Future Battery Replacement - A Better Battery?

[Zelenec]

The bigger problem will be putting an expensive battery into a 10 or 15 year old MIEV.

- I bought the car because it was cheap, not because it was the finest EV on the market.
- Its a cheap little basic economy car. The only reason it had such a high sticker price is because it has a $20,000 battery in it. Surely over 10 to 15 years the seats and interior appointments will show wear to the point that we'll be ready for something newer.
- Meanwhile battery tech, new models and designs, will most likely mean that in 10 to 15 years we can move on to an EV that's much better designed, with much better range and style.
- Of course, the industry could go the other way. With low gas prices --- In 10 to 15 years we could remember the years of 2011-2016 as the days when car makers dabbled in Electric cars. If that scenario were to play out then, yes, we'll be looking for ways to keep our antique EV's going by adding replacement batteries.

I couldn't agree more

 

[DogMan12]

I will after 5 yr zero interest be into my MiEV about $16,000. I am already disappointed but not shocked at the resale value. I suppose if I get 8 years and 80-90,000 miles for $16k, with zero value at the end, that is not terrible, but not what I hoped for, either.

IF the suspension and other major systems are functioning, and IF I can get a Batt for less than $400/kwh installed, I BELIEVE I will do it. But as you have said, what will the context be in 2020?

 

[jray3]

iWatson hit the mark- our "i"s may not economically justify a second life. However, part of our master plan for MR BEAN is that he'll turn ten (and be approaching 180 kilomiles) as my daughter gets her license, and by then the nest egg should have hatched a TESLA or equivalent. Nothing like a range-compromised little people pod for the girl to make her daily 5-mile run to high school and extracurricular activities within the immediate area, but not allow spur-of-the-moment joyrides to the big city! If MR BEAN survives the high school driver (and her little brother), he'll either be due for retirement or a loving restoration! My main concern is whether a replacement battery is needed before then. If the car's practical range falls to 40 miles much before the teen needs wheels, that would probably be my trigger for pack replacement. Economics could push that trigger down to 30 miles of 'autonomy', since we have fast-charging (and a pusher trailer), but even my enthusiasm for public charging adventures has its limits.

 

[iwatson]

Jray3,

My daughter turns 19 next month and although she likes the i-miev and will drive it, she wants to take my Volt away from me, or better yet, "daddy buy me a Camaro".

Good luck talking your daughter into a limited range, all-electric car. May sound good on paper (Trust me I have same thoughts as you "keeps um close to home", "she can't wander too far off", "It's all she needs for the little bit of driving she does", "No way I'm paying for gas for her to drive all over town", "maybe the boys won't be interested in the girl that drives the dorky car"), but your plans may not line up with hers.

i-miev owner's are the most practical, rational people on the planet....They would have to be to drive THAT car! Kids.....not so much!

After all, weren't you a kid once? What kind of car did you want?

 

[DogMan12]

After all, weren't you a kid once? What kind of car did you want?

A Corvair. Well, a '65 turbo Corsa 4 speed, but a Corvair. Favorite as a young adult was a '47 International KB-2 pickup. (Tip-open windshield!)

No heirs here to give the MiEV to, just my own retirement to match the greying of the battery. Thanks, jray, for the list of current pack builders!

 

[jray3]

Jray3,
After all, weren't you a kid once? What kind of car did you want?

Ha-ha. Got a Karmann Ghia, just like I'd asked about at 4 years old, and still have Ghias!
Automotive monogamy ain't for everyone, but it's perceived to be a positive character trait by discerning women!

 

[Benjamin Nead]

Hi all . . .

If all goes well, I will be the owner of a used ’12 ES in October. The current
lessee (friend and fellow member of the local EV club here in Tucson) is handing
it back to the dealer then following his 3 year rental commitment. I actually got
to borrow this very vehicle in the fall of 2013 for a couple of weeks and became
sold on owning an i-Miev then. The price is right for the purchase of a clean used
i-MiEVs these days (affordable to even poor ol’ me) and I know this one has been
well taken care of.

So, in anticipation of all this, I’ve been catching up with my reading here as of
late and came across this thread on replacement batteries. My guess is that I’m
not going to be a candidate for such a thing for many years to come, but the
technical aspects of what is possible along these lines in the future intrigues me.

First, present day wet blanket time . . .

I’m simply not seeing how thirty 18650 cylindrical cells can fit inside a box the
size of a LEV50 (171mm X 115mm X 44mm.) But I’m also assuming that the most
desirable thing would a physical drop-replacement for a LEV50 with the same 3.7V
and an increased amperage, so I’m starting with that criteria in mind (worrying later,
of course, on how the car’s computer might electronically hiccup with a battery
module output greater than 50Ah.)

Undaunted, I spent today moving appropriately-sized shapes around in Adobe
Illustrator to see what really is possible. The best I could come up that allowed for
logical cell placement, breathing space between the cells themselves and for everything
else you would want inside each of those 88 modules (BMS board, provisions for
robust mounting of the terminals on top, allowances for wall thickness of the box
itself, etc.) was sixteen 18650 cells.

The current Tesla cell is, I think, the Panasonic NCR18650B, with the proper
3.7V for series wiring (good news there) and rated at 3.4Ah (or 3400mAh) each . . .

https://www.fasttech.com/product/1141100-panasonic-ncr18650b-rechargeable-3400mah-3-7v

But sixteen of these in series would yield only 54.4Ah, which isn’t really enough
to make the venture worthwhile today. And, while I’m sure a more advantageous
pricing structure could occur when purchasing thousands in bulk instead of
a handful from a retailer like I’ve linked to, $3 per cell might always be wishful
thinking.

Now, for the potential future good news . . .

It’s been widely reported that the cell Telsa is destined to make in their upcoming
gigafactory is going to be physically larger: a 20700 (20mm diameter X 70mm
length) form factor . . .

http://gas2.org/2015/03/18/lighter-batteries-may-prove-tipping-point-electric-vehicles/

Assuming the chemistry is the same and allowing for a modest increase in
performance of the basic nickel/cobalt/aluminum oxide formula by production
time and in the years that immediately follow, it’s not unreasonable to assume
that this larger cell would be capable of an output between 4 to 5Ah. The physically
larger size of the cylinders is also good news in regards to fitting inside a LEV50-sized
box, as 20700s take up extra space in there over the 18650s quite nicely and it’s still
far from being cramped . . .

http://i1089.photobucket.com/albums/i358/BeninTucson/LEV50_W.jpg

So, sixteen cells in the right sized box could yield between 64 to 80Ah per module.
16 X 88 modules = 1408 cells. That’s between 5232Ah (@ 4Ah per cell) and 7040Ah
(@5Ah per cell) for the whole pack. Multiply by 3.7V and that’s (respectively)
between about a 19.36kWh and 26kWh pack (someone please check my math!)

Assuming buying in lowish volume wholesale quantities is possible (by the
crateload, as opposed to by the shipping container-full,) around $5600 ($4 ea.)
to $7000 ($5 ea.) for all those cells to make what could be a 26kWh pack looks
pretty good . . . especially if a drop-in prismatic replacement for the LEV50
isn’t being made a few years from now.

We’ll also be waiting for news regarding things like lithium sulfur and (my favorite)
solid electrolyte technology to get here while all of the above is happening.
But that’s another battery dream post for another time.

Thoughts? . . .

 

[JoeS]

Benjamin Nead, welcome back after an absence of 3-1/2 years.

Two quick points:

1. Good luck in trying to obtain a particular lease return. Others have tried and failed. The buyback amounts were ridiculously high, which people with existing leases refused to pay. The returned cars get swallowed up and spit out at (unknown) auctions, only to be picked up by (mostly) clueless dealers for ridiculously low prices. If you are able to arrange this purchase ahead of time, please do let us know how you did it.

2. Regarding battery replacement, I posted this on one of the other threads: Until a hack is developed for the i-MiEV's battery management system and the ability to integrate it with, or spoof, the existing digital interface, I think we have a problem.

There are two reasons for wanting to pursue this digital hack:

a. Future battery replacement (the subject of this topic) with different chemistry and/or form factors (the subject of your post)
b. Increase the capacity of our existing pack.

We still have about five years of warranty left on our 2012 vehicles. A lot can happen between now and then.

Some of us have postulated that an add-on pack *should* work with no digital mods needed if inserted in the *right* place. Thus, adding a self-contained second pack with its own BMS and charging system may be preferable instead of shoehorning different cells into the existing box.

I submit that the focus of our present endeavours should be to figure out how the battery signals work so we can safely integrate with them.

Keep in mind, anything we do should not only preserve the safety features built into the vehicle, but also implement safety features which are at least as good into any mods we put in.

 

[Don]

i-miev owner's are the most practical, rational people on the planet....They would have to be to drive THAT car! Kids.....not so much!

After all, weren't you a kid once? What kind of car did you want?

We were all kids once and I'm sure most of us did not get anything we wanted handed to us by our parents

I wanted a '57 Chevy and I got one . . . . at zero expense to my parents. The 'rule' was . . . . so long as you have the price of the car AND the first years insurance saved up, you can buy and drive anything you want

My daughter got our old VW Rabbit to drive her senior year in high school and our son 4 years later got an $800 Ford Escort - I'm sure neither of those were 'first choices' but if they had to live by the old 'rule' they both would have been walking for another year or two

In this day and age, *IF* I was buying the car, *AND* the insurance for it, *AND* the gas to move it, the car would be 95% what *I* chose and "Daddy buy me a Camaro" would fall on very deaf ears. My daughter wrecked the aforementioned VW Rabbit 3 different times (with ME making it roadworthy again the first two times) before we sent it to the junkyard and she began buying her own *choice* of vehicles

After all, weren't you a kid once? What kind of car did you want?

A Corvair. Well, a '65 turbo Corsa 4 speed, but a Corvair.

Ah, yes! That brings back memories. I had a '65 Corsa onvertible as my 3rd or 4th car, shortly after I joined the Air Force - I bought it as a basket case and put it together myself, down to the last nut and bearing in the engine. It was the fastest thing on 4 wheels down the North Bend AFS Oregon Radar Site road and the second fastest thing *UP* the road. I still had it later on here in Mississippi when I met my wife. We loved it! 30 years later, I bought a '66 Corsa convertible (better transmission than in the '65 model) and we restored that one and drove it in some antique car events. Both were the 4 X 1 bbl 140 HP models - Never cared much for the 180 HP turbo models . . . . the turbo lag in those cars was terrible, but once you got them up and going, they were rockets!

Don

 

[Phximiev]

Saw this optimistic report about triple the Yuasa battery in another iMiev forum post:

http://www.electric-vehiclenews.com/2014/11/next-generation-gs-yuasa-lithium-ion.html

 

[Benjamin Nead]

Thanks for your reply, Don

Yes, I actually joined here back in 2011 to quickly comment on the interior appointments
of the then-new North American i-MiEV. Hopefully, you’ll be hearing from me on a more
regular basis from this point forward. No way of really knowing way back then that this
would be the EV I would be focusing on now.

And, yes, fingers crossed regarding my upcoming i-MiEV purchase attempt. I’ve heard from
others regarding difficulties on this front. Never underestimate the intransigence and quirkiness
of auto dealers and realtors! The good news is that I’m now regularly seeing reasonably priced
used i-MiEVs pop up on the online listings, as so many of the leased EVs from the 2011-12
time period are now heading back to the dealer’s lots. So, if not my friends vehicle, I’ll be on
the hunt for another used i-MiEV. We’ll see what plays out this fall.

In regards to batteries: I was basically thinking out loud here in my post. What got me started
was realizing that it would be simply impossible to put thirty 18650s inside a box the size of
a LEV50 battery and then wondering what would really work along those lines. I’m not about
to embark on a tear-down in a vehicle with plenty of warranty time left on a well-functioning
pack and with cell capacity present just to say I did it. That sort of craziness is something I hopefully
got out of my system long ago.

But what does happen in, say, 2022, when any number of i-MiEV batteries begin to falter under
normal wear and tear, with warranties long expired and replacement LEV50s possibly being long
unavailable? As you have said, much can happen between now and then. Pondering the possibilities
now of what could be possible then might not be unwise.

And, to clarify, I’m more concerned about what will happen with dead or dying packs to preserve
the life of an otherwise perfectly good vehicle, as opposed to wiring up an add-on range extender
into a well functioning i-MiEV in the near term. Part of the appeal of the i-MiEV for me is the
generous cargo space when both rear seats are folded down. The idea of having a big black box
constantly present back there with cells doing nothing more than giving me an extra 15 or 20
miles for a rare long trip sort of ruins that.

I am familiar, though, with the concept of integrating disparate cell types and a supplementary
“spoof” circuit into the existing system. I’ve seen this done successfully with a Prius (Plug-In Supply’s
conversion kit,) where a pack of Headway LiFoPO4s interact seamlessly with the Toyota’s stock NiMH
pack and turns the car into a plug-in hybrid.

Likewise, I’m also witnessing an ongoing restoration of a rather rare 1999 Ford Ranger EV
(club member project,) where the essentially fried - and very large - NiMH pack got dropped,
the shell pried open and the old cells finally getting discarded (the original plan was to individually
cycle the vintage NiMH cells, but that didn’t work out.) New Calb 100Ah LiFePO4 units now live in
the vintage shell and are in the process of being wired together as we speak. This NiMH-to-LiFePO4
conversion is requiring a new BMS to supplement the old stock one and a custom circuit box being
wired between them in “spoof” fashion, In addition to all of this inside the pack, a new charger
replacing the old one now resides underneath the hood.

It’s rather crazy stuff to contemplate today, since there are not that many 17 year old EVs out there
right now in need of an upgraded battery pack. But this is going to change over the next few years
with stock EVs beginning to proliferate now.

 

[Benjamin Nead]

Saw this optimistic report about triple the Yuasa battery in another iMiev forum post:

http://www.electric-vehiclenews.com/2014/11/next-generation-gs-yuasa-lithium-ion.html

Thanks, Phximiev . . .

I'm one of those rare birds who actually likes to hear about new battery developments. Who to say if
this is going to be GS Yuasa drop-in replacement for the LEV50 or not (same form factor, though, with
the terminals along the long narrow edge,) but it's good news that they are looking ahead.

Lithium sulfur is an interesting one. A couple minute's walk from my workplace at the University of Arizona
is the Chemistry Department's lab, where they're conducting research into lithium sulfur cells. I was lucky
enough to get a private tour with a few other local electric car geeks a couple years ago . . .

http://www.sciencedaily.com/releases/2013/04/130414193441.htm

The big challenge with LiS, apparently, is cycle life. Early iterations could only recharge a hundred or so times.
Now, they're upwards to a thousand cycles or so and beyond. Google "lithium sulfur" and you'll
note a lot of different labs are working on this.

 

[DonDakin]

So I started toying with the 18650 cells also.

In a loose configuration I got 24 in a lev-50 box. At 3 AH per cell that's 72 AH or about 44 % more then a stock imiev about 23KHW. Also the weight would be 44.6 g *24 or 1.07 KG about 38 % lighter then stock.
If the battery could support 2C discharge which is very reasonable that would not be too bad.....

http://imgur.com/a/SOIo4

Don.....

 

[JoeS]

So I started toying with the 18650 cells also. In a loose configuration I got 24 in a lev-50 box. ...

I didn't have a feel for the LEV-50 size. This puts an interesting spin on everything. Looking promising…

Arbitrarily finding this Panasonic 18650B spec:
http://www.batteryspace.com/hi-powe...2-24wh---ncr18650b-0-93---un-38-3-passed.aspx

Didn't see whether this cell has a built-in fusible link or not.

The maximum rated discharge current is 6.8A
6.8A * 24 cells = 163.2A, which is just about the maximum the i-MiEV draws, so that's OK.

The charging and discharged voltage and current characteristics are within our lev-50 parameters.

If the form factor was to be the same we would thus have a bolt-in replacement with no BMS changes needed.

Let's arbitrarily say the 18650 price is $5/cell

24 * 88 * $5 = $10,560 :shock:

No wonder Elon Musk is working at reducing the cell unit cost.

What if someone wants to go into business in five years rebuilding i-MiEV packs...

Let's say in five years the price will drop to $0.50/cell ($1056/pack), and let's say these cells could be interconnected and put into a cost-effective LEV-50-size package... methinks the labor and shipping costs might make this concept prohibitive at the pack level. Nevertheless, for us hands-on types who could rebuild our packs ourselves, how much would we be willing to pay for the guts of a 23kWh replacement pack for our i-MiEV?

 

[Phximiev]

Ok, found a new page for Mitsubishi:

http://www.gs-yuasa.com/us/topics/index.html

And found these on the site:

A battery announcement: http://www.gs-yuasa.com/us/topics/pdf/20150303e.pdf

and a Tesla Powerwall type of thingy: http://www.gs-yuasa.com/us/topics/pdf/20150127e.pdf

Quite interesting.

 

[tigger19687]

What about heat ? If you pack them all in there, is there enough to allow for all the other stuff and heat exchange ?

 

[jray3]

Ok, found a new page for Mitsubishi:
http://www.gs-yuasa.com/us/topics/index.html
And found these on the site:
A battery announcement: http://www.gs-yuasa.com/us/topics/pdf/20150303e.pdf
and a Tesla Powerwall type of thingy: http://www.gs-yuasa.com/us/topics/pdf/20150127e.pdf
Quite interesting.

THX Phx!

In a parallel vein, I ran a few numbers given the bottom price of a used i-MiEV down around $6500 now, while good used LEAFS are now down near $12k, and a collision-salvage LEAF can hardly be had for less than $6k!? Just pricing the batteries, that's $406/kWh for i-MiEV and $500/kWh for a used LEAF (generously assuming that the used LEAF still has 24 kWh). The price for salvaged LEAF packs alone from Hybrid Auto Center is now at $271/kWh and up.

http://www.hybridautocenter.com/HAC4/index.php?option=com_hikashop&ctrl=product&task=show&cid=88&name=11kw-h-battery-block-182v-60ah-from-2013-nissan-leaf&Itemid=605

How's that compare? Well, with new CALB cells still around $1.30/Ah, that's about $481/kWh for new, naked cells, versus $406 for used cells with a good car wrapped around them.
:roll:

 

[Don]

I am really hoping that my gamble plays out, that when the OEM battery pack goes out, i will be able to replace it with something that will allow a longer range. My hope is that there will be some aftermarketer that will see value in making higher density packs for older leafs and mievs and keep them going.

Possibly, but I fear the market may be too small for anyone to offer a larger pack designed to fit an iMiEV. There weren't all that many sold to begin with and the number of owners with an 8 or 10 year old car with 100K on it willing to shell out several thousand dollars for a new battery pack may be so small it wouldn't make sense for anyone to tool up to make new packs specifically to fit it

I would ask you how many cars you've bought that you're still driving ten years later, but I've actually done that half a dozen times already, so you might actually still be driving your car come 2022 - I hope one or both of mine will still be running then, but at our going rate, neither of them will have 100K on them by then

Don

 

[PV1]

Doing some calculations, and given the size of the LEV50 cells, a box with the same dimensions can fit roughly 80 Ah of 18650 cells, boosting the range from 62 to 100 miles. I would imagine someone would build custom packs to keep these older EVs on the road. Whether or not the owner would pay to have a battery re-packed is less likely, but assembling large cells with 18650 cells should be pretty straightforward, albeit with all cells in parallel, not series (each group of cells are wired in series, though). The 18650 cell is quite capable.

I'm having trouble keeping my pack cool with this heat wave these last couple of days. The car, only driven 35 miles all weekend, has a pack temp of 93 degrees F. Can't do much long range driving this week.

 

[zzcoopej]

assembling large cells with 18650 cells should be pretty straightforward, albeit with all cells in parallel, not series (each group of cells are wired in series, though). The 18650 cell is quite capable.

There is a company in Sweden called Vtech Tuning who have disassembled an Outlander PHEV battery pack (very similar to iMiEV one) and are planning to replace the contents with 18650's. Their calculation was that it would give a 50% increase in range. Not sure their progress, I think the biggest issue will be tricking the BMS into still charging it, considering all the voltage and temperature sensors inside the pack.