz]

After reading through this thread it occurred to me that the solution could be simple... only allow a single car to charge for a max of one hour.

Now I realize there are ways to tune this to be more exact. But everyone, even selfish people, can set their watch to one hour.

 

[dsm363]

After reading through this thread it occurred to me that the solution could be simple... only allow a single car to charge for a max of one hour.

Now I realize there are ways to tune this to be more exact. But everyone, even selfish people, can set their watch to one hour.

I like this solution. The need to have 80A HPWCs off to the side as well for the 40 kWh versions or for people who have longer at the location or to top off after a Supercharge.

 

[andrewket]

I like this solution. The need to have 80A HPWCs off to the side as well for the 40 kWh versions or for people who have longer at the location or to top off after a Supercharge.

I don't think you want to try to accommodate 40kWh vehicles at these locations. 40kWh are good for short commuter trips, not road trips.

 

[Kipernicus]

As a rule of thumb, where 85kWh Model S is capable of doing road trips with 30+min supercharging stops, my expectation with the 60kWh Model S is to plan for 60 minute stops. Initial charge rate for the 60kWh will be around 60kW and will start to taper off well before approaching 50% SOC = 104 miles, as observed with the 85kWh Model S. You have to charge longer to make sure the next SC station is in reach with planned highway speeds, some degradation in the battery pack, and some buffer.

In another thread,

I figured we had plenty of range to make it back to San Jose the same way we came, but instead decided to check out the Gilroy SC on the way back and see what type of charge rate I could get. And its free, so I couldn't pass that up! Got there with 67 rated/ 65 projected miles left (132 miles traveled). I averaged 306 wh/mi.
When I first started charging the display read 72mi/hr, 75amps, 309V. At the end it was reading 102mi/hr, 120amps, 341V. After 1 hour I left with 175 miles on a standard charge.

Confirms what many of us suspected, that with a 60 the supercharger dials down the charge rate and a 60kWh car needs to take more time at the SC. It takes an hour what an 85 can gain in half an hour, or something like that. I hate to admit it, but soon the 85's will be complaining about superchargers being 60'd for an hour or more. Having HPWC to supplement the SC is a very good idea. And sometimes you want to park (and charge) for longer than an hour.

 

[cinergi]

I'm at the SC in Milford, CT getting ready to film a SC session ... stay tuned for an update :smile:

 

[cinergi]

Rather than post a boring > 1 hour video, I plotted a graph for ya ...

Edit: This was done in ~20F weather so there weren't any effects of tapering the charge to keep the battery temps down.

 

[dennis]

Rather than post a boring > 1 hour video, I plotted a graph for ya ...

View attachment 15266

Edit: This was done in ~20F weather so there weren't any effects of tapering the charge to keep the battery temps down.

This jibes with my experience of ~45 minutes required to add 160 miles of rated range, which is what I needed to travel 115 miles @75 mph to the next supercharger location.

Thanks for posting this detailed graph, it illustrates the futility (selfishness?) of attempting a range charge at a supercharger station.

 

[apacheguy]

That data is very interesting. It makes me wonder about the trip I took stopping at 3 different superchargers in California. Here are a few things I noticed:

1. The supercharger never showed above 370 volts. I'd say the average was more like 350. But towards the end of your charge you were picking up 400. Better quality electricity from the grid in Connecticut?
2. It also seems that towards the beginning of your charge your MS was drawing almost 250 amps. Mine was physically limited to 225 amps, so I'm not sure how you were able to draw that much.
3. As a result of 1 and 2, my car never drew 90 kw even when far below 50% SOC

 

[arg]

That data is very interesting. It makes me wonder about the trip I took stopping at 3 different superchargers in California. Here are a few things I noticed:

1. The supercharger never showed above 370 volts. I'd say the average was more like 350. But towards the end of your charge you were picking up 400. Better quality electricity from the grid in Connecticut?

The voltage shown while supercharging is the output of the charger (unlike the AC charging case where the display shows the input to the charger). So it depends on the state of charge of the battery (offset by how much charge current you are putting into it), and should be unaffected by grid voltage.

2. It also seems that towards the beginning of your charge your MS was drawing almost 250 amps. Mine was physically limited to 225 amps, so I'm not sure how you were able to draw that much.

Which supercharger were you using, and who else was there? One of the 9-module chargers will be more limited than the 12-module chargers that are shared between two bays. On the other hand, if you are sharing the charger and someone is in the other slot, your current will be limited. I don't think anyone has compiled a full list of which models of charger are where (best would be to photo the rating plate, as the example for Harris Ranch here which suggests that one is a 9-module serving the single bay there).

3. As a result of 1 and 2, my car never drew 90 kw even when far below 50% SOC

The graph suggests you only get full power up to something like 30% SOC. Not clear if the first bit is less because there is also a reduction below ~15% SOC, or if that was just a startup effect.

 

[FredTMC]

I like this solution. The need to have 80A HPWCs off to the side as well for the 40 kWh versions or for people who have longer at the location or to top off after a Supercharge.

I agree. It would be simple to code the SCs to limit users to 45min of use when all stations are full &/or others are waiting. Then people who want a "Top off" can use an HPWC (if TM adds them).

Otherwise, human nature is that people tend to be rude. In general, TM needs to grow the #stations to stay ahead of demand. If it becomes a common occurrence to wait for charging, everyone's going to be irritated. Nothing worse than unexpected delays on long road trips.

.

- - - Updated - - -

In another thread,


Confirms what many of us suspected, that with a 60 the supercharger dials down the charge rate and a 60kWh car needs to take more time at the SC. It takes an hour what an 85 can gain in half an hour, or something like that. I hate to admit it, but soon the 85's will be complaining about superchargers being 60'd for an hour or more. Having HPWC to supplement the SC is a very good idea. And sometimes you want to park (and charge) for longer than an hour.

Hmmm... TMs "road trip" configurator webpage clearly shows it takes 41min to charge from 10%-80% SOC for the 60khw battery. I expected real world to be "a little" worse than 41min. Giants2001 charge didn't start from 10% SOC. He started with about 30% charge (65mi rated)

 

[cinergi]

That data is very interesting. It makes me wonder about the trip I took stopping at 3 different superchargers in California. Here are a few things I noticed:

1. The supercharger never showed above 370 volts. I'd say the average was more like 350. But towards the end of your charge you were picking up 400. Better quality electricity from the grid in Connecticut?
2. It also seems that towards the beginning of your charge your MS was drawing almost 250 amps. Mine was physically limited to 225 amps, so I'm not sure how you were able to draw that much.
3. As a result of 1 and 2, my car never drew 90 kw even when far below 50% SOC

My session showed a max of 255 amps (I drew a max of 243). I'm wondering if the one you were at negotiated a lower rate.
I was at 88-90 kW from SOC = 54 to 82 -- 6 minutes. It tapered before and after those points. Not much time at 90 :-(

The HPC is capable of the same power if your rated range is 250+ ... basically if you're doing a range mode charge, use an HPC not an SC.

 

[FredTMC]

Cinergi. Nice graph!