Dumb**s alert: am I the first to drain it??

[Carcus]

Can someone tell me if the Leaf controls the amount of air flow to the battery?

i.e. if you've been tooling around in town at 20 mph avg in the no wind city environment and then jump up on the highway at 65 mph plus a headwind at 32 deg F does the Leaf have a way of closing off air flow to the battery to prevent (rapid) cold soaking?

 

[Randy]

My understanding was that the battery was sealed and there is no airflow. I thought from browsing through the service manual that there are seals mentioned. I'll look again.

There's a Nissan video floating around on YouTube that shows a test Leaf going through 3 feet of standing water. I wouldn't do that if the battery was not sealed...

 

[DarkStar]

The battery is completely sealed and slightly pressurized per the service manual.

 

[Carcus]

Ok. Thanks.

Wow. Hard to believe there's not some sort of air circulation in there.

 

[ttweed]

Range limitations aside, I'm curious to know more about the "It wouldn't Turn Off" problem.
That can't be explained away as human range approximation error.
Was the root cause of that learned?

I am very interested in hearing about that condition as well. It doesn't seem connected to running out of juice. Was there an explanation offered for that by the engineers, Kelangst?

Thx,
TT

 

[Carcus]

The battery is completely sealed and slightly pressurized per the service manual.

Not to keep beating this horse, but.....


"slightly pressurized" would mean the "pressure" (presumably air) is being introduced into the battery box from somewhere.

/"battery" as mentioned from the service manual -- means they are talking about the whole battery enclosure (?)
// plus, in the event of an emergency, the batteries will need to vent to somewhere, will they not?

///I'm not doubting that the battery box can be submerged in water (sealed from water penetration) , just having trouble with the idea that there is no air flow whatsoever. Submersible (in water) and vented (with air) don't have to be mutually exclusive.

 

[DarkStar]

The battery is completely sealed and slightly pressurized per the service manual.

Not to keep beating this horse, but.....


"slightly pressurized" would mean the "pressure" (presumably air) is being introduced into the battery box from somewhere.

/"battery" as mentioned from the service manual -- means they are talking about the whole battery enclosure (?)
// plus, in the event of an emergency, the batteries will need to vent to somewhere, will they not?

///I'm not doubting that the battery box can be submerged in water (sealed from water penetration) , just having trouble with the idea that there is no air flow whatsoever. Submersible (in water) and vented (with air) don't have to be mutually exclusive.

There is a valve that is used for testing the air-tight seal on the box, this adds a bit of pressure to the unit. I assume that it is designed to vent if excess pressure is present inside of the box. There is no regular air flow into or out of the box unless it is opened.

 

[Carcus]

The battery is completely sealed and slightly pressurized per the service manual.

Not to keep beating this horse, but.....


"slightly pressurized" would mean the "pressure" (presumably air) is being introduced into the battery box from somewhere.

/"battery" as mentioned from the service manual -- means they are talking about the whole battery enclosure (?)
// plus, in the event of an emergency, the batteries will need to vent to somewhere, will they not?

///I'm not doubting that the battery box can be submerged in water (sealed from water penetration) , just having trouble with the idea that there is no air flow whatsoever. Submersible (in water) and vented (with air) don't have to be mutually exclusive.

There is a valve that is used for testing the air-tight seal on the box, this adds a bit of pressure to the unit. I assume that it is designed to vent if excess pressure is present inside of the box. There is no regular air flow into or out of the box unless it is opened.

Ok, got it. That seals up this question (just like the battery box).

 

[garygid]

So, Nissan's fix for your LEAF not turning off?

 

[healy]

Maybe you are the first, but it happened to me too! On 2/22 I was driving back from SeaTac airport back home, with 26 "miles" on the range estimation. Trip distance was ~ 15 miles. Some driving on I-5, eco mode on, no heating (at 32 F outside temp!) and around downtown the range is down to 8 miles (still plenty to get home, which was by then 5 miles away). At the ship-canal bridge it went into turtle, I barely got off the freeway. 2 Mile from home and after about half the distance it told I would have from the airport, i.e. 13 actual miles driven, it went dead. I actually managed to drive 400 yards in turtle mode. 10:30 pm, wife and screaming kids in the car (which was blocking the right lane of a busy road), just came back from the east coast, cars zooming by and honking, several near misses, I called Nissan for help.

Their initial response:
Sure we will tow you, but it will take an hour for the tow truck to arrive and we will only tow you to the next dealership (10 miles from my home). I said, well its an electric car and arent you supposed to tow me to my home when I run out of battery? Ah, its a battery problem, do you need a boost or a jumpstart??
It was hilarious..no clue about their own product....neither the operator nor her supervisor were aware of special roadside assistance for leaf-owners.

The experience with roadside assistance was quite sobering...
What I find scarier though is this gross mismatch in estimated and actual range. Any ideas if this is normal or a bad battery?

24 kwh battery pack is not enough! It needs to be double to be practical.

 

[supercharged]

Would it be at all possible for you to let me know what happens if/when the battery in the leaf is in contact with H2O?

Thanks,
ICE man

 

[JRP3]

24 kwh battery pack is not enough! It needs to be double to be practical.

Kind of depends, my 12 kwh pack is quite practical for me. If you need almost 50 kwh then you have to buy a Tesla.

 

[mwalsh]

I am getting rather annoyed. Not at the OP, but that the OP's story has been twisted to the point that it appears many are being stranded by our LEAFs, rather that just a couple of people. Worse yet, the negativity seems to be gaining traction, and I don't personally know what to do about it, particularly in forums where there is no opportunity for rebuttal. :x

Can this negativity gain enough traction to, once again, harm the chances of EVs becoming more widely accepted? I don't know, but I'm certainly fretting over it!

 

[AndyH]

I am getting rather annoyed. Not at the OP, but that the OP's story has been twisted to the point that it appears many are being stranded by our LEAFs, rather that just a couple of people. Worse yet, the negativity seems to be gaining traction, and I don't personally know what to do about it, particularly in forums where there is no opportunity for rebuttal. :x

Can this negativity gain enough traction to, once again, harm the chances of EVs becoming more widely accepted? I don't know, but I'm certainly fretting over it!

Hang in there, Mate. There's more than 100 years of 'pro-ICE' inertia out in the world. Maybe the best thing we can do is to completely ignore the negative reporting (and not add wood to the fire) and simply keep telling the truth about our experiences with EVs. EVentually we'll overcome the FUD.

 

[Jimmydreams]

I am getting rather annoyed. Not at the OP, but that the OP's story has been twisted to the point that it appears many are being stranded by our LEAFs, rather that just a couple of people. Worse yet, the negativity seems to be gaining traction, and I don't personally know what to do about it, particularly in forums where there is no opportunity for rebuttal. :x

Can this negativity gain enough traction to, once again, harm the chances of EVs becoming more widely accepted? I don't know, but I'm certainly fretting over it!

Mike...

"A few" stranded motorists will get lots of attention when there are only a few hundred Leafs on the road. Once there are a few thousand (and growing) number of Leafs, this should quell some of the negative press. Sheer numbers (assuming the numbers of stranded drivers doesn't spike) will dilute the stories and should take care of your frettin'.

 

[TomT]

It's like a plane crash, private or commercial. There are so few that every one of them gets attention from the media. Meanwhile there are thousands of car crashes every day but they are so common that they are all but ignored.

"A few" stranded motorists will get lots of attention when there are only a few hundred Leafs on the road. Once there are a few thousand (and growing) number of Leafs, this should quell some of the negative press. Sheer numbers (assuming the numbers of stranded drivers doesn't spike) will dilute the stories and should take care of your frettin'.

 

[jcesare]

Would it be at all possible for you to let me know what happens if/when the battery in the leaf is in contact with H2O?

Thanks,
ICE man

Nothing.
The Leaf has undergone immersion testing. The battery compartment is sealed.
http://www.allcarselectric.com/blog/1047917_2011-nissan-leaf-waterboarded-for-your-safety?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+AllCarsElectric+%28All+Cars+Electric%29&utm_content=Google+Reader

 

[tbleakne]

Many posts on this forum have warned about the unreliability of the Leaf's remaining mileage estimates, so it was unwise for Kelangst and his family to rely on it for their drive home. The added concern in this thread is the evidence that under some conditions, also experienced by kapauzius, the SOC estimate also can give a false sense of security that can get one into trouble at the low end.

We can hope that Nissan improves the SOC estimation software, but it may never be as accurate as we would really like. The Leaf battery, like all Li-ion chemistries, probably has a rather flat voltage vs SOC discharge curve, with an upward curl at the top end and a downward curl at the bottom end. At the 100% level the voltage slope gives the car an accurate SOC value, but in the middle range the Leaf likely uses coulomb-counting. This suggests that partial charging to levels below 80%, which the Kelangst family did, can accumulate errors in the estimated SOC. Charging to 100% frequently to reset this estimate appears to be very prudent.

The low temperature could have affected the SOC estimate. If the temperature had dropped substantially between the charge time and the final drive, this could also skew the SOC estimate upward. Of course the car should compensate, but we don't know for sure how well it does this.

The Leaf display has a set of capacity bars in addition to the SOC bars. At some low temperature one should see the temporary loss of one of these bars, which would tell you that each of your remaining SOC bars has less actual energy. Has anyone in a cold climate seen this happen?

Clearly Nissan needs to improve the battery display; the 12 SOC bars by themselves are too crude, and the remaining mileage estimate can't know what the driver is going to do next. Nissan does have the constraint that they want to keep the interface simple enough so it does not become a distraction for the driver. Multiplying 2-digit SOC values could be distracting.

User Interface suggestion: If the driver has been given the GPS his or her destination, it will know both the remaining mileage and the terrain. If the charge is getting low for the remaining mileage, it could display a recommended maximum speed that would be efficient enough to reach the destination.

 

[LEAFer]

User Interface suggestion: If the driver has been given the GPS his or her destination, it will know both the remaining mileage and the terrain. If the charge is getting low for the remaining mileage, it could display a recommended maximum speed that would be efficient enough to reach the destination.

The CarWings *DOES* give you the warning when Estimated Range drops below distance to destination on the Nav. Happened to me this weekend. But something else happened that's just plain ridiculous, and which I will report about in next couple of days. It's not so much a problem with the LEAF or CarWings or the Estimated Range, but the Nav under certain conditions. (Don't mean to be mysterious, but I need to take some time getting my "tone" and data together.)

 

[JRP3]

Many posts on this forum have warned about the unreliability of the Leaf's remaining mileage estimates, so it was unwise for Kelangst and his family to rely on it for their drive home. The added concern in this thread is the evidence that under some conditions, also experienced by kapauzius, the SOC estimate also can give a false sense of security that can get one into trouble at the low end.

We can hope that Nissan improves the SOC estimation software, but it may never be as accurate as we would really like. The Leaf battery, like all Li-ion chemistries, probably has a rather flat voltage vs SOC discharge curve, with an upward curl at the top end and a downward curl at the bottom end. At the 100% level the voltage slope gives the car an accurate SOC value, but in the middle range the Leaf likely uses coulomb-counting. This suggests that partial charging to levels below 80%, which the Kelangst family did, can accumulate errors in the estimated SOC. Charging to 100% frequently to reset this estimate appears to be very prudent.

Actually in another post AndyH makes a good argument that the LiMn chemistry in the LEAF has a steeper curve throughout it's capacity and that balancing can take place anywhere along the curve.
http://www.mynissanleaf.com/viewtopic.php?f=31&t=2735&start=50