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Discussion Starter · #1 ·
I know I've asked a similar question before and got some interesting answers but I was wondering... if there was a better battery invented that had a higher charge capacity and more power output, would it be possible to swap out the batter with the Fisker?

I know some of you brought up software issues but I'm talking about switching power not at the interface end but at the very point of power exchange ie. where the simplest exchange of amps occur... even if this new technology didn't have the exact specs that the current battery uses, can't there be a simple step up or down transformer put into place to make it work?
 

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Very interesting question but not many answers to it. Has anybody some ideas about that?
 

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wait for the 2nd (or 3rd?) gen Nissan Leaf, the rumors say they have doubled the capacity.
if that's true, it's will be the starting point for making that new technology mass market and will lower cost in order to integrate it with existing EVs
 

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Discussion Starter · #4 ·
Have you guys seen this new Quant car powered by nanoflowcell technology? 900hp, 0-60 in 2.8sec and range up to 600km... so ya, the Karma could be a heavier car but why can't we use other battery technologies and have them fitted inside our car? Like I said, I realize there are software issues but I'm talking about power at the source, before all electronics get hooked up.
 

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Have you guys seen this new Quant car powered by nanoflowcell technology? 900hp, 0-60 in 2.8sec and range up to 600km... so ya, the Karma could be a heavier car but why can't we use other battery technologies and have them fitted inside our car? Like I said, I realize there are software issues but I'm talking about power at the source, before all electronics get hooked up.
It's certainly interesting, but it's a good bit more different from the Karma than battery tech and software. For one thing, the Quant uses four separate motors, one for each wheel, with a peak HP of 227 each and an operating HP of 160 each. It's the peak 911HP and 8,552 lb-ft of torque (not a typo) that give it the acceleration, not the 600V battery.

It's all a bit moot anyway; the Quant e-Sportlimousine is a technology demonstrator not a real car. It will never enter production although some if its ideas may be productized over the next couple of decades.

Lots more here:
http://www.topspeed.com/cars/others/2014-quant-e-sportlimousine-ar162177.html

Key conclusion from the article:
At this point the e-Sportlimousine is only a test vehicle for the nanoFLOWCELL technology with no plans to move it into full-scale production as of yet. However, with the immense growth and advancements in its technology, it’s possible we can see this type of system utilized in the next few decades. So check back with TopSpeed in 20 years or so for any updates.
 

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Discussion Starter · #6 ·
interesting! but again, I know it's very different in design but those wheels all get power from one main battery source just like our Karma, no? Why can't we use other batteries that have a greater power density as long as they fit into the space that's currently taken up by our battery pack? Forget everything else, electronics, software etc., there must be a single point where electricity leaves the place of storage and only beyond that is when all of the complicated stuff takes over. But before that point, why can't we use different types of batteries?

Cheers,

Pat
 

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Form a non-battery expert's perspective, if someone made a 40KWH battery that is the exact same size and weight as the current battery, has the same software interface, operates at the same voltage and same temperature band as the current battery using the same heating/cooling systems, and has the mounting points and connectors all in the same spots, it should be possible to take out the existing battery and slip in the new one, and just get double the current range. But it never seems to work that way. Newer technology batteries always seem to have different operating requirements, voltages, different heating or cooling requirements, or in some other way have very different requirements that makes it very difficult to just unplug the current battery and plug in the new one.

Another potential obstacle is the very limited number of Karmas that are on the road today. Building a replacement battery to the Karma's specifications would be wildly uneconomical when you are only talking about 1800 cars worldwide. Are you really willing to spend $50K for a new battery to get more range?

I suppose it would be possible for A123 to improve the efficiency of the internal battery modules so that as the modules age out and are replaced, they can be replaced with newer modules that provide more capacity, which would in turn provide more range, but much more modestly and over time.

Turns out that this really is rocket science.
 

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Discussion Starter · #8 ·
Oh it's definitely complicated which is why I think the company got taken out by the Chinese which still irks me.

but just to be clear what I'm inferring... I'm talking about the power source before software touches and i'm guessing the heating/cooling infrastructure surrounds the battery and isn't integral to it. The voltage can be changed to suit the car's current system at the point of energy release. So the transformers and 'plug' that engages the battery to the system definitely needs to be created but the power source itself should be able to be swapped, or that's what I'm hoping.

The shape and size of the battery is definitely an issue but as they come in cells, I wonder if they can be packed differently. The technology is in the materials and how these cells are built vs size and shape. What I'm really hoping is that someone comes up with a battery with a greater capacity but is smaller than the one we have now so we can just place them inside the space and have brackets put in place so they don't wiggle around.

Anyways, I'd definitely offer my Karma up as a guinnea pig so if someone knows of a battery pack that's better than the A123 one we have now, I'd definitely be interested in hearing about it and I will contact the company to see what they can do. It's an issue all of us will end up having to deal with within the next few years...
 

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I see it like Hockeydad and am waiting for some new technologies coming which fits in our cars. I am not a specialist in electricity but let it put very easy that way: If I would have bought an electric bunny 15 years ago with a battery it would have hopped around for let's say half an hour. If I would put in the same bunny a today's battery it would hop around for may be 45 to 60 min. The same bunny, same connections to the electric "engine" and everything around the same. Just newer and better battery technology. Why shouldn't' this happen to car batteries such as our Karma battery?
 

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I see it like Hockeydad and am waiting for some new technologies coming which fits in our cars. I am not a specialist in electricity but let it put very easy that way: If I would have bought an electric bunny 15 years ago with a battery it would have hopped around for let's say half an hour. If I would put in the same bunny a today's battery it would hop around for may be 45 to 60 min. The same bunny, same connections to the electric "engine" and everything around the same. Just newer and better battery technology. Why shouldn't' this happen to car batteries such as our Karma battery?
Because the battery you used in the bunny 15 years ago is the same standard battery that has been used by millions of other devices. There is really very little standards as of yet in car batteries in terms of size, shape kW, etc....best we can hope for is new FK using the same batteries and selling enough so there enough demand and price points that we can upgrade and someone can make money doing it.
 

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well you can just use the same batteries that are in the Tesla they are mass produced and in bulk cost about $1 (see for example: http://www.alibaba.com/product-detail/NCR18650B-3-4Ah-Highest-Capacity-18650_1702288953.html)

Also:

http://www.orbtronic.com/batteries-chargers/panasonic-3400mah-18650-li-ion-battery-cell-ncr18650b

to replicate the 20.1KWh battery in the Karma you would need about 1,652 of these - that would weigh about 167 pounds. so theoretically 3200 of these would weigh only 340lbs and give you twice the range. And with Elon building his gigantic factory to turn out these little batteries - expect price to plummet even more. our battery technology may be better in some ways - but this battery technology will win the day - simply because it will (and currently is) cheap.

I am not suggesting that is as easy a sunday stroll - but theoretically there is nothing stopping anyone from buying the cells for $1 a piece - (plus you need controllers) stringing them together in a form factor that matches the karma battery (**** just use the karma battery take out all the modules) - I don't know about the software side and what you would need to do to get it to work.
 

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From a rough calculation of a spare battery enclosure I have laying around the shop I measure a volumetric capacity of 260L or so (without the wing portion). The Karma uses 315 cells I believe so this is a cavernous amount of space for such a few amount of cells (even taking into consideration the thermal systems necessary so that the pack can perform optimally). The pack that closest resembles the Karma pack is that of the Spark EV (21.3kwh, 336 prismatic cells etc). The interesting thing is the volumetric capacity of the Spark A123 pack is only 133 liters.

http://www.gmgoelectric.com/product/public/us/en/electrification/batteries.html

Taking into consideration Fast DC provisions have been implemented in the Spark design it would not be unreasonable to assume that the C heat dissipation is adequate in the smaller enclosure and in the same ballpark as that of the Karma's enclosure.

IMO it would be the path of least resistance to use some variant of the Spark EV modules in the Karma enclosure to increase the all EV range. From a technical standpoint this would be the easiest retrofit barring a clean sheet pack re-design.
 

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Discussion Starter · #14 ·
Wow Smooth! You really know you're stuff. Now this is what I was hoping to get from this thread... some good sharing of thoughts to try and resolve a problem we will ALL have at some point. We can't depend on anyone making a new battery for the few thousand Fiskers on the road so we are left fending for ourselves.

Please, please, keep this conversation going, share thoughts and let's try and put our energies towards a solution rather than trying to find arguments of why it won't work.

So just to keep things on track... we're not looking to replace any software, temperature control system etc., we're simply trying to look at replacing the rechargeable power source leaving everything else intact. There could be issues of different voltages so an adapter/transformer may be required but that should be about it, as long as it can fit in the space.

Hopefully we can look at more power and range for the same weight or the same power and range but less weight which still means more range :)

Would someone be able to do a little experiment and hook up these batteries in a mini-pack, enough just to power a few electronical systems at first to see what issues and what needs to be done to connect the new power source to the car? Or is that not the right first step to do?
 

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Discussion Starter · #15 ·
Sorry, I mixed up the two responses...

Smooth is saying that we should use the Spark EV batteries rather than the Asulil's idea of taking Tesla batteries and creating our own pack.

So my first response should have been to Asulil's where I was wondering if there are members out there who could look at creating our own pack of Tesla batteries if we believe the Tesla batteries are superior to the Spark EV batteries and test a mini-pack to see if they can work with the Fisker Karma on a small scale basis and then go upwards from there, testing for heat etc and seeing if our current temperature control systems are adequate.

My second response should have been to Smoothoperator where I wanted to ask if we could hook up 2 of the Spark EV batteries together given we have almost the space to get two of them in there? Also, what's the range on one of these Spark EV batteries?
 

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First step would be to get some more in-depth technical information about the Spark EV battery. It is my assumption that it uses a variant of the AMP20 cell used in the Karma (7P3S layout).

The Karma consumes in excess of 500wh/mi but lets use this figure for a normal case scenario. A few assumptions first:


  • We are able to make contact with someone with knowledge of Catia that is able to optimize the Karma enclosure for these modules
  • These are the same modules that are used in the Spark EV. If this is the case, which is likely since the Spark EV uses 4 modules. With each module producing 5.38 kwh that puts the Spark at 21.52 kwh which is very close to the manufacture stated 21.3 kwh.
  • The assumption that each module takes about 35L (1.2 Cu Ft) of space. If this assumption is correct then about 7.4 of these modules could fit in the Karma enclosure.
  • If the above assumption is close to reality then it should be possible to get 39Kwh of power out of the pack (probably 36 or so usable). This will mean a range of roughly 72 real miles or 92 "Fisker miles". I read somewhere that it costs GM something like $400/WH so that would put the complete module price at $15k or so.
These projections and ideas are based heavily on assumptions which may or may not be valid due to the limited information I have on these packs. If someone is willing to do the legwork and collect more information I would be happy to help.
 

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$15K seems like a lot. I am 100% all for discussing any idea on how to improve our cars - i think its great and am really appreciative of all the informed comments.
Using the spark system certainly seems more straightforward - but at $15K ? when you can buy the same amount of "energy" with the tesla batteries for around $5k.
 

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$15K seems like a lot. I am 100% all for discussing any idea on how to improve our cars - i think its great and am really appreciative of all the informed comments.
Using the spark system certainly seems more straightforward - but at $15K ? when you can buy the same amount of "energy" with the tesla batteries for around $5k.
The ESS of a Tesla requires much more management and is incompatible with the Karma thermal system. The engineering cost to put such 18650 batteries in a Karma enclosure, along with the thermal systems that would need to be installed/engineered would be astronomical. The whole car would need to be re-engineered. This along with the new BMS and custom engineering and integration work needed to implement a completely different battery chemistry make it cost prohibitive to go that route. It would cost millions. From my experience it is best to use battery technology that is closest to what the car was designed for. We are talking about off the shelf modules used in other cars vs custom engineering a small form factor battery that Tesla has poured many hundreds of millions into perfecting. Heck even Rimac uses these A123 batteries and they are an extremely lean performance EV company that does most everything in house.
 

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The ESS of a Tesla requires much more management and is incompatible with the Karma thermal system. The engineering cost to put such 18650 batteries in a Karma enclosure, along with the thermal systems that would need to be installed/engineered would be astronomical. The whole car would need to be re-engineered. This along with the new BMS and custom engineering and integration work needed to implement a completely different battery chemistry make it cost prohibitive to go that route. It would cost millions. From my experience it is best to use battery technology that is closest to what the car was designed for. We are talking about off the shelf modules used in other cars vs custom engineering a small form factor battery that Tesla has poured many hundreds of millions into perfecting. Heck even Rimac uses these A123 batteries and they are an extremely lean performance EV company that does most everything in house.
+1

you don't want to use Tesla approach. Among other reasons, check out YouTube videos of LiCo fires.

What we are doing is junking the gasoline side altogether and fitting Enerdel batteries into the original pack and the spaces that are cleared in the front. A quick photo of our project below. You can see a native pack on the right.

Replacing cells in the main pack might seem simple but it isn't. Couple of reasons:
1. Central BMS expects certain signals from the cell-level BMS boards. So you want to keep the same BMS electronics. This means you need the same cell count. This means that you are now constrained on the AH per cell. This means that you might not be able to realize any gain in pack size after all as cells come in very discreet capacity levels
2. cell-level BMS will be designed to fit the module that's in the car now. It won't fit (physically) on anything else.
3. If there is any difference between the chemistry used in the car and chemistry you are using, BMS will not be happy and may result in you not being able to utilize full capacity of your new battery
4. You would be lucky to achieve 50% space utilization of that 260 liters. Connectors, cables, cooling, BMS, cell hardware, etc. Datasheet for A123 cells used in Fisker. You will notice that at the cell level, these have ~250WH/liter density. If you could utilize 100% of 260 liters available, you would have a 65kwhr pack. That would be nice. There is a reason why it's not 65kwhrs...

My [well informed] assessment is that it will be very hard to achieve anything beyond 25kWHr usable in the native pack space without going to dangerous chemistries such as Tesla's.

V
 

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+1

you don't want to use Tesla approach. Among other reasons, check out YouTube videos of LiCo fires.

What we are doing is junking the gasoline side altogether and fitting Enerdel batteries into the original pack and the spaces that are cleared in the front. A quick photo of our project below. You can see a native pack on the right.

Replacing cells in the main pack might seem simple but it isn't. Couple of reasons:
1. Central BMS expects certain signals from the cell-level BMS boards. So you want to keep the same BMS electronics. This means you need the same cell count. This means that you are now constrained on the AH per cell. This means that you might not be able to realize any gain in pack size after all as cells come in very discreet capacity levels
2. cell-level BMS will be designed to fit the module that's in the car now. It won't fit (physically) on anything else.
3. If there is any difference between the chemistry used in the car and chemistry you are using, BMS will not be happy and may result in you not being able to utilize full capacity of your new battery
4. You would be lucky to achieve 50% space utilization of that 260 liters. Connectors, cables, cooling, BMS, cell hardware, etc. Datasheet for A123 cells used in Fisker. You will notice that at the cell level, these have ~250WH/liter density. If you could utilize 100% of 260 liters available, you would have a 65kwhr pack. That would be nice. There is a reason why it's not 65kwhrs...

My [well informed] assessment is that it will be very hard to achieve anything beyond 25kWHr usable in the native pack space without going to dangerous chemistries such as Tesla's.

V
Interesting project!

Here is my take on your points:

1. From my brief conversations with A123 engineers I believe the pack hardware in the Karma is not proprietary to this vehicle and this architecture is used in all AMP20 Packs/Modules. The only thing proprietary is the shape of the battery enclosure and some of the external HV connectors. The Battery Control Module (BCM) is the same as on the Spark EV (with just a different flash than the Karma). It is possible to flash this component to correlate with the correct cell voltages, AH etc. A simple data dump from Canalyzer provides quite an informative look at how customizable the A123 BCM is.

2. For the actual modules you can replace (or flash) the monitor balance boards that correlate with the correct cell specifications. The Spark EV uses this same setup of MBB's inside the Cell Modules that communicate with the BCM. I think all that many are looking for is a ~35-40kwh pack. Anything else would make the car very heavy.

3. I think by replacing the Amp20 Prismatic pouches with higher capacity ext ones inside the modules itself may end up being the most cost effective solution.

I have been trying to find some information on the AMP20 Modules (i.e dimensions, weights, capacities, cooling etc). Do you have any information on these energy modules?
 
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