What if Nissan had engineered the LEAF BMS like the Volt?

[ydnas7]

Q: What if Nissan had engineered the LEAF BMS like the Volt?
A: It would cost like the Ford Focus Electric, but have the range of the Mitsubishi i

ie, very little sales



another question
What if the GM Volt was engineered like the LEAF (wide SOC allowable, no liquid cooling)
Ans, it would have 50% more range, would not have caught fire in the testing, and be cheaper.

ie much more competitive vs the LEAF

 

[garygid]

It might help to recall that a hybrid is required by California
to warranty the battery performance to remain within N%
(some small percentage) of new for a full 8 years, as I recall.

This includes the capacity, because the hybrid's overall
"low" smog rating is based on both the gas engine and the
expected electrical operation of the vehicle.

If the battery usefulness and use drops off, then the weighted
average pollution level increases, meaning that the car would
no longer be a low-pollution vehicle.

So, there was little choice in how to engineer the Volt.

The LEAF is a whole new, different, and wonderful ball game.

 

[Stanton]

Q: What if Nissan had engineered the LEAF BMS like the Volt?
A: It would cost like the Ford Focus Electric, but have the range of the Mitsubishi i
ie, very little sales

This is what I believe as well. We have to remember that there are (hard) decisions made with any truly new technology/product like the Leaf that require some future prognostication:
1) As battery capacity cost/performance increases, the "range games" played by TMS (and hidden capacity) will become moot
2) It's inevitable that Nissan will one day offer a (cost effective) battery capacity upgrade/refresh for the Leaf; they've already established the form/fit/function platform for it.

 

[dgpcolorado]

...2) It's inevitable that Nissan will one day offer a (cost effective) battery capacity upgrade/refresh for the Leaf; they've already established the form/fit/function platform for it.

If you are referring to better batteries in new LEAF models then I would agree that is "inevitable".

If you are referring to better replacement batteries in the current model LEAFs then I am skeptical. Much as I would like to see a significantly upgraded replacement battery pack, it strikes me as unlikely. Nissan is in the business of selling new cars, not upgrading old ones. Some sort of third party upgrades might take over for the older cars.

However, I'd sure like to be wrong about this.

 

[DaveinOlyWA]

I considered 50 miles of real EV range to be the minimal acceptable level for usage on the LEAF but did so assuming (or hoping) for a convenient public charging system down the road that would allow me to boost that 50 miles to whatever I needed. despite the slow start, i think that will happen.

this thing about making EVs like gas cars is simply stupid. there are trade offs in every aspect of life and we traded the World for the convenience of gas and I personally think that was a mistake, a big one. Gas powered vehicles have their place here and that place was vital to our economic expansion but the role has changed and needs to get MUCH smaller. EVs can take up a lot of that role but its not the same roll, its a complimentary one that more reflects changing transportation needs.

I say for all who think that EVs wont work for them. fine, buy what you think will work. I am guessing in 3-5 years (or however long it takes before you bite the depreciation bullet and convert) you will be back in the market again.

The Volt is not an EV. call it a "gateway" car if you like since it does allow you to get a better handle on what your driving needs are and what you are willing to do to drive electric.

I know a guy who thought about getting a LEAF but got the Volt instead due to concerns about the EV range limitation. His RT commute is about 35 miles. He works for the State, parks in State parking lot with charging and buses it to his office about 4-5 blocks away and does that every day just to avoid burning gas and has done very well so far. he also has a mini van which carries the family (3 kids, wife and 2 dogs) so its a crowd.

i asked him (a few times) how many times he drives over 40 miles in the mini van just to illustrate how much better the LEAF would have worked for him (keep in mind, the Volt does not have the seating capacity especially with one car seat and one booster) and still waiting on a response to that question.

i strongly suspect he rarely travels that far and is regretting his Volt decision (it was $40 a month higher payments i think...maybe $60...its been a while now)

My sister just took home a 2012 Fusion Hybrid with 2000 miles on Thurs. traded in a 20 mpg SUV (2011 Ford Edge) she is out of pocket $3000 on the exchange with her payments dropping from $470 to $310.

BUT (and this is a big BUT) if she did not work for Ford, she would have been out of pocket over $10,000 with payments nearly the same. They paid her KBB for her car (something car dealers NEVER do) and sold her the Fusion at cost plus $500 (which is basically break even for the dealer)

when she was in the market for a car, we tried to push her to a Prius or Fusion hybrid but she also had misconceived notions of her needs and that is why she go that monstrosity (which is actually a bit undersized compared to most people's perceptions of need :shock: )

but in my short stint as a car salesman I talked with people every day who had the same mis-perceptions. After driving a hybrid 8+ years, EVs for 5+ years, I pretty much can tell you how far it is between any two points within 50 miles of here and it was always people greatly overestimating their needs.

prime examples i hear "oh my round trip commute is 40 miles but with errands, it turns out to be more like 60 miles"

and i would say to myself "oh ya, after a long day at work, you are going to a grocery store that is 10 miles out of your way??"

but anyway, word of mouth is accelerating but i think it will take another 12-18 months to really kick in. The sightings of new EVs has really taken a noticeable bump up in the last week or so. (easy to spot when 3 still have temp plates!)

as far as TaylorSF; he probably "was" happy at 50,000 miles and Reg, i believe u when u said he said he was happy because he probably was but he is now at like 70,000? or something? and has to QC at least once a day to make it home (sometimes if the weather is good he can get to work without stopping)

but come Summer, he will have it made again. so, the LEAF has proven to be a decent option here relatively long term. My LEAF has just under 31,000 miles and probably has a 5% range loss (although my GID meter is currently averaging 98.5%) so it has also done very well.

 

[Volusiano]

Q: What if Nissan had engineered the LEAF BMS like the Volt?
A: It would cost like the Ford Focus Electric, but have the range of the Mitsubishi i
ie, very little sales

This is what I believe as well. We have to remember that there are (hard) decisions made with any truly new technology/product like the Leaf that require some future prognostication:
1) As battery capacity cost/performance increases, the "range games" played by TMS (and hidden capacity) will become moot
2) It's inevitable that Nissan will one day offer a (cost effective) battery capacity upgrade/refresh for the Leaf; they've already established the form/fit/function platform for it.

The original question is about BMS (Battery Management System). But gauging on these responses, maybe you guys are confusing it with TMS (Temperature Management System)? Yes, TMS would drive the cost up (like the FFE's cost), but BMS (battery management) should not be any more or less costly to produce between the Volt or LEAF. We're just talking about the software (algorithm) aspect of the BMS here, right?

 

[Stanton]

The original question is about BMS (Battery Management System). But gauging on these responses, maybe you guys are confusing it with TMS (Temperature Management System)? Yes, TMS would drive the cost up (like the FFE's cost), but BMS (battery management) should not be any more or less costly to produce between the Volt or LEAF. We're just talking about the software (algorithm) aspect of the BMS here, right?

Actually, I'm talking about TMS, which (as you say) would drive up the cost of any BEV; we all assume that no (competent) car manufacturer would produce a BEV without a BMS. My other point was that if/when battery pack capacities become large enough that we're not trying to squeeze every last mile out of it (like a Tesla), the TMS decision will become moot; you also won't have any unexpected/unknown consequences of a TMS "running down the pack" (also like a Tesla).

 

[Stanton]

...2) It's inevitable that Nissan will one day offer a (cost effective) battery capacity upgrade/refresh for the Leaf; they've already established the form/fit/function platform for it.

If you are referring to better batteries in new LEAF models then I would agree that is "inevitable".

If you are referring to better replacement batteries in the current model LEAFs then I am skeptical. Much as I would like to see a significantly upgraded replacement battery pack, it strikes me as unlikely. Nissan is in the business of selling new cars, not upgrading old ones. Some sort of third party upgrades might take over for the older cars.

However, I'd sure like to be wrong about this.

I was referring to a better replacement battery pack--and yes, I hope you're wrong too

 

[ydnas7]

It might help to recall that a hybrid is required by California
to warranty the battery performance to remain within N%
(some small percentage) of new for a full 8 years, as I recall.

true, but if GM had offered an HEV VOLT that just happened to have a plug and 16kWh of battery with wide SOC range, that vehicle would probably have greater new car demand than the official Volt.

same goes for thermal system, but i don't think LG allows those particular cells to sold without an active TMS.

 

[scottf200]

It might help to recall that a hybrid is required by California to warranty the battery performance to remain within N% (some small percentage) of new for a full 8 years, as I recall.

true, but if GM had offered an HEV VOLT that just happened to have a plug and 16kWh of battery with wide SOC range, that vehicle would probably have greater new car demand than the official Volt.

Lot of PHEVs have showed up from other manufacturers since the Volt came out. GM certainly pushed them farther/faster than homegrown PHEVs did. Of course none of the new PHEVs use electricity for pulpulsion like the Volt does (even under hard accel. or at any speed until the battery SOC is down to ~22). Volt sales seem to be OK (and outsold the LEAF worldwide last year -- see worldwide sales thread). If the LEAF is a success then so is the Volt. I think the "made up" competition worked in both their favors. I say made up because they are pretty different vehicles. I think the way the Volt works makes their owners consider a BEV much more/faster than the way the recent PHEV work for their owners. Much easier to go on electricity "only" in the Volt get "addidicted" in a sense.

 

[mkjayakumar]

I had thought of the same thought experiment as RegGuheert.

What if Leaf had an extra 5 kWh capacity and always offered 21 kWh usable capacity, year after year. In that case I would have bought, instead of leasing. No one would have complained atleast for another two years. Of course the challenge is to keep the costs down.

 

[planet4ever]

Actually, I'm talking about TMS, which (as you say) would drive up the cost of any BEV

Which means you are off-topic here. The whole point of this thread is to consider a BMS that initially reserves extra capacity, and doles it out as the battery ages to provide constant vehicle range. I don't know enough about the Volt to know whether it does that or not, but we certainly know that the LEAF doesn't.

I think Reg has raised a very good point here. Nissan would undoubtedly be squirming less had they followed this approach. How much, if any, their sales would have suffered is an open point. What if they had told us up front that the estimated range is 60 miles, and they provided a battery warranty covering replacement if that range (measured on an annualized basis) reduced within three years or 36K miles?

Ray

 

[Volusiano]

Actually, I'm talking about TMS, which (as you say) would drive up the cost of any BEV

Which means you are off-topic here. The whole point of this thread is to consider a BMS that initially reserves extra capacity, and doles it out as the battery ages to provide constant vehicle range. I don't know enough about the Volt to know whether it does that or not, but we certainly know that the LEAF doesn't.

I've started following the GM-Volt forum for the last 3 months and I get the impression that nobody over there knows whether GM made plan to eat into the extra capacity over the long run or not to preserve the advertised range of about 40 miles.

However, I can tell you that nobody seems to have any capacity loss anxiety over there. And they're also confident that the Volt has capacity warranty of 70% capacity over the course 8 years/100K miles (unlike Nissan's claim to be the only auto mfg with a battery capacity warranty), which also trumps Nissan's warranty of 9 bars over 5 years/60K miles.

I think Reg has raised a very good point here. Nissan would undoubtedly be squirming less had they followed this approach. How much, if any, their sales would have suffered is an open point. What if they had told us up front that the estimated range is 60 miles, and they provided a battery warranty covering replacement if that range (measured on an annualized basis) reduced within three years or 36K miles?

If they had told people up front that their estimated range is only 60 miles (instead of the advertised 100), then they would have lost a lot of sales to the Volt, regardless of whether they have a battery capacity warranty up front or not. Nissan had no choice but to make 21 kwh of their 24 khw battery available in order to be able to claim as much as 100 mile range as they could. So their strategy is so different than the Volt strategy that they wouldn't really have an option to model their BMS strategy the way GM did the BMS for the Volt anyway. Assuming that the Volt model their BMS to eat into the margin to preserve the range. That's a big assumption that's never been verified by anyone.

Also, remember that GM's capacity warranty is 70% after 8 years/100K miles. If they had modelled their BMS to eat into the buffer to maintain their range, why would they still account for up to 70% capacity loss after 8 years/100K?

 

[RegGuheert]

Also, remember that GM's capacity warranty is 70% after 8 years/100K miles. If they had modelled their BMS to eat into the buffer to maintain their range, why would they still account for up to 70% capacity loss after 8 years/100K?

Perhaps that is what the law requires? But note that such a BMS strategy does not mean usable capacity will not drop. It means capacity will not drop until the BMS hits some other limits on upper and lower SOC range. At that point, there is no more possibility to hide degradation and both the available capacity and driving range will begin to drop.

Regardless of how the Volt BMS works, their capacity warranty is to have 70% of 65% of the battery at the end of the warranty period, which is 45.5% of the total new battery capacity. In terms of the LEAF, which gives access to 92% of the battery when new, that warranty would be like Nissan offering a warranty to not go below 50% of original battery capacity. In other words, Nissan would warrant only after the seventh capacity bar disappeared and only six were still showing (actually slightly lower than that).

 

[DaveinOlyWA]

this has become an interesting if not wandering discussion but in a nutshell, I would have been very pissed off if Nissan had required us to haul around dead weight which is the reason I did not purchase the Volt because that is what the Volt is doing.

To be honest with you, if the Volt had a 60 mile EV range, i probably would have bought it but then again, it would also have to have QC

 

[scottf200]

I've started following the GM-Volt forum for the last 3 months and I get the impression that nobody over there knows whether GM made plan to eat into the extra capacity over the long run or not to preserve the advertised range of about 40 miles.

Yes, it is sort of a myth that likes to gets repeated here on MNL. There was a comment made in an interview to that affect as I recall but nothing remotely official. After 21K EV miles in my 2011 it has not appeared to lose any range. 30 winter, 45 summer (2011/12-EPA 35, 2013-EPA 38).

The ~22% to ~87% SOC has been shown in DASHDAQs and it will be interesting to see what the ELR shows. Multiple GM comments indicate they are using more of the battery. That bodes well for thier confidence.

 

[TomT]

Yes, it would appear that in addition to the battery composition change for the 2013 capacity and range increase, GM is also now confident about allowing a little bit more of it to be used...

The ~22% to ~87% SOC has been shown in DASHDAQs and it will be interesting to see what the ELR shows. Multiple GM comments indicate they are using more of the battery. That bodes well for their confidence.

 

[Volusiano]

this has become an interesting if not wandering discussion but in a nutshell, I would have been very pissed off if Nissan had required us to haul around dead weight which is the reason I did not purchase the Volt because that is what the Volt is doing.

It's not dead weight if it's there to serve a useful purpose as a range extender.

Let's take this scenario, that 99.99% of your driving need is 40 miles or less.

1. You'll never need to use the ICE on the Volt so you consider it dead weight. I don't know what the weight of the Volt's 1.4L 4L engine is (seems hard to find anywhere), but I'd venture to say that it's around 400 lbs.
2. If you had the LEAF, and assuming that the LEAF has 75 miles range, then ((75-40)/75)% of your LEAF's battery can also be considered dead weight as well because it'd never get used if you almost always drive 40 miles range top. The LEAF's battery total weight is 660 lbs. So (35/75)% of 660 lbs is 308 lbs of "dead weight".

So the point is that if you only drive 40 miles or less most of the times between recharges (so you can consider the Volt's ICE dead weight), then the LEAF has 308 lbs of dead weight just as well.

To be honest with you, if the Volt had a 60 mile EV range, i probably would have bought it

To my surprise, I routinely get 50+ mile range on the Volt driving at 45 mph with no AC/heat. Even if I do most freeway driving, I can still get 40+ mile range easily (with no AC/heat). And so far after 2 years of driving, nobody is complaining about range loss on their Volt. So its range is closer to your 60 miles criteria than you think.

but then again, it would also have to have QC

Yes, QC is nice but obviously QC is not needed for the Volt so that's why they don't have it.

OK, it's still nice to have if you can fill up quickly while out and about for free. But when QC is no longer free, the economic of charging using QC may not be any more advantageous than using gas. For example, L2 charging right now at $1/hr (discounted Blink member rate) would require 4 hours to fill up the Volt at the cost of $4 to go 40 miles. Gas currently at under $4/gallon that can get you 40 miles range, so economically using gas versus charging at L2 in public is a wash. So there's no economic incentive to use L2 charging in public at that rate.

If QC fee is going to cost $4 to charge up 11 kwh of charge, QC charging (on available in public) doesn't make economic sense for the Volt either.

 

[DaveinOlyWA]

this has become an interesting if not wandering discussion but in a nutshell, I would have been very pissed off if Nissan had required us to haul around dead weight which is the reason I did not purchase the Volt because that is what the Volt is doing.

It's not dead weight if it's there to serve a useful purpose as a range extender.

Let's take this scenario, that 99.99% of your driving need is 40 miles or less.

1. You'll never need to use the ICE on the Volt so you consider it dead weight. I don't know what the weight of the Volt's 1.4L 4L engine is (seems hard to find anywhere), but I'd venture to say that it's around 400 lbs.
2. If you had the LEAF, and assuming that the LEAF has 75 miles range, then ((75-40)/75)% of your LEAF's battery can also be considered dead weight as well because it'd never get used if you almost always drive 40 miles range top. The LEAF's battery total weight is 660 lbs. So (35/75)% of 660 lbs is 308 lbs of "dead weight".

So the point is that if you only drive 40 miles or less most of the times between recharges (so you can consider the Volt's ICE dead weight), then the LEAF has 308 lbs of dead weight just as well.

To be honest with you, if the Volt had a 60 mile EV range, i probably would have bought it

To my surprise, I routinely get 50+ mile range on the Volt driving at 45 mph with no AC/heat. Even if I do most freeway driving, I can still get 40+ mile range easily (with no AC/heat). And so far after 2 years of driving, nobody is complaining about range loss on their Volt. So its range is closer to your 60 miles criteria than you think.

but then again, it would also have to have QC

Yes, QC is nice but when QC is no longer free, the economic of charging using QC may not be any more advantageous than using gas. For example, L2 charging right now at $1/hr (discounted Blink member rate) would require 4 hours to fill up the Volt at the cost of $4 to go 40 miles. Gas currently at under $4/gallon that can get you 40 miles range, so economically using gas versus charging at L2 in public is a wash. So there's no economic incentive to use L2 charging in public at that rate.

If QC fee is going to cost $4 to charge up 11 kwh of charge, QC charging (on available in public) doesn't make economic sense for the Volt either.

"free" is not my concern since it would have to be pretty expensive to be more money than gas.

the engine may weigh 400 lbs but the total gasoline drive system is probably closer to 1000 lbs.

as a conservative driver, i always felt that i could easily get 45-50 miles in the Volt much like I can get near 90 in the LEAF...in Summer. but we have MUCH more Winter than Summer so your ability to get what you get does not apply to me.

dead weight= battery you can NEVER access which means its a moving target and for me, it would be that way for years since my TMS-less battery seems to be doing quite well so far.

but you imply that my dead weight is the battery that takes me 41 + plus miles and there was a time when I averaged less than that daily but those days are long gone. moves, job changes, etc. has never really put me that category.

when SO changed from commute of 64 miles to 9 miles, my commute did just the opposite (actually my commute changed last Summer) so what we gained in reduced commuting we had already added back.

But SO was never comfortable driving LEAF in Winter despite doing so several times without being stranded (this is same person who ran out of gas in the 53 MPG Prius THREE TIMES ) but that never meant that the LEAF was lightly used.

Only 2 months has the gasser exceeded the mileage of the LEAF and both were due to long multiple day trips. this month which is first full month that Fife DCFC (a vital link to being able to extend the usability of the LEAF in this area from all directions) has been online (and very reliable so far...Blink, you finally did something right!) and i will log about 2000 miles on the LEAF with the gasser logging roughly 326.6 miles.

this could not have been done in a Volt

 

[mkjayakumar]

I don't agree with 'dead weight' and the negative connotation with that. You can make the same argument with your back seat, which is perhaps used once or twice a week and i am dragging it along every time.