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...LiFePO4 cells and NMC cells. I think the LiFePO4 cells would be a much better fit for our cars, and the voltage works out more cleanly...
NMC can handle high temperatures but LiFePO4 cells take high regen better. Except for baking in a sun-drenched parking lot, I don't see the car straining lithium cells enough to warm them much. IR vs. NiMH is tiny from what I've seen.

There are 3 local Insights here with tired packs and an interest in lithium-ion. The radically smaller self-discharge vs. NiMH is a wonderful thing. I've been using Peter's OBDC&C for a few years now... I assumed simply telling the car what the SoC is based on voltage would address a higher-than-OEM capacity pack (and allow PHEV-type use).

What I'd be interested in is a pack maybe 3 - 4X the OEM capacity of the same weight and size (or close), partly since the Insight just isn't designed for lots of extra weight, and let the IMA use it PHEV-style to stretch the mpg massively while making life easier on the engine, and knowing the invertor might want additional cooling.

I've read over this thread and much of the lithiated Insight thread and am quite impressed with the thoughts and progress that's been made.

Roger
 

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It is easy enough to make a pack like you are describing.
There have been great advances with spoofing signals, etc so car will accept the pack.
You could begin the project this afternoon.

The real issue is most folks are not willing to pay the needed cost to do the job.

$3,000-$6,000

Are you interested in a pack that is 3 to 4 times the capacity of existing pack and the same weight, and cost 1.5 to 2 times the cost of a stock pack?
 

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I think that with Fit LTO conversions we are as close to drop in as we are going to be anytime soon. The required 3 packs fit within the IPU and are easy to connect with easily fabricated 4AWG cables. The conversion is so simple that anyone with a soldering iron and woodworking tools can do it - OK throw in a Dremmel tool for good measure. Most of the hard part in making a mounting system and Atheos has shown that the mounting plate can be made of plywood.

It requires the relatively simple installation of two electronic trinkets from Peter - the fooler and the BCM interceptor, which he will preprogramed.

This configuration performs beautifully in the car and runs "naturally" in the 168-172V range, just slightly above the cell nominal voltage of 2.3V/cell.

A better approach may come along, but then that has always been true and always will be. There will never be a commercially available conversion with the luxury of warranty and support, so get over that idea;)
 

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Using the fooler and interceptor opens up the door for a wide variety of batteries.

While I am supportive of any lithium replacement I'd hate for people to think that they must choose LTO, or that it is the only option.

I am concerend about folks following LTO for a few reasons.Dor example, it is not a well supported chemistry, has lower energy density than other chemistry, and the scarcity of the packs.

There are other packs that likely fit nicely into the hatch that are more readily available. It just takes someone to give it a go and then hopefully share their experience.

I have stack of lithium packs , but they, too, are obscure so if I did it it would just be another one-off.

Everything to make your own replacement lithium pack exists today. It just takes the willingness to try it rather than waiting for someone else to go first or lay it all out for you ahead of time.
 

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The real issue is most folks are not willing to pay the needed cost to do the job.

$3,000-$6,000
I'm working on acquiring another Insight this weekend. I'll be dropping in Lithium LTO batteries, and plan to do the conversion for under $1200. You can do these without too much modification.
 

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While I am supportive of any lithium replacement I'd hate for people to think that they must choose LTO, or that it is the only option.

I am concerend about folks following LTO for a few reasons.Dor example, it is not a well supported chemistry, has lower energy density than other chemistry, and the scarcity of the packs.

There are other packs that likely fit nicely into the hatch that are more readily available. It just takes someone to give it a go and then hopefully share their experience.
I definitely agree, LTO is not the only option.

But in my opinion, it has many advantages over Li-ion:

- Order of magnitude higher life cycle (400-1200 cycles for Li-ion, 6000-20000 for LTO). Li-ion has comparable-to-worse life cycle than Ni-MH. If I'm buying a new pack for my Insight that is more expensive than the Ni-MH option, I want it to last significantly longer than the stock option.

- Higher operating temperature range. Li-ion must only be charged between 0-45C. Charging at lower than 0C causes Li-ion cells to plate, which reduces capacity and causes early cell failure.
The temperature range for Li-ion and Ni-MH is comparable, but Ni-MH can be charged below 0C as long as it is very slow, whereas you can't at all with Li-ion.
LTO has a much larger operating range (generally down to -20C or better).

- Safety. Li-ion batteries are very volatile and cause violent fires when they fail. LTO is much, much safer in that regard and doesn't explode or catch fire when damaged. Check out this video of testing Toshiba's LTO cells.
No offense to the awesome members on here, but I'm somewhat wary of putting a battery controller in my car that hasn't been thoroughly reviewed and tested for safety like an OEM's battery implementation would be. I don't want a bug or hardware failure to cause the lump of Li-ion in my trunk to catch fire.

- LTO has been around longer than you think. It's just now starting to show up more and more, and it's proven technology.


I think all this alternate battery pack development is awesome and I'm super excited about it. I'm definitely going to be using somebody's solution eventually! But I'm only going to be using LTO cells.
 

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Using the fooler and interceptor opens up the door for a wide variety of batteries.

While I am supportive of any lithium replacement I'd hate for people to think that they must choose LTO, or that it is the only option.
True, Peter's trinkets will work with any conversion.

I was simply making the case that the Fit LTO was the best option I can see at this point in time. Advantages; they come in a conveniently built package which simply has to be bolted down to something, like a mounting plate, they are electrically and mechanically sized such that 3 packs provides the proper operating voltage AND a 4X capacity and fits into the IPU, they are alleged to have long operating lifespan, they are probably the safest chemistry to work with, the 72(3 pack)cells configuration will integrate smoothly with the Orion BCM if desired.

I am concerend about folks following LTO for a few reasons.Dor example, it is not a well supported chemistry, has lower energy density than other chemistry, and the scarcity of the packs.
Some truth, but......
What is support for a chemistry? Which ever USED cells or packs we use will be unsupported. They will never have warranty replacements, or a customer service number for advice.

It is true of course that LTO has lower energy density, but is an acceptable compromise, to me anyway. It adds about 40 pounds max to the rear of the car. I fitted Scotts springs and I have had no negative impact from the slight additional weight. To me personally, it isn't a problem.

There are other packs that likely fit nicely into the hatch that are more readily available. It just takes someone to give it a go and then hopefully share their experience.
Well name them!!

The Leaf cells would be a nice fit, but the required modification is prohibitively and probably dangerous, IMO. The Ford Energy seemed attractive until I realized at last year Insightfest that they don't fit the IPU without modification. The 2013+ Honda Civic Hybrid, which I considered, is a very nice package and can be made to fit fairly easily, BUT it has only 4.5Ah capacity, about the same as the stock battery. There has been a lot of talk about the Sonata packs, but that idea is untested. (Want to build one and try it?) BTW, if my info is correct it will have a fairly modest capacity.

Whatever option one uses, it will not have a BCM unless someone designs a reliable one (unreliable is worse than non) and that may add too much cost and complexity.

If we wait long enough there will probably be more attractive options in a system sense, but I don't have any more time to wait;)

I have stack of lithium packs , but they, too, are obscure so if I did it it would just be another one-off.
Anything anyone does with gen1 Insights is going to resemble a one-off. There is going to be no uniformly available drop in conversion. There are just too many things against it. Rather than list all the things against such a convenient solution, I'll just list the two biggest ones, IMO. First there will never be agreement of what the "right" battery and design is to be. Second, no sane individual is going to take on the liability of building special batteries and selling them into an unknown environment. That is a receipt for personal financial ruin and serious government intervention and trouble.

replacement lithium pack exists today. It just takes the willingness to try it rather than waiting for someone else to go first or lay it all out for you ahead of time.
Ain't going to happen - see above. The LTO "school" is growing because it is so easy and so promising. There are others getting in as we speak. Is it perfect? Certainly not. Is it the immediate solution? Well it is pretty darn attractive.
 

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The earlier comments about "lithium ion" vs. LTO seem odd... LTO anode vs. graphite anode, both are lithium ion. For the cathode you can do whatever.
LiFePO4+LTO for the SCiB cells makes minimum voltage (much of why they're so safe) but maximum ruggedness. Use of LTO anodes is growing, but graphite anode is easier to make (but with the copper substrate does rely on a protective SEI layer meaning no Vmin flexibility).

...Whatever option one uses, it will not have a BCM unless someone designs a reliable one (unreliable is worse than non) and that may add too much cost and complexity... The LTO "school" is growing because it is so easy and so promising. ...
With SCiB cells you could get away with no BMS for maybe quite awhile, longer than with other formulations, but any LIB pack without a good BMS can eventually be considered an unexploded bomb begging Murphy's Law to apply itself. My main car now is a '15 Volt (I was sick of quickly-tiring NiMH D-cells), and I use the MyGreenVolt app every trip, and it shows a min, max and mean cell voltage variation of typically 0.02V, usually 0V, showing what a serious BMS can do (assuming its voltage readings are that reliable... but even if with a little accuracy-limited variation that's still very good).

As for the $3k-$6k cost, thank you for reminding me of reality... But if one settles for something close to current pack capacity just using Prius NiMH prismatics seems in many ways more reasonable... Heavy as OEM cells, and mechanically and connection-wise work certainly has to be done, but voltage-wise and balancing-wise they're a perfect drop-in and and are electrically very tough and would terminate the nemesis of quickly tiring high-IR D-cells. And they aren't hyperexpensive, and don't use nearly as issue-laden an electrolyte as any lithium-based cells. With smaller capacity packs, meaning HEV-type high power cells, the cells have to be able to tolerate high C-rates very reliably which does regen-wise restrict one to LTO and/or LiFePO4, or simply Prius NiMH prismatics however unfun that may seem.

All that said, the R&D scientists at my workplace (a high-end lithium-ion relatively small batch plant) have great respect for Toshiba SCiB cells.

Roger
 

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LTO anode vs. graphite anode, both are lithium ion. For the cathode you can do whatever. LiFePO4+LTO for the SCiB cells makes minimum voltage (much of why they're so safe) but maximum ruggedness....
My understanding is that the SCiB cells are NMC + LTO, not LiFePO4... The high energy cells are one NMC formulation/ratios, while the high power are another. I'm sure I read this (NMC positive electrode) in more than one place, like different research papers... Oh yeah, plus, if the cathode were LiFe, the voltage would be even lower - I think you drop the nominal -1.5V to make up for the titanate negative electrode - so say NMC nominal is 3.8V minus 1.5V=2.3V nominal...
 

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As for the $3k-$6k cost, thank you for reminding me of reality...
I think that was Eric's estimate for a drop-in replacement, but since it isn't going to happen, the number doesn't mean much. The cost of copying my design(owing a great deal to insight buyer who was first), including the purchase of the LTO packs, is about $1500-$1800.

But if one settles for something close to current pack capacity just using Prius NiMH prismatics seems in many ways more reasonable...
No arguement there, and probably even cheaper. As you know, we had a running example of that approach last year at the Spring Mid-Atlantic meet. Unfortunately the design and management isn't documented in a thread, and the designer has disappeared from IC.
[/QUOTE]
 

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The only way we will know if other batteries fit is if someone tries them.

But since there is a LTO conversion it may hamper anyone trying something else.

Not sure how much supply there is of these LTO cells.
Hopefully enough to staisfy those who are interested in doing the conversion.
 

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But since there is a LTO conversion it may hamper anyone trying something else.
Someone will come up with something using later and more readily available batteries, but it will again be a one or two off situation. Engineers will always engineer;)

Not sure how much supply there is of these LTO cells.
Art at GreenTec told me a couple of weeks ago that he had more. I will probably offer my surplus in a couple of months. I have 11 packs and only plan to use 4 - 3 plus a spare.
 

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... Unfortunately the design and management isn't documented in a thread, and the designer has disappeared from IC.
Figuring out how to fit Prius prismatics into the Insight case, hooking up the cells to the connections board and adding anti-swelling straps can be figured out. That seems extremely simple vs. switching to lithium-based cells. We already know it can be done.

A spare Insight case, some known-good Prius cells, some good bus bar / connection strap material and figuring out the best anti-swelling straps arrangement should be all that takes... should. My Insight and a couple local friends' Insights are all due for replacement cells already, and that's what I was planning on using for one or two of them (or all 3 if need be).

I was thinking the SCiB cells were 1.7V. 2.4V does suggest a higher-voltage cathode.

I was hoping to find a good-quality BMS had been settled on, since the conversion depends entirely on the ability to add individual cell voltage management (and yes, funding).

Roger
 

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Figuring out how to fit Prius prismatics into the Insight case, hooking up the cells to the connections board and adding anti-swelling straps can be figured out. That seems extremely simple vs. switching to lithium-based cells. We already know it can be done.

A spare Insight case, some known-good Prius cells, some good bus bar / connection strap material and figuring out the best anti-swelling straps arrangement should be all that takes... should. My Insight and a couple local friends' Insights are all due for replacement cells already, and that's what I was planning on using for one or two of them (or all 3 if need be).
Please, start a thread about your project progress and post pictures :D
 

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Figuring out how to fit Prius prismatics into the Insight case, hooking up the cells to the connections board and adding anti-swelling straps can be figured out. That seems extremely simple vs. switching to lithium-based cells. We already know it can be done.
Roger, have you not been reading my conversion thread;)

We already know that the LTO conversion can be done also. At this point there are two or three cars running and more planned. With Peter's trinkets, which are simple and cheap, the only real work is the mechanical part of the fabrication, and that has been worked out. The LTO packs are very convenient as they already have bolt-down points and they are already "strapped." The wiring complexity of the two approaches is about the same. Peter once remarked, with a wink and a grin, that "If Jim can do it, anyone can do it."

spare Insight case, some known-good Prius cells, some good bus bar / connection strap material and figuring out the best anti-swelling straps arrangement should be all that takes... should.
Oh, I think you are perfectly capable of doing the conversion and that it will be a quality result. It may turn out to be several hundreds of dollars cheaper so it has that advantage. It will be interesting to watch. It is just too bad that our friend disappeared because he had done a first rate job and now the information is all lost near as I can tell.

I was thinking the SCiB cells were 1.7V. 2.4V does suggest a higher-voltage cathode.
The spec operating range for the Toshiba SCib cells is 1.5-2.7V but there is little capacity at the ends of the discharge curve. Derating to 2.0-2.5V, I get a capacity which is 4X the stock pack.

I was hoping to find a good-quality BMS had been settled on, since the conversion depends entirely on the ability to add individual cell voltage management (and yes, funding).

Roger
Be careful of BMS's. Ian makes a convincing case that no BMS is far better to a poorly designed and unreliable one, because that can ruin your battery. The Orion 2 is commercially available and most likely reliable, but it is very costly. If you run without BMS for a while and do manual monitoring, I do think a supportable BMS might emerge.
 

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Roger, have you not been reading my conversion thread;)

We already know that the LTO conversion can be done also. At this point there are two or three cars running and more planned. ...
I speed-read through the pages, missing some early material and probably forgetting some later material. I do remember the SCiB modules having their own mechanical strength from the last Meet I could attend.

It would be nice to have an example of a, umm, Prinsight? pack, but it can figured out with time, which I don't seem to have much of right now, eventually maybe.

The spec operating range for the Toshiba SCib cells is 1.5-2.7V but there is little capacity at the ends of the discharge curve. Derating to 2.0-2.5V, I get a capacity which is 4X the stock pack.

Be careful of BMS's. Ian makes a convincing case that no BMS is far better to a poorly designed and unreliable one, because that can ruin your battery. The Orion 2 is commercially available and most likely reliable, but it is very costly. If you run without BMS for a while and do manual monitoring, I do think a supportable BMS might emerge.
So if one is willing to shell out $$$$$$ it's totally doable... I agree about a BMS... It has to work or don't go there. The Insight would be so absurdly gentle to those good, sturdy cells that they shouldn't whack out for awhile, especially if avoiding the 2.0-1.5V SoC dropoff.

Roger
 

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So if one is willing to shell out $$$$$$ it's totally doable... I agree about a BMS... It has to work or don't go there. The Insight would be so absurdly gentle to those good, sturdy cells that they shouldn't whack out for awhile, especially if avoiding the 2.0-1.5V SoC dropoff.

Roger

I gave some approximate cost numbers back in post #913. It is most likely less than a new Bumblebee.
 
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