Leaf range extension, just thinking

[DaveinOlyWA]

This sounds to me like what the original Prius plug in conversions did. I think they used contactors to parallel the additional battery pack to the Prius OEM battery. Or maybe they disconnected the OEM battery with one set of contactors and connected the conversion pack in its place with another set. Not sure, but it was something like that. I followed that stuff for a while, until I became convinced that pure electric was better.

yes and no.

1) the Prius battery pack and a lot of the charge monitoring and control systems were relatively easy to access. it was basically in the trunk. so it was easy to expand that since the battery sat at the bottom of the empty trunk area.

2) that additional battery pack brought the weight of the Prius up to the current weight of the Leaf. granted, not as balanced, etc. but definitely not several hundreds pounds heavier than the current Leaf.

3) the Prius pack is an add on itself. the Leaf is 100% EV so i believe integration would be tighter and therefore "shoehorning" something in there will not be as easy as it seems.

also the Prius was a bit "front heavy" to begin with, so adding a bit of weight in the back was ok. the Leaf is not which is why the placement of the current pack was probably VERY critical to the design of the Leaf.

i just dont see the gain of an additional 50 miles of range when its gonna cost that much money. is it really worth invalidating a warranty on an unproven car?

there is a million what ifs that are very possible here. this is a new product. the battery technology is on the move and the key thing here is that batteries too dead to run in a car still have a lot of value to them. this makes for a pretty powerful bargaining chip.

who is to say that Nissan will not offer a battery pack that is 25% more capacity at the SAME size and weight in a few years?

as far as the cost? well i would not buy a Tesla either, but many can and will.

 

[JRP3]

my wife and I are both 6'3" and with our two kids/car seats we can just fit in the car comfortably. Any smaller/shorter and we would not have been able to make it work.

Certainly lower vehicles than the LEAF can fit people your size, so lower seats with more rake could have done the job.

 

[mckemie]

my wife and I are both 6'3" and with our two kids/car seats we can just fit in the car comfortably. Any smaller/shorter and we would not have been able to make it work.

Certainly lower vehicles than the LEAF can fit people your size, so lower seats with more rake could have done the job.

I used to be ~6'4", now, probably ~6'3". I have at least 2" excess head room in the Leaf. Leg room is close to marginal. I would rather have a lower car with seats that jack up and down. And seats that move a bit farther back.

 

[mckemie]

With about 400 miles on our Leaf, it tells me our average speed is 36mph. With that low an average speed, the "charge while driving scheme" could yield additional range of 40+ miles. Sizing a secondary pack to "charge while driving" only would mean getting the weight down to 200-300 pounds.

What average speeds are other Leafs reporting?

I'm surprised at our average speed; I would have guessed around 45mph. Aside from stop and go city driving (a small fraction of our total), we drive about half the time at 40-45 on rural local roads and about half at 50-60 on larger highways. Generally, as slow as traffic will allow.

 

[DaveinOlyWA]

Then calculate the loss of range for the additional weight and the return simply has minimal value not to mention. The loss of storage

 

[JRP3]

For steady state driving that amount of weight would have little impact. For stop and go about the same impact as a heavy passenger. In other words, you'd still get a lot more usable range.

 

[palmermd]

my wife and I are both 6'3" and with our two kids/car seats we can just fit in the car comfortably. Any smaller/shorter and we would not have been able to make it work.

Certainly lower vehicles than the LEAF can fit people your size, so lower seats with more rake could have done the job.

I used to be ~6'4", now, probably ~6'3". I have at least 2" excess head room in the Leaf. Leg room is close to marginal. I would rather have a lower car with seats that jack up and down. And seats that move a bit farther back.

It makes a difference if your height comes from you legs or torso.

 

[DaveinOlyWA]

For steady state driving that amount of weight would have little impact. For stop and go about the same impact as a heavy passenger. In other words, you'd still get a lot more usable range.

Ok I can play "post useless info" game.

So how do you drive 400 miles in a Leaf without stopping?


When did weight stop being a factor?

What u * might* gain is 10%the increase in range which is 8-10the miles on a charge.

What r u willing to pay for that? There are a few people on the edge that might pay a few thousand for that. Problem.... u might not find it an easy job to do it for less than $5,000.

Well u can count me out.

 

[mckemie]

Then calculate the loss of range for the additional weight and the return simply has minimal value not to mention. The loss of storage

So what load related range reductions have you noticed on your Leaf? Or any other car, for that matter.

 

[DaveinOlyWA]

Then calculate the loss of range for the additional weight and the return simply has minimal value not to mention. The loss of storage

So what load related range reductions have you noticed on your Leaf? Or any other car, for that matter.

Driving is a huge factor. In town driving I could see around u. 2-.4 mpk with an additional weight of 300 lbs

* sorry. Son posted that* on freeway don't get consistent. Enough numbers. To tell

 

[JRP3]

Ok I can play "post useless info" game.

So how do you drive 400 miles in a Leaf without stopping?

You don't, who is looking for 400 miles in a LEAF without stopping?

When did weight stop being a factor?

It never has been for steady state driving. Heavier more aerodynamic vehicles can get better efficiency than lighter less aerodynamic vehicles in long distance steady state driving.

What u * might* gain is 10%the increase in range which is 8-10the miles on a charge.

300lbs of battery should be at least 12kwh which is half the existing LEAF pack, so about 40 miles of range.

What r u willing to pay for that? There are a few people on the edge that might pay a few thousand for that. Problem.... u might not find it an easy job to do it for less than $5,000.

Well u can count me out.

Me too, wasn't talking about the practicality, just the possibility.

 

[DaveinOlyWA]

Oh no no no.

U need to go back and reread this post.

Even if you had 12 kilowatts to put in there you couldn't do it lsu had some way of integrating that power into the pack which we have already figured that would probably be difficult to do.

So the other proposal that was suggested was to put the power into the charging port we had limited amount of christ I can be applied.

The posters said based on the amount of time it took to drive 400 miles he could've recharged 40 miles which basically means he going recharge very little on a normal range of driving

 

[mckemie]

The posters said based on the amount of time it took to drive 400 miles he could've recharged 40 miles which basically means he going recharge very little on a normal range of driving

What I INTENDED to say, and I think I did, is that I have 400 miles on my Leaf and my average speed has been 36 mph. Based on that 36 mph average speed, the car could be "charged while driving" (if such a capability existed) for about 3 hours on every full charge. That would result in about 40 miles in additional range. Reviewing my post, I just don't see how you could so horribly misunderstand it.

Of course, average speeds of others will be different from 36mph. I asked for the experience of others. This average speed appears on my dash display.

 

[JRP3]

Oh no no no.

U need to go back and reread this post.

Even if you had 12 kilowatts to put in there you couldn't do it lsu had some way of integrating that power into the pack which we have already figured that would probably be difficult to do.

I think you might need to go back and reread the post. I already said that I think it would be better to go through the fast charge port or go directly to the pack, and that it wouldn't be that difficult.

 

[rmay635703]

This sounds to me like what the original Prius plug in conversions did. I think they used contactors to parallel the additional battery pack to the Prius OEM battery.

No they didn't you don't want to recharge anything when extending your range, you only want to release energy into the motor at the rate you are using it, charging is very inefficient on a good day so don't bother.

yes and no.

1) the Prius battery pack and a lot of the charge monitoring and control systems were relatively easy to access. it was basically in the trunk. so it was easy to expand that since the battery sat at the bottom of the empty trunk area.

??? Meaningless, the expansion pack should not affect the SOC much.

2) that additional battery pack brought the weight of the Prius up to the current weight of the Leaf. granted, not as balanced, etc. but definitely not several hundreds pounds heavier than the current Leaf.

3) the Prius pack is an add on itself. the Leaf is 100% EV so i believe integration would be tighter and therefore "shoehorning" something in there will not be as easy as it seems.

It depends on if the leaf actively measures the amount of current into and out of the battery and with that also dissallows you to exceed its pre-programmed settings. The prius doesn't much care if your battery keeps delivering current for days so long as it is within a certain voltage.

As the old addage says "one way to find out".

also the Prius was a bit "front heavy" to begin with, so adding a bit of weight in the back was ok. the Leaf is not which is why the placement of the current pack was probably VERY critical to the design of the Leaf.

Nah, a good driver shouldn't care how his car is balanced, just be aware of how it is balanced.

i just dont see the gain of an additional 50 miles of range when its gonna cost that much money. is it really worth invalidating a warranty on an unproven car?

I agree no sense blowing a warranty,

That said, a boattail would be 1/20th the price of an upgraded battery and deliver the same additional 35 miles without changing anything else on the car or needing to bypass the cars software.

there is a million what ifs that are very possible here. this is a new product. the battery technology is on the move and the key thing here is that batteries too dead to run in a car still have a lot of value to them. this makes for a pretty powerful bargaining chip.

who is to say that Nissan will not offer a battery pack that is 25% more capacity at the SAME size and weight in a few years?

as far as the cost? well i would not buy a Tesla either, but many can and will.

I am waiting for someone to crash and junk their leaf, My Miles ZX40 leaf awaits.

 

[JRP3]

That said, a boattail would be 1/20th the price of an upgraded battery and deliver the same additional 35 miles without changing anything else on the car or needing to bypass the cars software.

Boat tail won't help your city and low speed range, and I'm not sure you'll get a 35% or so increase from it on the highway. Plus it usually looks like hell.

 

[rmay635703]

That said, a boattail would be 1/20th the price of an upgraded battery and deliver the same additional 35 miles without changing anything else on the car or needing to bypass the cars software.

Boat tail won't help your city and low speed range, and I'm not sure you'll get a 35% or so increase from it on the highway. Plus it usually looks like hell.

Look at ecomodder and at the Basjoos civic, highway it gets approx 92mpg (and we are talking 75mph highway) I am uncertain what a 20 year old civic should get for highway FE but I doubt its within 35% of 92mpg.

Also a boattail affects ALL speeds, especially when compared to a boxlike vehicle where aero becomes significant at about 15mph.

Even at 25mph about 25% of the drag on the leaf would be from aero, air up the tires to 50psi and that number becomes 50%, so yes although its not as effective on range at low speeds, but it still would have a minimum of about a 12% increase in range even at very low speeds.

And besides range issues usually aren't a city issue in a leaf unless you are gridlocked, I believe its the folks that want to drive 85mph that are most affected and complaining not the city folk.

The differences between a boattailed vehicle and a boxy one are so dramatic I think a good number of people would drive a boattail car and pay extra for it if they could see that one gets 50% better FE than another.

Not to mention all the trunk space.

 

[Herm]

Inflatable boat tail, deployed from a dash mounted button.

 

[JRP3]

I suppose someone could mock one up using duct tape and cardboard. Use a bike rack for support, the kind that attaches to a hatchback with straps and hooks. Compare power use with and without.

 

[DaveEV]

I've been waiting for someone to bring up a boat-tail. Has anyone shown up on cleanmpg or ecomodder with a LEAF to modify?

I estimate that with some improved aero you'd be able to travel 100 miles at 65-70 mph without too much trouble.

I still wonder what kind of highway range would be possible if the LEAF had the aero of the Prius with it's significantly lower drag and smaller frontal area... How long before someone drops the drivetrain into a Prius?