Nissan LEAF - It IS the car for me!

[evnow]

I don't think the SAE gives 2 S***S about what is already installed. L3 Chademo will only be in the Western US, in 4 or so states + TN.

If Nissan can rope in Ford, Toyota & Tesla - it will be a done deal.

Most probably SAE will approve Chademo and one more home grown standard. Everyone will just ignore the new std and use Chademo.

 

[DaveEV]

I didn't do that because I know these accessories are supposed to run on the 12v battery and didn't know if they would make any difference to the pack charge during a run where the 12v probably had a good part of it's own charge.

With the car on, the 12V system is in essence running off the big pack just like the Prius. The state of charge of the 12V battery will affect the draw on the main pack, since it will charge the 12V battery with the car on. So unless the 12V battery is overcharged (impossible, since a 12V battery will not exceed the 14.4V that a typical car system runs at when on even when fully charged), all your 12V accessories are running off the big pack while the car is on.

If the traction control is programmed to not allow any wheel spin, you could easily get another half second with a good launch, putting it in the high 8 second range.

On my test drive, I floored it from a stop on a right hand turn and got a bit of wheel-spin from the inside tire. I didn't explicitly turn off TC and I doubt my co-driver did (especially since it was raining earlier in the day), so I'm guessing it will allow a bit of wheel spin.

Don't forget the AC was on. Turning it off might give you that other second. :?:

I doubt it - the motor is rated at 80 kW and the battery is rated at 90 kW - I suspect this was on purpose since it appears that HVAC + other will draw nearly 10 kW. Also, from mwalsh's screenshots it doesn't appear that the AC was working very hard and only pulling about 600 W. It would be nice if they let the motor pull more than 80 kW if the rest of the car isn't using the spare power, though.

 

[DaveEV]

I don't think the SAE gives 2 S***S about what is already installed. L3 Chademo will only be in the Western US, in 4 or so states + TN.

If Nissan can rope in Ford, Toyota & Tesla - it will be a done deal.

Most probably SAE will approve Chademo and one more home grown standard. Everyone will just ignore the new std and use Chademo.

I have to admit that it does make sense to try to integrate the L2 and L3 ports into one connector...

 

[SanDust]

the motor is rated at 80 kW and the battery is rated at 90 kW

Unlike an engine where the rated output is a theoretical maximum that you aren't likely to see in practice, a motor can produce several times its rated output for short periods of time. You have to assume the battery is the limiting factor.

 

[DaveEV]

the motor is rated at 80 kW and the battery is rated at 90 kW

Unlike an engine where the rated output is a theoretical maximum that you aren't likely to see in practice, a motor can produce several times its rated output for short periods of time. You have to assume the battery is the limiting factor.

Right - and similarly, the battery should also be able to sustain higher loads for short periods of time.

With a capacity of 24 kW and max power limited to 90 kW - that is approximately a rate of 4C which is not all that high.

Many lithium batteries can sustain discharge rates of 20C for short periods of time - that would mean it might be possible for the Leaf batteries to supply 480 kW.

Of course, high discharge rates reduce efficiency, generate heat and increase the rate at which the battery degrades...

Edit: Doing some digging it appears that the AESC modules are good for about 1000 W / kg - each of the 48 modules weight about 3.8 kG, for a total of 182 kG - that would indicate that the Leaf battery should be able to handle about 180 kW of power without issue.

 

[cdub]

I have to admit that it does make sense to try to integrate the L2 and L3 ports into one connector...

That won't work because the L3 port bypasses the charger and goes straight to the battery. That's why there is a second port.

With an L3 charging... the charger is in the charging unit and not in the car. That's why it would be a simple port swap if the standards change.

 

[smkettner]

I have to admit that it does make sense to try to integrate the L2 and L3 ports into one connector...

That won't work because the L3 port bypasses the charger and goes straight to the battery. That's why there is a second port.

With an L3 charging... the charger is in the charging unit and not in the car. That's why it would be a simple port swap if the standards change.

Unless the battery grows significantly more power through the existing L2 and charger would almost make L3 unneeded.

 

[evnow]

With a capacity of 24 kW and max power limited to 90 kW - that is approximately a rate of 4C which is not all that high.
...
Edit: Doing some digging it appears that the AESC modules are good for about 1000 W / kg - each of the 48 modules weight about 3.8 kG, for a total of 182 kG - that would indicate that the Leaf battery should be able to handle about 180 kW of power without issue.

Right. The Battery is very conservatively rated. Expect the same pack in Infinity EV to make it work like a sports car.

 

[DaveEV]

I have to admit that it does make sense to try to integrate the L2 and L3 ports into one connector...

That won't work because the L3 port bypasses the charger and goes straight to the battery. That's why there is a second port.

With an L3 charging... the charger is in the charging unit and not in the car. That's why it would be a simple port swap if the standards change.

The preliminary plans are to essentially combine the PINs so that the single plug will work either way... they are still working on it. The design should be finalized next year, I think.

Here's a link describing the controversy:

http://www.examiner.com/green-transportation-in-national/the-controversy-fast-charging-for-electric-vehicles-plugin-2010

There was a thread here that talked about it, too, but I can't find it right now...

 

[cdub]

The preliminary plans are to essentially combine the PINs so that the single plug will work either way... they are still working on it. The design should be finalized next year, I think.

Yes but I heard a Nissan rep say that when you order the L3 charging port the battery and the car is wired entirely differently and that the L3 port is basically a direct connection to the charger bypassing the 3.3 onboard charger.

This is why the port cannot be added later.

 

[mitch672]

The preliminary plans are to essentially combine the PINs so that the single plug will work either way... they are still working on it. The design should be finalized next year, I think.

Yes but I heard a Nissan rep say that when you order the L3 charging port the battery and the car is wired entirely differently and that the L3 port is basically a direct connection to the charger bypassing the 3.3 onboard charger.

This is why the port cannot be added later.

we where talking about what the SAE will do for a L3 DC fast Charging standard, this has nothing to do with the Nissan Leaf.

The Nissan Leaf V1 might never be able to use this new standard, since it was designed before the standard was issued.
Especially if it is going to be a single, newly designed connector that handles AC and DC via the same pins, but has signalling that tells it how to route the power (onboard charger or direct to the batteries, done via relays or SCRs no doubt)

get it?

 

[mwalsh]

the L3 port is basically a direct connection to the charger

I assume you meant to say battery there? If so, true statement...DC Fast Charge is a direct connection to the battery pack.

 

[cdub]

the L3 port is basically a direct connection to the charger

I assume you meant to say battery there? If so, true statement...DC Fast Charge is a direct connection to the battery pack.

Yes sorry. Direct connection to the battery.

 

[SanDust]

Of course, high discharge rates reduce efficiency, generate heat and increase the rate at which the battery degrades...

Yes. All reasons to limit the discharge rate.

 

[smkettner]

The L2 evse signal could just as easy tell the car to flip a relay and connect direct to the battery as higher voltage DC is available direct to the battery.

 

[tps]

Especially if it is going to be a single, newly designed connector that handles AC and DC via the same pins, but has signalling that tells it how to route the power (onboard charger or direct to the batteries, done via relays or SCRs no doubt)

get it?

The proposed SAE "combined" connector drawing I've seen does not use the same pins for AC and DC; the top part of the connector looks like the current J1772, but below that it has 2 very large pins dedicated to the high-current DC. Apparently the lower current AC pins are not used when DC fast charging. I think they also throw in a couple small signal pins for the CAN bus. But the idea is that the current J1772 connector will plug into the top part of the new SAE "combined" connector.

Personally, I hope LEAF's current J1772 / JARI pair becomes the defacto standard; the new SAE "combined" connector looks ugly to me.

 

[mitch672]

Especially if it is going to be a single, newly designed connector that handles AC and DC via the same pins, but has signalling that tells it how to route the power (onboard charger or direct to the batteries, done via relays or SCRs no doubt)

get it?

The proposed SAE "combined" connector drawing I've seen does not use the same pins for AC and DC; the top part of the connector looks like the current J1772, but below that it has 2 very large pins dedicated to the high-current DC. Apparently the lower current AC pins are not used when DC fast charging. I think they also throw in a couple small signal pins for the CAN bus. But the idea is that the current J1772 connector will plug into the top part of the new SAE "combined" connector.

Personally, I hope LEAF's current J1772 / JARI pair becomes the defacto standard; the new SAE "combined" connector looks ugly to me.

even better. my guess is once this is rattified by the SAE, the 2012 or 2013 MY Leaf will use the new standard, and the older Leafs won't be retrofitted, there really is no need to... they can stay Chademo/J-1772 on separate connectors, since the infrastructure to support them will be commonplace in the AREAs they are being sold (5 initial roll out states)
the rest of the country could certainly be different, and DC fast charging may take years to deploy in other areas, as the political compass will have shifted again by them, and who knows if more "EV Project" funding will ever be seen again for the rest of the country. It may take commercialization of L3 chargers, as in placed in gas stations, to get them deployed in other parts of the country.

 

[evnow]

I have to admit that it does make sense to try to integrate the L2 and L3 ports into one connector...

Yes it does. But it makes more sense to quickly develop the infrastructure and reduce our dependence on oil. Compared to this broader goal, the one connector is insignificant.

 

[tps]

I have to admit that it does make sense to try to integrate the L2 and L3 ports into one connector...

Actually it doesn't make as much sense to me because the new proposed SAE "combiined" connector essentiallly adds a separate set of pins in a larger housing. Even the SAE made the concession that the pins in the existing J1772 connector were not suitable for DC fast charging, so they are proposing a new, larger connector outline which contains extra pins for the DC and CAN connections.

 

[mwalsh]

I've got some videos for you, boys and girls. Now, the first thing you'll notice is that I'm a really bad videographer. Then you'll notice there is no audio...my co-driver wasn't comfortable with me sharing his thoughts, so I cut the audio. Basically what I'm showing you is drive one of the event, with a focus on range.

Anyway, not the best video. But I hope it will provide some additional insights!

Segment one:

Us on a freeway leg of about 1.5 miles, about 16 miles into the drive. I have just taken the role of passenger/navigator.

So remember....we started out with 90 miles range, which dropped almost immediately to 81 miles as we were pulling away from the Nissan HQ. The start of the video shows us with 77 miles of range left and at this point we're about 16 miles into the drive. Are you doing the math?

Notice what rapid acceleration to freeway speeds does to the Instant meter on the display...YIKES! And I now notice too that we lost quite a bit of range doing that (down to 66 miles from 77 at the worst of it). But you can also see that once we settle down to cruise, miles per kWh as shown by the Instant meter seems to be more dependent on terrain when trying to maintain a steady speed than anything else. Remember that the Average for this run did not work because we didn't know we had to reset it, so it'll show 5.1 miles per kWh the entire time. Towards the end of this segment we slow down, exit the freeway, and come to a complete stop and we gain a few miles of range back, thanks to regen.

[youtube]http://www.youtube.com/watch?v=_cgTZoEuOuc[/youtube]

Segment two:

We'd just finished our second 0-60 run. No video of that because I didn't have the time to properly juggle both camera and stopwatch. But do notice that we haven't impacted our range by doing the 0-60 at all. Note too what we're getting on the Instant at speeds in the high 40mph to mid 50mph range.....it's pegged at (at least) 8 miles per kWh and we're actually clawing range back! At this point we're about 20 miles into the drive and are back up to 76 miles of range. Segment two also gives you a brief opportunity to see the rolling country roads we were driving and, when I switch to the Energy Usage screen, you also get a chance to see how much the motor has to work (or not, when it kicks into regen) to maintain speed on them.

[youtube]http://www.youtube.com/watch?v=0ne3Tw_OqLo[/youtube]

Segment three:

Is pretty much more of the same, though I see my partner gets a bit frisky again towards the end of it (and once again see what happens to the Instant meter) but then levels off again as soon as he gets to 65mph. Watch too what happens to range though as he shifts into ECO just the once, to check it out - range immediately jumps from 72 miles to 78 miles temporarily, and then comes down to 70 miles when he takes it out of ECO again. At which point I run out of memory card (WHY does that always happen to me!).

[youtube]http://www.youtube.com/watch?v=vVRK59H2Emo[/youtube]