LEAF 2 : What we know so far (2018 or later?)

[dgpcolorado]

try QC'ing at 125 amps up to 85%. I see 10 TBs every day.... like right now but then again, its not all that cool today

Exactly the point I was trying to make. Even that relatively slow "fast charge" speed is likely damaging the battery. The battery won't be any cooler in a warmer climate or when driving at 80 mph, which is what one does on long road trips in the many states that have that have high speed limits. Add in 100 kW Supercharging and it figures to be damaging to an uncooled battery. (By the way, when driving and Supercharging like this, the Tesla cooling system is going full blast when one pulls in to a Supercharger Station and it keeps going for quite some time, and again periodically during the charging session.)

Here is the question to all the people who hope someday, somehow Leaf will support Tesla SC.

Its very clear it would be advantageous to Leaf owners. But what is in it for Tesla ? Afterall with Model 3 the fear is the SCs would get heavily clogged.

Exactly why Tesla might be interested in a venture to expand SC infrastructure, sooner rather than later. Having a manufacturer the size of Nissan join would be a strong move towards SuperCharge becoming the de-facto standard.

It would make sense only if Leaf pays so much money to Tesla that Tesla can build more SCs that will lessen the expected clogging - even while adding more cars (Leafs). That can't be cheap - and Nissan would have to pass on that cost, and given the target market of Leafs - few would be willing to pay that cost....

As the saying goes, "Skate to where the puck is going to be". Nissan's EV program won't end with LEAF, nor is their target market static. Enhanced distance facilities expand the target, and ChaDeMo just isn't going to win the standards war -- a significant roadblock. Cost? Yes, but it doesn't have to be amortized over just LEAF production. Again, take the long view. Tesla and Nissan cooperating in such a fashion could be synergistic. I.e., double the size of the SC network, and the attractiveness to both Tesla and Nissan owners could grow by much more than a factor of 2.

I expect that Tesla would be pleased to have Nissan or another manufacturer join in the Supercharger network for just the reasons you (and others) state. But the cars would have to be able to fast charge at Supercharger speeds without damage and the LEAF just isn't there yet. With current battery technology I don't think any cars can charge at Supercharger speeds without some sort of TMS. Slow charging at 50 kW or less just clogs up the stalls and would not be practical (or allowed by Tesla). Hence, my position that Nissan isn't likely to join the Supercharger network unless the coming cars have TMS.


So far as the fast charging "standards war" goes, I think that the Tesla version may be replaced eventually by CCS; that already seems to be happening in Europe. Tesla's is more elegant, to put it mildly, but with so many other manufacturers putting their weight behind CCS it seems likely to win out in the end. Or, perhaps, something better will come along (although I have little patience for inductive charging — favored by some — due to inefficiency).

 

[Nubo]

...I don't think any cars can charge at Supercharger speeds without some sort of TMS. Slow charging at 50 kW or less just clogs up the stalls and would not be practical (or allowed by Tesla). Hence, my position that Nissan isn't likely to join the Supercharger network unless the coming cars have TMS. ...

Max charge rate is a function of pack capacity. It's a diffusion process, with the Lithium ions looking for "places to sit", like a giant game of Musical Chairs. Heat happens when the number of available chairs gets too low, and the ions start "bumping into each other", to continue the analogy. That's when tapering begins.

So, if a 24kWH pack can make reasonable use of 50A (2C rate), a 60kWH pack can easily make use of a 100A station (1.66C rate). It has more diffusion capacity. 2C rate on a 40kWH pack is 80A. And today's pack sizes aren't tomorrow's pack sizes. Charging infrastructure is a long-term investment. I wouldn't predicate Nissan's future plans on the performance characteristics of the Gen1 LEAF.

As for the standards war, I reckon it will be won by whoever implements a dependable widely-available and useful network. So far Tesla seem to be the ones really going for it other than maybe VW, and that only because their feet are being held to the fire. Meaning they probably won't do it with any sense.

 

[GetOffYourGas]

I understand there is no POS at the units, but they obviously have a way to track and limit use for the incoming 3's, so somehow you get a card with an ID on it linked a payment option and you're set. Seems pretty straightforward to me.

Model 3 have no use limits and there is no card. Model 'S' owners paid $2000 for optional SC access. Would you like to do the same ?

It was my understanding that Model 3 drivers got 400kWh/year and then had to pay per kWh thereafter. While you're right that there are no limits, Tesla absolutely tracks usage. It's done directly with the car via the supercharging cable. Hence, no card.

I would gladly pay $2k for unlimited supercharger access, regardless of charge rate (assuming >50kW), provided the car can easily make the trip between SC locations.

 

[SageBrush]

So, if a 24kWH pack can make reasonable use of 50A (2C rate), a 60kWH pack can easily make use of a 100A station (1.66C rate). It has more diffusion capacity. 2C rate on a 40kWH pack is 80A. And today's pack sizes aren't tomorrow's pack sizes. Charging infrastructure is a long-term investment. I wouldn't predicate Nissan's future plans on the performance characteristics of the Gen1 LEAF.

I don't think your arithmetic is right.

EVs today have packs that are ~ 360v nominal, so
A 24 kWh pack has 24000/360 = 66.66 Ahr capacity
A 60 kWh pack has 60000/360 = 166.6 Ahr capacity

A 100A station is then charging a 60 kWh pack at 0.6 C

 

[SageBrush]

I understand there is no POS at the units, but they obviously have a way to track and limit use for the incoming 3's, so somehow you get a card with an ID on it linked a payment option and you're set. Seems pretty straightforward to me.

Model 3 have no use limits and there is no card. Model 'S' owners paid $2000 for optional SC access. Would you like to do the same ?

It was my understanding that Model 3 drivers got 400kWh/year and then had to pay per kWh thereafter. While you're right that there are no limits, Tesla absolutely tracks usage. It's done directly with the car via the supercharging cable. Hence, no card.

I would gladly pay $2k for unlimited supercharger access, regardless of charge rate (assuming >50kW), provided the car can easily make the trip between SC locations.

It is not yet clear what plan Tesla will offer Model 3 owners for SC use. One rumor said 1000 kWh lifetime free, then rates as already published.

Tesla tracks usage, but that was my undeclared point. The SC and the Tesla car are tightly integrated. There is a lot more to it than a Tesla compatible adapter in your case. So your desire to plug your LEAF into a SC entails paying Tesla enough to expand the network commensurately and paying Nissan to make your car SC compatible. LEAF owners cannot choose SC access individually as a technical matter ... even if Tesla was open politically to the idea which is silly from a business perspective.

I value the SC highly too, so I'm buying a Model 3 for our long distance driving instead of a competing EV.

 

[Nubo]

So, if a 24kWH pack can make reasonable use of 50A (2C rate), a 60kWH pack can easily make use of a 100A station (1.66C rate). It has more diffusion capacity. 2C rate on a 40kWH pack is 80A. And today's pack sizes aren't tomorrow's pack sizes. Charging infrastructure is a long-term investment. I wouldn't predicate Nissan's future plans on the performance characteristics of the Gen1 LEAF.

I don't think your arithmetic is right.

EVs today have packs that are ~ 360v nominal, so
A 24 kWh pack has 24000/360 = 66.66 Ahr capacity
A 60 kWh pack has 60000/360 = 166.6 Ahr capacity

A 100A station is then charging a 60 kWh pack at 0.6 C

Ah, yes you're right. But the ratios still hold; a 60kWH pack is still being charged a lower C rate at 100A than a 24kWH pack at 50A.

 

[SageBrush]

So, if a 24kWH pack can make reasonable use of 50A (2C rate), a 60kWH pack can easily make use of a 100A station (1.66C rate). It has more diffusion capacity. 2C rate on a 40kWH pack is 80A. And today's pack sizes aren't tomorrow's pack sizes. Charging infrastructure is a long-term investment. I wouldn't predicate Nissan's future plans on the performance characteristics of the Gen1 LEAF.

I don't think your arithmetic is right.

EVs today have packs that are ~ 360v nominal, so
A 24 kWh pack has 24000/360 = 66.66 Ahr capacity
A 60 kWh pack has 60000/360 = 166.6 Ahr capacity

A 100A station is then charging a 60 kWh pack at 0.6 C

Ah, yes you're right. But the ratios still hold; a 60kWH pack is still being charged a lower C rate at 100A than a 24kWH pack at 50A.

A Supercharger reaches ~ 300 Amps.

dgpcolorado's point is this: even with TMS, a Tesla throttles down to around 0.9 C early on in the charge session. Without cooling during the charge a battery would over-heat.

By the way: dgp is a retired EE Prof. Thought you might want to know

 

[Nubo]

A Supercharger reaches ~ 300 Amps. ...

By the way: dgp is a retired EE Prof. Thought you might want to know

Extant superchargers deliver a max of 120kW per car.

I think I made a valid point regarding charge rate scaling proportional to pack capacity, and that 24kWH LEAF, TODAY, can make us of a 50A QC.

If you disagree perhaps you could make a logical refutation, instead of trying to co-opt someone else's credentials.

 

[SageBrush]

By the way: dgp is a retired EE Prof. Thought you might want to know

I think I made a valid point regarding charge rate scaling proportional to pack capacity, and that 24kWH LEAF, TODAY, can make us of a 50A QC.
If you disagree perhaps you could make a logical refutation, instead of trying to co-opt someone else's credentials.

I'm no co-opting anything or anybody; I'm suggesting that you might want to be better informed before taking on dgp. But only if care to not look the fool.

Your 'valid' point is based on ignorance of electricity units. A 50A "QC" is around 18 kW.
Superchargers go up to 145 kW, although they are currently limited to 120 kW in current model Teslas.

 

[Nubo]

By the way: dgp is a retired EE Prof. Thought you might want to know

I think I made a valid point regarding charge rate scaling proportional to pack capacity, and that 24kWH LEAF, TODAY, can make us of a 50A QC.
If you disagree perhaps you could make a logical refutation, instead of trying to co-opt someone else's credentials.

I'm no co-opting anything or anybody; I'm suggesting that you might want to be better informed before taking on dgp. But only if care to not look the fool.

Your 'valid' point is based on ignorance of electricity units. A 50A "QC" is around 18 kW.
Superchargers go up to 145 kW, although they are currently limited to 120 kW in current model Teslas.

18kW scaled up from servcing 24kWH LEAF to 60kWH LEAF is 45kW. That's a respectable rate. Just as one can get about 80% of charge in 30 minutes at a 50A station with 24kWH LEAF, one could get a similar charge in 30 minutes at a supercharger with 60kWH LEAF. And that is, after all, what Tesla encourages Model S owners to do -- 30 minute charge and move on, instead of waiting through the inevitable taper.

 

[SageBrush]

I think I made a valid point regarding charge rate scaling proportional to pack capacity, and that 24kWH LEAF, TODAY, can make us of a 50A QC.
If you disagree perhaps you could make a logical refutation, instead of trying to co-opt someone else's credentials.

I'm no co-opting anything or anybody; I'm suggesting that you might want to be better informed before taking on dgp. But only if care to not look the fool.

Your 'valid' point is based on ignorance of electricity units. A 50A "QC" is around 18 kW.
Superchargers go up to 145 kW, although they are currently limited to 120 kW in current model Teslas.

18kW scaled up from servcing 24kWH LEAF to 60kWH LEAF is 45kW. That's a respectable rate. Just as one can get about 80% of charge in 30 minutes at a 50A station with 24kWH LEAF, one could get a similar charge in 30 minutes at a supercharger with 60kWH LEAF. And that is, after all, what Tesla encourages Model S owners to do -- 30 minute charge and move on, instead of waiting through the inevitable taper.

30 minutes at an untapered 18 kW is ~ 8 kWh into the battery. That is no where near 80% charge for a 24 kwh pack. Try 33%

Anyway, you are forgetting two points:
1. The 18 kW is a peak power in a 50A "QC" station, and in a LEAF is tapered during a charging session from the peak.
2. The SC reported rates are in TMS packs that are liquid cooled.

Compare apples to apples and the same conclusion results: A passive cooled pack will never be allowed to hook up to a SC. It will either be dog slow and degrade the performance of the SC network, or be dangerous.

 

[Nubo]

You are forgetting two points:
1. The 18 kW is a peak power in a 50A "QC" station, and in a LEAF is tapered during a charging session from the peak.
2. The SC reported rates are in TMS packs that are liquid cooled.

Compare apples to apples and the same conclusion results: A passive cooled pack will never be allowed to hook up to a SC. It will either be dog slow and degrade the performance of the SC network, or be dangerous.

I'm not forgetting anything, I'm making a very simple point. With existing LEAF, you can get a majority of range in about 30 minutes time. Lack of TMS notwithstanding. Demonstrated ability. Do you deny this?

This ability should hold if capacity increases, as long as the station can supply the necessary power. 30 minutes is 30 minutes. That's not "dog slow", it's a typical Tesla use case.

 

[edatoakrun]

Since MNL LEAF moderators all seem to be on vacation, can we end the off-topic discussion, after only the last ~40 comments?

In summary, TSLA does not seem interested in selling any more tickets on its Titanic DC network, and only the foolish BEV owner or BEV manufacturer would pay in advance for lifetime charging, when the offer is limited to the (possibly very short) lifetime of TSLA.

On-topic, we still have no idea what kW rate the Gen two LEAF pack will be allowed to accept, and for how long before tapering.

And for many years to come, the vast majority of public DC sites will probably be limited to ~50 kW or less (by design limits or due to excessive demand charges) anyway.

 

[internalaudit]

So bigger battery (keeping everything equal/constant) almost always equates to less degradation and slightly faster charging time?

 

[GetOffYourGas]

On-topic, we still have no idea what kW rate the Gen two LEAF pack will be allowed to accept, and for how long before tapering.

And for many years to come, the vast majority of public DC sites will probably be limited to ~50 kW or less (by design limits or due to excessive demand charges) anyway.

http://insideevs.com/new-leaf-150-kw-dc-fast-charging-via-dbt/

Older news (~2 months ago). But tangentially related to the Leaf 2. If Nissan is working to help install 150kW chargers, it implies that something better than 50kW charging is coming. I am somewhat hopeful that the Leaf will offer a 60kWh battery with 100kW charging no later than the MY19. As Nubo pointed out, this is less stressful than charging a 24kWh battery at 50kW.

IMO, once you hit 150kW, you really don't need to go much higher. That's 50kWh in a 20-minute stop. Even if only 40kWh gets in the battery, it's 160 miles at 4 miles/kWh (2.5 hours of driving). The key then is to get more of the chargers out there, rather than have fewer that are really fast.

Nissan seems to understand that infrastructure is very important for EVs. They are doing more on that front than anyone other than Tesla. So if they are pushing 150kW chargers, that is a good sign.

First deliveries of the 150 kW units are expected in September – which is also when the new 2018 LEAF debuts in Tokyo – on September 6th (which is the 5th in most other places).

So I'm not sure I agree with your conclusion that "for many years to come, the vast majority of public DC sites will probably be limited to ~50 kW or less"

 

[SageBrush]

IMO, once you hit 150kW, you really don't need to go much higher.

I can't tell from the charging station specs if they mean up to 150 kW per car or per station. If it is per station and always split equally then they are talking about 75 kW per car at peak rate. That is still quite nice but not up to SC standards.

And in any case a passive cooled battery would never survive anywhere near those rates for any length of time.

 

[GetOffYourGas]

IMO, once you hit 150kW, you really don't need to go much higher.

I can't tell from the charging station specs if they mean up to 150 kW per car or per station. If it is per station and always split equally then they are talking about 75 kW per car at peak rate. That is still quite nice but not up to SC standards.

And in any case a passive cooled battery would never survive anywhere near those rates for any length of time.

Interesting. I had simply assumed that they meant 150kW per car, but I guess they don't explicitly state that. The author of that article seems to assume 150kW/car too.

SC standards will improve over time of course. But I don't think that's the sole measure of usefulness. Going much above 100kW is more about marketing than actual useful performance, IMO. I'd rather see a dozen 100kW ports than 4x 300kW ports personally.

 

[LeftieBiker]

Jesus, enough already! You want to wonk over technical specs of charging stations, make a topic for it!

 

[SageBrush]

IMO, once you hit 150kW, you really don't need to go much higher.

I can't tell from the charging station specs if they mean up to 150 kW per car or per station. If it is per station and always split equally then they are talking about 75 kW per car at peak rate. That is still quite nice but not up to SC standards.

And in any case a passive cooled battery would never survive anywhere near those rates for any length of time.

Interesting. I had simply assumed that they meant 150kW per car, but I guess they don't explicitly state that. The author of that article seems to assume 150kW/car too.

SC standards will improve over time of course. But I don't think that's the sole measure of usefulness. Going much above 100kW is more about marketing than actual useful performance, IMO. I'd rather see a dozen 100kW ports than 4x 300kW ports personally.

The trick is to maintain the high rates for 100 - 150 miles worth of added range. When it becomes possible, a 150 kW stream in a 4 miles/kWh car will require stops of 12 minutes every two hours or so. There is no doubt that active cooling is required since about 10 kW of heat will need to be removed during the charge.

 

[edatoakrun]

On-topic, we still have no idea what kW rate the Gen two LEAF pack will be allowed to accept, and for how long before tapering.

And for many years to come, the vast majority of public DC sites will probably be limited to ~50 kW or less (by design limits or due to excessive demand charges) anyway.

...If Nissan is working to help install 150kW chargers, it implies that something better than 50kW charging is coming...

Sure...but

Nissan has already helped to install hundreds of dual-use CHADeMO/ CCS chargers, even though it does not use CCS itself.

A number of 90-100 kWh pack BEVs will hit the market next year, and they will charge at over 50 kW at public sites, even if the Gen two LEAF does not.

="GetOffYourGas"

...I'm not sure I agree with your conclusion that "for many years to come, the vast majority of public DC sites will probably be limited to ~50 kW or less"...

As of today, there are reported to be 2,215 CHAdeMO sites in the USA, ALL of them 50 kW or less, AFAIK.

https://www.chademo.com/

Many more ~50 kW chargers than ~150 kW chargers will be installed in the near future, and it will be decades before the thousands of them are all replaced with higher kW units.

Everyone should take notice that higher kW chargers require higher hardware costs AND higher energy costs per kWh delivered.

So if the charge per kWh delivered is constant for different delivery rates, those BEV drivers who want only lower kW rates will be effectively subsidizing those BEV drivers who demand higher-speed charging.

Having rock-solid-dependable 50 kW sites every few miles along major highways exactly where you want them, so you can stop when your charge is nearly entirely depleted, rather than being forced to charge where a site is available, even when you have 20 or 30 miles of range left, is going to be a much more significant development in increasing the convenience of charging on long trips than faster charge rates, IMO.

...When it becomes possible, a 150 kW stream in a 4 miles/kWh car will require stops of 12 minutes every two hours or so. There is no doubt that active cooling is required since about 10 kW of heat will need to be removed during the charge.

Is that statement based on any authoritative source?