How much battery capacity is ideal for your LEAF?

[gbarry42]

The deal maker here is to be able to do a 70-mile drive regularly. At freeway speeds. This was our original expectation for this "100 mile" car. I'd say, pretty much what one gets from a RAV4 EV. Thus the 36 kWh guess.

Any more than that, and I'm just being greedy. And hauling around more than I need. If I didn't mind hauling around extra weight that I only got to use occasionally, a Volt would work nicely. Right now, it's a Prius that takes care of out-of-range trips, and trips farther than stated are rare.

Come to think of it, one 100-mile LEAF and one 50-mile LEAF would suit our two-car family. Only one of them needs to be able to go far away.

 

[DNAinaGoodWay]

Is this one of your LAB assignments?

I voted 48, but then 3 QCs popped up in a week and more to follow seems, so could easily live with 36, even after ten years in cold of winter.

Instead of an ICE loaners for long trips, being able to switch out loaner battery trailers at dealers nationwide would be cool. Like the pony express.

 

[GRA]

I haven't answered the poll, because I think it asks the wrong question. Although I'm well aware of the relationship between battery size and range, ultimately I don't care how big the battery is, what matters to me is dependable range with a given battery, at a given price and under given conditions. So, unless the assumption is that there will be zero improvements in specific energy/energy density or drivetrain efficiency for the next generation, any calculation of required battery size is likely to be invalid. I'd think the poll would be more useful asking for EPA range@price.

 

[RegGuheert]

I am also assuming that this new capacity battery would be a "hot battery" or better, not more of the current chemistry and configuration.

Yes, that is one of the assumptions provided in the OP.

Is this one of your LAB assignments?

Good question! No, it is not, but I intend to point Nissan to this thread anyway.

 

[DanCar]

I think the $2000/6kWh is rather optimistic, especially when one gets to the larger battery sizes that would require a bigger and much heavier vehicle...

What would be more realistic?

 

[DaveinOlyWA]

Definitely not a LAB thing here. (cant believe anyone here would think that :shock: )

I think you should

1) reduce the pack options to something that might happen so no more than say 4 (which is still a HUGE stretch but at least conceivable) and no bigger than say 48 kwh?

2) bill AT LEAST $500 per Kwh. its not feasible for me to go to 36 Kwh (my choice because add QC and I have a much larger range for the same price as the car I am driving now...)

3) also if this is the future, there should be a discount for the 24 kwh (remember the 8% rule!)

i would go 24,36, and 48 for

$25,000; $33,000; and $40,000 base

polls mean nothing if they are based on...well nothing

 

[KJD]

I think the $2000/6kWh is rather optimistic, especially when one gets to the larger battery sizes that would require a bigger and much heavier vehicle...

What would be more realistic?

Well since Nissan refuses to tell us a price we can only guess, so here is my wild guess.

$2000/6kwh works out to $333 per kwh.

If you look at the Tesla there is a $10,000 price difference between the 60kwh car and the 85kwh car. That works out to $400 per kwh.

I have read estimates anywhere from $250 to $500 per kwh, but most estimates I have seen were closer to 500 than 250, so I think Reg's number is a little bit low, but not off by that much.

I think $400/kwh is more realistic.

 

[garygid]

Going 80 miles one way, with lots of 24/7 quick recharging
would do for me. So, the battery size could still be modest
if the refueling network was substantially better.

However, in CA, it looks like a few Hydrogen fuel cells will get
about 10 stations ($2 million each) a yer for the next ten years.
If that money went to 100 QC type EV charging stations each
year, it seems to me that the 30-year benefit would be much
greater. Hydrogen infrastructure is expensive and vehicles scarce.

Without a 24/7 improved fueling network for EVs, they will
continue to struggle, even with better, larger batteries.

Charging infrastructure is still being derailed.
I wonder who would be doing that?

 

[johnrhansen]

How about a fuel cell powered range extender?

 

[DaveinOlyWA]

How about a fuel cell powered range extender?

would have to be a big one for that 800 mile detour to the filling station!

 

[TomT]

The drive line is already highly efficient and there is little additional to be wrung out of it... Thus, that is not really not much of a consideration in future range considerations...

So, unless the assumption is that there will be zero improvements in specific energy/energy density or drivetrain efficiency for the next generation, any calculation of required battery size is likely to be invalid.

 

[RegGuheert]

The drive line is already highly efficient and there is little additional to be wrung out of it... Thus, that is not really not much of a consideration in future range considerations...

Precisely.

On top of that, I think talking to Nissan in terms of available miles of range is ill-advised since they tend to use a super-low-speed Japanese driving standard which is incredibly optimistic in terms of miles driven per kWh.

The bottom line is LEAF owners know what we can do with the 24 kWh battery we have today. I'm asking them to suggest what they think would best suit them in a future LEAF.

Regarding the choice of $333/kWh for the incremental battery price, I went back and forth on what to use here. I decided to err on the low side since I expect we will cross that point at some (unknown) time in the future. Of course Dave is right: that would necessarily drop the COST for the base model, as well. But I will point out that lowering the manufacturing cost does NOT necessarily equate to lowering the PRICE.

Like all hypothetical polls, this one certainly has its flaws. Still, I am finding the responses to be very interesting! I will ask that current LEAF owners please vote if you haven't already.

 

[DaveEV]

If you look at the Tesla there is a $10,000 price difference between the 60kwh car and the 85kwh car. That works out to $400 per kwh.

Tesla priced the 85 kWh car so that it gets higher margins than the 60 kWh car. The cells themselves are rumored to cost Tesla closer to $200 / kWh. Don't forget that $2,000 of that cost is Supercharger access, so it's really $8000 for 25 kWh, or $320/kWh.

Now Nissan's price for the cells is likely higher than Tesla's (Tesla is able to take advantage of 18650 manufacturing scale), but they are also probably operating on a lower profit margin than Tesla's 25% target margins, too.

The drive line is already highly efficient and there is little additional to be wrung out of it... Thus, that is not really not much of a consideration in future range considerations...

Yeah, not much left to be wrung out of the drive train, but any little bit helps.

On the other hand, the body could easily be made more aerodynamic and a larger battery will also allow for higher levels of regenerative braking which at least in city driving could offset any hit to efficiency due to extra weight.

 

[KJD]

If you look at the Tesla there is a $10,000 price difference between the 60kwh car and the 85kwh car. That works out to $400 per kwh.

Tesla priced the 85 kWh car so that it gets higher margins than the 60 kWh car. The cells themselves are rumored to cost Tesla closer to $200 / kWh. Don't forget that $2,000 of that cost is Supercharger access, so it's really $8000 for 25 kWh, or $320/kWh.

Good point, so maybe Reg's number is closer than I thought.

With this in mind the 2.0 LEAF should have a pack size in the range of 36 to 48kwh. At least for the SL model. This would give current owners a good reason to upgrade and Nissan can still under cut the price of a Tesla by a wide margin.

 

[DanCar]

... With this in mind the 2.0 LEAF should have a pack size in the range of 36 to 48kwh...

Hopefully the e-nv200 will have these options. Also the performance pack with 0-60 in 5 seconds. Lol

 

[Foible]

If I could rent replaceable battery packs or a charging trailer for longer trips I could get by with a battery half the size of the current one. It irks me that I've got 650 pounds of batteries slowly degrading in my driveway when I rarely use more than fifty percent of my range.

Now that I drive an electric car I can't think of the battery like a gas tank anymore, it is an active component of the car. I want a setup like we have for propane tanks. Bring in a dead battery back, pay a swap fee and drive out with a fully charged one. Let the battery company due cell maintenance and roll the price into my swap fees.

 

[TomT]

I voted for a 48Kwh battery... That would give me the capacity to do most of what I need to, while being cost effective, and would provide a cushion against future degradation. It would also reduce cycle degradation as I would need to charge less frequently and/or less deeply...

 

[DaveinOlyWA]

the thought of getting an overly large capacity and then cycling the middle is a grand one but I dont think the chemistry has advanced enough to make that feasible yet.

Might be interesting to cost out a NiMH pack for something like that. They are cheaper right? but guessing more toxic so not sure that is the way to go.

Ya, it would be convenient to have the extra capacity when you need it but I think its still more cost effective to have a real public charging infrastructure and range extenders to use in areas where the population density is low enough where public charging does not make sense.

as far as support?? lets face it. if we had to pay the real cost of what everything costs we simply would not have it. that is what taxes are for. to pay for the things we wouldnt pay for on a per use basis.

is it fair? well, lets face it. no matter what the answer is, that was "resolved" a long time ago.

Either way; the only real no brainer in this equation is MORE OPTIONS.

multiple battery sizes, leases, purchases, extender rentals, public charging, etc. IT IS ALL NEEDED

 

[Levenkay]

The existing LEAF battery size is a pretty good compromise amongst the various factors (range, cost, weight), at least in as-new condition. Although the concept of interchangeable pack sizes is appealing, I think the thing I'd agitate for is for Nissan to address the problem of cooling the existing pack when it's under heavy (multi-QC) use. I think that would give the biggest improvement to the car's usefulness for the least cost & weight.

 

[GRA]

The drive line is already highly efficient and there is little additional to be wrung out of it... Thus, that is not really not much of a consideration in future range considerations...

Precisely.

I was thinking more in terms of making changes to the power controls etc. ala' Spark EV, that would boost the efficiency at highway speeds which is where the extra range is most needed. I agree that we'll likely see only small % improvements as far as drive train friction etc.

On top of that, I think talking to Nissan in terms of available miles of range is ill-advised since they tend to use a super-low-speed Japanese driving standard which is incredibly optimistic in terms of miles driven per kWh.

<snip>
Which is why I specified 'EPA range', so they couldn't play such games. If it were up to me I'd specify US06 range solely, minus a reserve and allowing for 20% degradation plus low temps and HVAC use, instead of a mix of LA4, HWFET, US06 etc. in ideal conditions, but I'd settle for the EPA mix.