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

[gadyamit]

Electric cars must have longevity this should and have been the key!!!
specially in the years since the first Leaf ONE came to existance.

Technology expert say that a good (better then the Leaf) colling system is a must, I'm sure the Leaf 2 will do what need to be done and what is now de-facto standard for electric car i.e. liquide colling system.
We have seen the result and next generation should solve it. As much as I know now-days a good cooling system is more or less of the shelf product...

 

[DNAinaGoodWay]

At a minimum, with a 60 kWh pack, and coming DCFC at 100 kW or more, some kind of cooling will be needed, if only while charging.

 

[ydnas7]

At a minimum, with a 60 kWh pack, and coming DCFC at 100 kW or more, some kind of cooling will be needed, if only while charging.

nope

 

[DNAinaGoodWay]

Succinct, if nothing else.

 

[dhanson865]

At a minimum, with a 60 kWh pack, and coming DCFC at 100 kW or more, some kind of cooling will be needed, if only while charging.

nope

Needed yes, provided by Nissan, not likely?

We wouldn't have a 760+ page thread on heat related battery degradation if heat wasn't an issue.

 

[WetEV]

Electric cars must have longevity this should and have been the key!!!
specially in the years since the first Leaf ONE came to existance.

Technology expert say that a good (better then the Leaf) colling system is a must,

Why?

Battery chemistry varies in how much heat will reduce capacity. If changes to chemistry can provide acceptable life in hot places, then the reduced cost and energy draw of not having a thermal management system is clearly better everywhere.

Even if the chemistry isn't much improved from the Leaf, I'd rather buy a car without thermal management, as my battery pack rarely gets warm enough that the cooling system would actually reduce the temperature.

 

[GetOffYourGas]

Electric cars must have longevity this should and have been the key!!!
specially in the years since the first Leaf ONE came to existance.

Technology expert say that a good (better then the Leaf) colling system is a must,

Why?

Battery chemistry varies in how much heat will reduce capacity. If changes to chemistry can provide acceptable life in hot places, then the reduced cost and energy draw of not having a thermal management system is clearly better everywhere.

Even if the chemistry isn't much improved from the Leaf, I'd rather buy a car without thermal management, as my battery pack rarely gets warm enough that the cooling system would actually reduce the temperature.

While I agree with your conclusion, your supposition is based on potential future technology. Today's batteries do not provide acceptable life in hot climates on their own. Today's TMS systems provide a viable solution to that problem.

I think we would all prefer to buy a car without TMS, provided it works for us in our climate. Unfortunately for you, the Leaf is a world car. The same design is sold and operated in almost all climates around the world, and not just the gentle PNW.

Frankly, I too would buy another Leaf without TMS. The degradation is manageable in upstate NY. It sometimes gets hot in the summer, but never for more than a week at a time. And even then, it is much cooler overnight. With a 24kWh battery, I can go ~3 days between charging (in summer, when I don't need heat). With a 60kWh battery, I could easily ride out the longest hot spell in Syracuse.

I would rather see Nissan design the next Leaf for the lowest common denominator. I hope it sells well across the globe, and finds many happy owners in all climates.

 

[WetEV]

Frankly, I too would buy another Leaf without TMS. The degradation is manageable in upstate NY. It sometimes gets hot in the summer, but never for more than a week at a time. And even then, it is much cooler overnight. With a 24kWh battery, I can go ~3 days between charging (in summer, when I don't need heat). With a 60kWh battery, I could easily ride out the longest hot spell in Syracuse.

I would rather see Nissan design the next Leaf for the lowest common denominator. I hope it sells well across the globe, and finds many happy owners in all climates.

I'd rather see TMS as an option that I don't have to buy, even if was needed in hot climates.

 

[GetOffYourGas]

I'd rather see TMS as an option that I don't have to buy, even if was needed in hot climates.

Fair enough. That would be great, and I would opt out of the TMS.

I don't suspect Nissan (or anyone) will offer TMS as an option, though. So far, all TMS designs have been highly integrated with the battery itself. And the cost is probably mostly upfront NRE (non-recurring engineering) rather than the added price on each vehicle. Nobody has hinted at offering an optional TMS now or in the future.

 

[LTLFTcomposite]

^ Think about the warranty too. Some guy buys (or leases) a car in Seattle, then it finds its way to Tucson. Even today the LEAF 30kwh has an eight year capacity warranty; that's a lot of time for a car to move around.

 

[WetEV]

I'd rather see TMS as an option that I don't have to buy, even if was needed in hot climates.

Fair enough. That would be great, and I would opt out of the TMS.

I don't suspect Nissan (or anyone) will offer TMS as an option, though. So far, all TMS designs have been highly integrated with the battery itself. And the cost is probably mostly upfront NRE (non-recurring engineering) rather than the added price on each vehicle. Nobody has hinted at offering an optional TMS now or in the future.

TMS takes energy to run, adds mass to car, and would decrease battery life in cool areas.

I'd like, somehow, to have a choice to avoid one.

 

[GetOffYourGas]

I'd rather see TMS as an option that I don't have to buy, even if was needed in hot climates.

Fair enough. That would be great, and I would opt out of the TMS.

I don't suspect Nissan (or anyone) will offer TMS as an option, though. So far, all TMS designs have been highly integrated with the battery itself. And the cost is probably mostly upfront NRE (non-recurring engineering) rather than the added price on each vehicle. Nobody has hinted at offering an optional TMS now or in the future.

TMS takes energy to run, adds mass to car, and would decrease battery life in cool areas.

I'd like, somehow, to have a choice to avoid one.

I understand your argument. Moreover, I agree and would also choose to forgo a TMS. All I'm saying is that I doubt Nissan (or any other OEM) is going to give us that choice.

 

[dhanson865]

I'd rather see TMS as an option that I don't have to buy, even if was needed in hot climates.

Fair enough. That would be great, and I would opt out of the TMS.

I don't suspect Nissan (or anyone) will offer TMS as an option, though. So far, all TMS designs have been highly integrated with the battery itself. And the cost is probably mostly upfront NRE (non-recurring engineering) rather than the added price on each vehicle. Nobody has hinted at offering an optional TMS now or in the future.

TMS takes energy to run, adds mass to car, and would decrease battery life in cool areas.

I'd like, somehow, to have a choice to avoid one.

If it is programmed not to come on and waste power when the temp is below the threshold for heat degradation it won't decrease battery life at all in cool areas.

TMS/BMS on 100% of the EVs is 99% win for those that will need it even one hour of one day of ownership and 1% of no effect for those that would never need it, 0% loss for 0% that non existent group that you think would lose.

Seriously you could gain more weight back on your leaf by switching from 17" rims and tires to 15" rims and tires than it would take to put the TMS system in (when designed that way from the start).

Sure it'll increase cost. But the payback to resale value and usability of the car is well worth it.

 

[WetEV]

If it is programmed not to come on and waste power when the temp is below the threshold for heat degradation it won't decrease battery life at all in cool areas.

To minimize heat conduction in hot place, the battery pack designed for TMS will need to be thermally insulated. That means in cool places the battery will warm up until the TMS cools it.

With a TMS, my summer battery temperature would be near the upper threshold temperature, say about 27C.

My battery this morning was 20.8C.

 

[gadyamit]

I suggest to read carefully about the Nissan NV200 electric car

http://insideevs.com/heres-nissan-employs-active-air-cooling-e-nv200-battery-pack/
https://transportevolved.com/2014/06/12/nissan-e-nv200-show-change-policy-battery-heating-cooling/

"LEAF owners in ultra-hot climates like Arizona however, a lack of battery cooling in the LEAF has lead to some pretty shocking premature ageing, rapidly decreasing battery pack capacity"

But this is not all
we can’t help but think Nissan is about to make a u-turn on its battery cooling policy

So as much as I understand the conclusion is obvious and now days TMS is a must

 

[dhanson865]

If it is programmed not to come on and waste power when the temp is below the threshold for heat degradation it won't decrease battery life at all in cool areas.

To minimize heat conduction in hot place, the battery pack designed for TMS will need to be thermally insulated.

The leaf pack is already thermally insulated. I don't think you are correct about the needs and effects of a TMS.

 

[dgpcolorado]

If it is programmed not to come on and waste power when the temp is below the threshold for heat degradation it won't decrease battery life at all in cool areas.

A TMS might also increase battery capacity in very cold weather by heating it, in particular if it could be done while still plugged-in. It would also help cold weather regen, something that is important where I live.


I realize that the PNW folks have been reveling in their greatly reduced battery degradation compared to the majority of the country, which is warmer. But it isn't just climate: I live in a cool climate — cooler than many parts of the PNW — but I had significant battery degradation. Why? Because I drive steep hills all the time and the high power levels required to do that caused substantial battery heating! After two years my range was so reduced that if it were not for a newly opened public L2 charge station I wouldn't have been able to make my routine 70 mile grocery shopping trips.

Perhaps someday battery chemistry will be sufficiently heat resistant to have minimal degradation without TMS. But we aren't there yet. One advantage of the coming larger batteries in the LEAF 2, and other EVs, is that the extra energy cost of running the TMS becomes almost irrelevant because range is not limiting. I charge my Model S60 to 50% or 60% and can easily make my routine local trips. I only charge to 90% when I want to make a long trip (something I did a lot when I first got the car and did 8000 miles in just over three months, including a trip to Portland and Seattle).

You can make the valid argument that the TMS wastes energy but I drive on solar power and pay nothing for electricity so I really don't care. I even run the AC at times when it is hot, something that I almost never did in the LEAF. I still drive fairly efficiently (once a hypermiler, always a hypermiler?) although usually not below the speed limit as with the LEAF. But I think that those who are driving range-limited cars now might be very surprised how liberating it is to have a car that has more than enough range to handle all local driving without thinking about it. The idea that TMS will decrease range slightly becomes completely irrelevant.

My 2¢.

 

[ydnas7]

.... All I'm saying is that I doubt Nissan (or any other OEM) is going to give us that choice.

The choice is the choice of the OEM.
GM for TMS, or Nissan for more range (aero)

similar budget, similar scope, simple choice range or TMS take your pick. or pay $10k more and get both in a TESLA 3.

LEAF 2 capacity warranty will match or exceed the warranty of LEAF 30kWh. 4 bars - 8 years - 100,000 miles

 

[gadyamit]

Other comments already covered the issue of cold climate i.e. we can't build cars that can only work in cold weather...
I assume that Japan as a cold climate country was the wrong place to test battery durability solution when Leaf was on the design board.

But for right now If Nissan came to that conclusion (i.e. TMS is needed) we should talk about other issues...

The next generation on-board charger....
For Leaf 2 a new on-board charger should have a automatic charging mode that limit full charge to about 85 %,
Only when you must have the full charge you can switch to a full charge mode. I assume that for less then 10% of our trips we need the full charge. So making the default mode to about 85% charge will increase longevity significantly. It should be simple feature.

 

[WetEV]

The leaf pack is already thermally insulated. I don't think you are correct about the needs and effects of a TMS.

Consider that heat is dissipated in the Leaf battery pack.

If more thermal insulation was added, the temperature of the pack would be higher. Would you suggest adding more? Or removing some? How about removing it all?

Or you might look at some of pictures and notice what isn't there.