Supercharging not so super

[SigNC]

From what I can tell the 3 only makes an attempt to warm the pack to get to a point there is a little bit of regen. After that it doesn't seem to do anything to actively warm the pack. Just from what I've noticed from interaction. Also, I think supercharging S/X batteries seems in general to create much more heat than supercharging 3 batteries. You an hear an S or X fans wailing during supercharger sessions even when it's not hot outside. Conversely, it needs to be very hot outside before you hear a 3s fans kick on during supercharing to any real extent.

All that to say, I think with the fact more heat is generated supercharging S and X the batteries tend to warm up more while charging. Maybe the dedicated heater on it keeps going to higher temps where as on the 3 it does not. It would seem tesla could make a software change to where you could actively heat the pack while charging BUT I also remember reading somewhere that the charging profile is picked at the start of the supercharging session so maybe that would need to be changed too.

TL;DR drive your car further before you stop for a supercharging session or leave from a warmer garage.

 

[mswlogo]

I know people have tried to explain it before with stall choices, state of charge when one arrives etc. I cannot seem to get what I’d consider a supercharge. I plugged in with about 48% SOC. It said it would take an hour till full. 30 mins later it still says 50 minutes and I’m at 28kw for a charge of just over double my home charging speed. I don’t like that I’m being charged the same price per minute while they provide half the power that fee is supposed to get me. Of course at the top end of the battery I expect it to be reduced but not the majority of the charge. I’ve supercharged maybe 10 times and I never ever get close to what I’m supposed to for the price paid. 30 or 70kw. I follow the tips and it never changes my experience.

You answered your own question

The charger will also set up a "plan" or allocate "banks" up front and not deviate much from that plan (other than remove banks as it goes). So if you start with a lower SOC (e.g. 25%), by the time you do reach 50% it will often be at higher charge rate than if you started at 50%.

Also anything over 80% is often way off on how long it estimates it will take. Anything with a target of 80% it's a fairly good estimate.

Tesla wants you to start with low SOC (try their route planner) and generally discourages going above 80%, because you are wasting SC time.

Think 20-30% to 70-80% for fast SC. Not 40-50% to 90%

Since you are paying by the minute you should look at the charts for the best range to charge over for your needs.

State of NH (USA) also charges by the minute.

 

[EVDRVN]

From what I can tell the 3 only makes an attempt to warm the pack to get to a point there is a little bit of regen. After that it doesn't seem to do anything to actively warm the pack. Just from what I've noticed from interaction. Also, I think supercharging S/X batteries seems in general to create much more heat than supercharging 3 batteries. You an hear an S or X fans wailing during supercharger sessions even when it's not hot outside. Conversely, it needs to be very hot outside before you hear a 3s fans kick on during supercharing to any real extent.

All that to say, I think with the fact more heat is generated supercharging S and X the batteries tend to warm up more while charging. Maybe the dedicated heater on it keeps going to higher temps where as on the 3 it does not. It would seem tesla could make a software change to where you could actively heat the pack while charging BUT I also remember reading somewhere that the charging profile is picked at the start of the supercharging session so maybe that would need to be changed too.

TL;DR drive your car further before you stop for a supercharging session or leave from a warmer garage.

It should allow the charging to warm the pack if the pack is very cold which is when it would need that. Some of the charge speeds are extremely slow.

 

[SigNC]

It should allow the charging to warm the pack if the pack is very cold which is when it would need that. Some of the charge speeds are extremely slow.

Not disagreeing with this but I don't think the 3 batteries generate much heat charging, especially at lower rates, and from what I can tell the pack isn't actively heated (via the motors) but up to about 40f or so. It certainly would be nice to toggle to heat the pack more aggressively.

 

[Glamisduner]

A pack at 50 should not be significantly restricted from charging particularly at a low SOC. My 3 is constantly restricted even after an hour of driving. I 'm starting to think the 3 pack is much more restricted than others. MY 85D can charge faster at 40 than my 3 at 50 and even with my S at a much higher SOC. Even if it is 30 my so may be slow for a bit and then ramp up to a much faster speed where the 3 will charge much slower at 50-60 and never ramp and often slow over time to speeds lower than it would at that same SOC with a very warm pack. I can get speeds of 120kW when it is 70 plus out and the car has been driven. I think the 3 pack must be at about 80 to get the full SC speeds at any given SOC.

It could be part of the chemistry since the compounds in the new cells have to deal with expansion issues.

 

[EVDRVN]

It could be part of the chemistry since the compounds in the new cells have to deal with expansion issues.

Perhaps but that sure is a disadvantage, significant restriction even at 50 or 60 degrees. I hope that is not the case.

 

[brkaus]

Is this an urban supercharger or regular one?

 

[mswlogo]

A pack at 50 should not be significantly restricted from charging particularly at a low SOC. My 3 is constantly restricted even after an hour of driving. I 'm starting to think the 3 pack is much more restricted than others. MY 85D can charge faster at 40 than my 3 at 50 and even with my S at a much higher SOC. Even if it is 30 my so may be slow for a bit and then ramp up to a much faster speed where the 3 will charge much slower at 50-60 and never ramp and often slow over time to speeds lower than it would at that same SOC with a very warm pack. I can get speeds of 120kW when it is 70 plus out and the car has been driven. I think the 3 pack must be at about 80 to get the full SC speeds at any given SOC.

That's what I find too. If it starts "below" normal, for any reason, it stays on a slow track.
Of course it will speed up once the pack warms up. But even if it warmed up, by say 40% you'll be lucky if you ever see above 60 Kw for the rest of the charge.

It's like it allocates it's (Banks or Slots, whatever they are called) up front. It sees a cold pack and only allocates 1 or 2 slots (since that's the most it can take at initial plug in). Once it warms up it does not go back and add more slots (needed for really high speed charging). Even though nobody is in the next stall and they are available and could be used to charge faster. It doesn't do it.

I read it here that there are like 4 slots per pair of charging stalls and it allocates them between the pair. I forget the exact details on what they are called and how many there are. But that feels like what's going on.

I think this is why occasionally if you unplug at the right time (pack warmed up and still low enough SOC) and plug back in, it might allocate more slots, because the conditions are now correct to start off with more slots.

If you are using 4 slots and someone pulls into the next stall, it will take slots away. But it won't add them when it can.

I have got above 100 Kw when it was 30F out and the battery was good and low SOC (e.g. 20%) and just cleared for full regen by driving (meaning battery wasn't all that warm). Who knows what the pack temperature was at that point though. My guess is, a lot less than 80F.

This is all just a hunch of how it works.

 

[EVDRVN]

That's what I find too. If it starts "below" normal, for any reason, it stays on a slow track.
Of course it will speed up once the pack warms up. But even if it warmed up, by say 40% you'll be lucky if you ever see above 60 Kw for the rest of the charge.

It's like it allocates it's (Banks or Slots, whatever they are called) up front. It sees a cold pack and only allocates 1 or 2 slots (since that's the most it can take at initial plug in). Once it warms up it does not go back and add more slots (needed for really high speed charging). Even though nobody is in the next stall and they are available and could be used to charge faster. It doesn't do it.

I read it here that there are like 4 slots per pair of charging stalls and it allocates them between the pair. I forget the exact details on what they are called and how many there are. But that feels like what's going on.

I think this is why occasionally if you unplug at the right time (pack warmed up and still low enough SOC) and plug back in, it might allocate more slots, because the conditions are now correct to start off with more slots.

If you are using 4 slots and someone pulls into the next stall, it will take slots away. But it won't add them when it can.

I have got above 100 Kw when it was 30F out and the battery was good and low SOC (e.g. 20%) and just cleared for full regen by driving (meaning battery wasn't all that warm). Who knows what the pack temperature was at that point though. My guess is, a lot less than 80F.

This is all just a hunch of how it works.

The charger in your car is what is in the SC closet, they are stacked together VS the one in your car. These modules combined charge your car as you described. I don't see this behavior on an S.

 

[Glamisduner]

Perhaps but that sure is a disadvantage, significant restriction even at 50 or 60 degrees. I hope that is not the case.

this video explains the battery chem at about 2:15 seconds in.

Silicon oxide used in the 2170's has greater expansion than previous generations of batteries. This could be why tesla is more restrictive on charging but this is just speculation. They only use a little in place of graphite, but the expansion rate is 300-400% instead of only 3-7%. Tesla needs to account for this expansion when accounting for long term battery life. I can't help but to think this may result in stricter charging specification.

 

[Darthbenji]

Ok so it’s:

‘supercharger*’

*supercharging restricted to SOCs around 20%. All others just get ‘charging’.

What if youre on a road trip, know you need a charge and the charger that fits your trip comes along at 40%? It shouldn’t take longer or cost more to go from 40-80% than it does 20-80%.

Above 80% I totally get it. Actually I get the rest too. I think it’s a bs way to advertise and sell a product. In my experience, superchargers are way more expensive than gasoline. 200km for $20 is the most expensive fuel I’ve purchased. When I factor in the 200kms is really 120-140 with the cold range factor, it’s an absolutely ridiculous cost vs gasoline. They might want to let people know to bend over and grab their ankles showing up at a SC around 40%.

 

[Glamisduner]

Ok so it’s:

‘supercharger*’

*supercharging restricted to SOCs around 20%. All others just get ‘charging’.

What if youre on a road trip, know you need a charge and the charger that fits your trip comes along at 40%? It shouldn’t take longer or cost more to go from 40-80% than it does 20-80%.

Above 80% I totally get it. Actually I get the rest too. I think it’s a bs way to advertise and sell a product. In my experience, superchargers are way more expensive than gasoline. 200km for $20 is the most expensive fuel I’ve purchased. When I factor in the 200kms is really 120-140 with the cold range factor, it’s an absolutely ridiculous cost vs gasoline. They might want to let people know to bend over and grab their ankles showing up at a SC around 40%.

Your getting charged by time and not by total power delivery?

 

[Darthbenji]

Your getting charged by time and not by total power delivery?

Yes. Apparently they have to charge by the minute in Ontario which makes all this secret decoder ring stuff on how to charge even more valuable since they don’t do anything to mitigate, including explaining it.

 

[Evoforce]

I need to contact my state legislator to ask them to change the laws in Kansas. State laws are what prohibit Tesla (a non-utility company) from charging consumers by the kWh. These laws are why we pay the odd per minute rates. As public charging for EVs becomes more prevalent, this will impact more and more people.

Same in Arizona.

 

[animorph]

What if youre on a road trip, know you need a charge and the charger that fits your trip comes along at 40%? It shouldn’t take longer or cost more to go from 40-80% than it does 20-80%.

On a road trip we'll have charged just enough at the previous Supercharger to get to the next one at 10% to 20% SoC. Very seldom would we arrive with 40%, only at the start of a trip when we've charged to 100% (at home) to start. It's not like we arrive at a Supercharger by surprise at 40% SoC and decide to charge to 80% or 90%. Which still sounds like what you are describing.

Our average Supercharger stop is 31 minutes when traveling cross-country. However we had one stop where we had to charge from 69% to 99% when the Supercharger we were planning to stop at unexpectedly showed as closed on the nav. That took 54 long minutes. We reached the next open Supercharger at 6% SoC and had to drive a little slower to do that. So we have come close to your scenario. But that's very rare.

If your car never comes close to matching the kW vs SoC curves on TMC then talk to a Service Center. Otherwise, battery health determines the Supercharging taper and you just have to learn to optimize how you charge. I agree the current Supercharger costs are high, probably intended to support building more of them as opposed to just covering the electricity. And it sucks to have to pay by the minute, especially when your charge rate is just above the higher cost threshold, but that's a regulatory problem.

 

[sperkin]

Here is a slow Supercharger in Hawthorne. They get away calling a Supercharger because 90miles/hr is still faster than 40ish mi/hr at home.

 

[EVDRVN]

If that is at the design center (which it should be), I have pulled 118kW there. There is either an issue, you are on a shared stall, or you have an issue with the car. The M3 charges slow when cold, even at 50 so that may be an issue as well depending on your pack temp.

 

[M+K.Reeser]

Concord Ontario. 48% to 80% has taken almost an hour. My average charge rate is 114km/h which is brutal. I get 75km/h at home. Again if it’s the top end of the charge I get that I’m paying the same amount for 17kw. Not the whole charge though. It never went over 28kw and I’m paying for up to 60kw.

I am curious why you feel the need to charge with almost half your battery left?

 

[Darthbenji]

I am curious why you feel the need to charge with almost half your battery left?

Because of where I was going

 

[Saul]

I have used supercharges along the 401 from Ottawa to Woodstock with my Model 3 since June 2018.
I think i have also used the same one as you near Concord Ontario and enclosed a screenshot during that charge.
In each case i got about 750 km/hour charge during the first part of charging. I usually charge between 15% and 80%. My most costly was $14.20. All these were last summer/fall 2018 so not sure if rates increased recently. Only used it once in December 2018 and it was slower but still only cost $10.60 for an increase from about 30% to 85%.