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Could battery swapping eliminate concern for battery degradation?

7K views 18 replies 12 participants last post by  adric22  
#1 ·
The current flap over LEAF battery degradation got me to thinking - this issue might spur a deeper interest and commitment to the concept of battery swapping for pure EVs.

I've been dismissive of Better Place and remain skeptical of its viability, but if LEAF owners were able to swap their batteries for another, their concerns and fears over degradation would disappear.

I'm thinking the BP concept might work best as an occasional service stop rather than an every day affair. Cost of a swap would be more than an everyday stop but far less than purchasing a brand new battery, far less than an ICE engine overhaul/swap.

Occasional swapping made easy and affordable could very well be turned into a positive selling point for pure BEVs. However, I'm not sure auto manufacturers would necessarily benefit, for it could mean consumers would hold onto their vehicles longer.
 
#4 ·
I agree with Stuart22... Better place would eliminate the concern about the battery charge fading over time.

Living in Arizona, I feel I am limited in how much I can protect my own battery from the heat, no matter how much I try. I already had 2 batteries get cooked in My Honda Civic hybrid. A certain level of protection from Better Place would definitely make me feel better.

Any time you feel your battery is fading, simply go in and swap it. If a recently swapped battery feels like it is not that great, swap it again...

Better Place is a good concept. Like the Volt it has a plan for short commutes and for long road trips. You charge at home for your daily commute. When you need to take a long trip, you swap batteries along the way...

But.... Getting a significant number of people to buy into the idea is a different story. It is definitely a different way of thinking. Americans are naturally resistant to change...
 
#5 ·
Swapping out batteries just spreads the degradation across multiple packs. The root problem is that the Leaf batteries are fully charged/discharged and this is known to degrade Lithium batteries. This is made more severe since the Leaf battery does not have any battery thermal management. Extreme heat is another thing that degrades Lithium batteries.

I think the issue is more confined to Nissan's desire to minimize costs by ignoring these Lithium battery facts and cutting those corners. I have not heard similar issues from Tesla owners. Thermal management is in place to minimize degradation. Of course, our Volt's do not have this issue as we have "oversized", thermally managed batteries that have been designed to maximize longivity. This is even backed up with a specific warranty.

In the case of a pure EV, I would opt for a design that takes these considerations into account, even if it costs a bit more. I think Nissan is learning this the hard way.
 
#6 ·
Swapping puts all the risk on Better Place's shoulders.

Once batteries degrade below a certain level, Better Place won't be able to put them back into service.

As to whether the Nissan has a faulty design matters less in a Better Place Scenario.... Nissan/Renault make the vehicles for Better place. If those vehicles also have a flawed design that could lead to battery degradation, Better Place will feel the impact, not the consumer.
 
#7 ·
Makes it a lot worse. The market would be completely broken. People with good batteries would avoid trading them in. People with crap batteries would be hurrying up to do the swap. The result would be that all the batteries you'd get from a battery swap would be junk. This is one of the reasons I've never thought that BP would work.
 
#8 ·
There would have to be measurable minimum standards set for replacement batteries swapped into a customer's car. Degraded batteries swapped out could be refurbished up to certified minimum standard levels and and put back into the swapping pool. Each would have individual service records that would remain with the battery over its entire service lifespan and be available for public inspection.

Car dealerships could sell the car separately from the battery at far more palatable price levels if the battery was a separate purchase item. Standardization among vehicle manufacturers would be critical for the system to work effectively. Perhaps there could be three to six different standard battery sizes covering the wide ranges of vehicle types and sizes. And there could be multiple levels of quality (and price) within each size class.

Swap stations could be situated within car dealerships, or a part of auto parts/service chain outlets.

For the owner of a BEV, the way of life would be similar to now - batteries charged at home or at remote charging locations. Battery swaps would occur infrequently, with cost depending on size class and quality level. The old battery would have trade-in value based upon its condition. Instead of trading in the entire car every two years, people might want to trade their batteries in - as I said in the leading post, car manufacturers aren't going to like this angle. :D
 
#9 ·
I guarantee you that Better Place factors into the cost model that a certain number of batteries will degrade over time and that some of the batteries coming back in will not be good enough to put back into service.

The market would "not" be broken. Better Place becomes the responsible party for policing bad batteries. When a bad battery comes in, Better Place simply recycles it.

To do anything else would be unthinkable.....
 
#12 ·
The market would "not" be broken.
Of course it would be broken. The used car market is broken for heavens sake, and this is a lot worse than a used car market. Here not only is the information asymmetric, which is the problem with the used car market, but the cost of trading in a bad battery is zero. Of course you'd be most likely to get another bad battery, which you'd immediately trade in again in the hopes of getting a better one. Rather than Better Place we could call it Better One.
 
#10 ·
The only good thing this does is transfer the risk to the company. Degradation will happen just as often, and you'll have the minimum acceptance discussion mentioned by others. Along the way, you have to keep a bunch of extra battery on hand to be able to swap them at each location. Additionally, you limit both car and battery designs , preventing either from taking full advantage of future innovations.

Suppose there's an amazing new battery out there, twice the range for half the weight - but it needs to be water cooled (or needs a steady air supply, or has to be kept at high temperatures.) If the car's interface can't handle it, you can't upgrade - and your large supply (probably twice as many as there are cars) of expensive batteries becomes obsolete and an expensive loss to the company.

If you don't choose your battery design and interface carefully, you end up locked into one shape of car (they probably can't make a minivan or station wagon out of the Better Place system because the batteries are in a tall trunk orientation from the videos I've seen.) You can't build a cheaper model with less range, or a supersports car with massive power output - neither can use you standardized battery.

As an engineer, I appreciate standards and commonality. But I've also seen far to much expense and waste that resulted from inappropriately chosen interfaces and trying to keep interfaces consistent. Sometimes you have to - but in this case, there's no market case for it.

Unless batteries get a whole lot cheaper and lighter, I'm expecting to see the EREV evolve as the major player - engines becoming more specialized until they eventually get replaced with something else, possibly fuel cells or reactors, but still basically the same idea - battery to stabilize load requirements and handle short distances, but something with more energy density to handle long distance commutes. I'd love to have Jaguar's notional grand touring with jet turbine multifuel range extenders and 800HP in individual wheel motors (C-X75.)
 
#11 ·
Unless batteries get a whole lot cheaper and lighter, I'm expecting to see the EREV evolve as the major player -
I totally agree that EREV is the way forward. BEVs never could catch on with the masses for long known reasons - short range and long recharging times - but there has always been a small contingent of EVbelievers whose commitment to the cause enables them to live and deal with the issues.

However, the believers did not seem to be ready for another issue to be exposed - battery degradation - which has shaken things up in the tight little LEAF community. Those who bought their LEAFs and are experiencing the worst of it are now having to add to the list of concerns the sobering issue of shrinking range. I wonder how many now are regretting passing up on getting a Volt in favor of a full electric.

Battery swapping would eliminate this cancer-like concern and return the believers back to concerns they've already committed themselves to overcoming.

I guess this has just been a 'what if' session for me, finding an answer to this latest concern LEAFers are dealing with. Back to reality - which for me the belief that pure BEVs are cool but are dead ends going nowhere; EREVs are what will pave the way towards EV success.
 
#14 ·
Some questioning here of the Better Place business model. Carlos Ghosn did the same in 'Revenge of the Electric Car'.

However, there may be an operational model where this battery swap system makes sense.

Recently a battery electric GM Holden Commodore modified by EV Engineering completed 1886km in 24 hours using this Better Place architecture. The Commodore is a large/full size car, the basis of the future Chev SS. EV Engineering indicate that the energy operating cost is 2c/km whereas for a petrol powered car it's about 15c/km. They like the idea of not just city travelling, but indicating that long distance trips are viable.

http://www.goauto.com.au/mellor/mellor.nsf/story2/465656E0B18EBF5DCA257A4400241285

http://media.theage.drive.com.au/cars/car-news/commodores-batterypacked-future-3467809.html

http://www.evengineering.com.au/news-media/

Buying a car without a battery, like a Renault Fluence Z.E., where the use of a battery is sold as service seems uncomfortable. I say this as I've listened closely to a presentation given in person by Shaun Agassi who made the argument seem so reasonable (no different from the commitment to buy normal fuel at a future unknown increasing price), if one can get over the paradigm hurdle.

Cost effective electric powered cars are normally not a goer for large cars - the battery is just too expensive (except for Tesla's target market for premium cars).

A potential market segment for the Better Place architecture is the taxi cab market. London has its special purpose vehicles. In Australia the taxi market is dominated by locally made large cars (one model being dominant), usually modified to use LPG which probably reduces the energy cost by 1/2 at this time (for a very small CO2 reduction). A very few hybrids are appearing (Prius, Civic, Camry). A taxi licence is worth about $0.5 million per car. Charging your taxi fare to a credit card has a 10% impost. Notably the capital cost of the car itself is small compared with other cost inputs.

Relative to the taxi licence cost (government set) and other industry costs, a BEV modified taxi using the Better Place architecture might not have an un competitive economic operating cost. The capital cost is largely in the hands of Government policy.
 
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#15 ·
I haven't seen anyone talking about a pure battery trailer - the big problems with that being how you integrate it with the car's onboard battery, and of course the poor energy density/high weight and cost of a battery trailer.

A range extending trailer has been suggested before. During the late '90s EV boom, Toyota even had someone develop one, based on a motorcycle engine:

http://www.evnut.com/rav_longranger.htm

(AC Propulsion made a number of conversion cars, and provided their technology to Tesla for the Roadster.)

There's also a Leaf owner who built his own turbine propane fed version:

http://www.mynissanleaf.com/viewtopic.php?f=10&t=6847
 
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#19 ·
I've never seen a battery swap program that I liked. There are several inherent difficulties in the concept behind a battery swap system. First some small points, before I get to the huge problem.
  • You never know the quality of the battery you end up with. Did somebody abuse that battery?
  • Who eats the cost of the batteries that no longer perform adequatly?
  • This would tend to force or at least encourage all auto-makers to use the same size battery. This would hurt innovation. We still haven't figured out what size battery the public really wants and maybe there is no set size. Different sizes for different applications. Also stifles innovation in changing chemistries that are incompatible with different cars.
  • Also stifles innovation as to the placement of the battery. Cars will be designed around the battery instead of designing the battery around the car.
OK. Now for the big issue. Lets think about the cost of a charging station. Typically costs a few thousand to install. If you managed to pull off 8 hours of usage per day, charging $1 per hour, you could pull in $2,920 in revenue per year. Or, over 10 years that would be $29,200. That would easily pay for the install, the electricity, and the charger, and there would be some good profit in there.

Now lets talk about a battery swap station. What do you need?
  • $100,000 worth of property.
  • $1,000,000 worth of equipment for swapping batteries.
  • about $100,000 worth of spare batteries on hand (probably a dozen or so)
  • $50,000 per year to deal with all of the crappy batteries people will drop off that can't be used anymore and will need replacing.
  • Probably need at least one employee. $30,000 per year?
  • Probably need regular maintenance and repair on specialized equipment.

Now that you have your swap station. Lets figure out how much the station would need to charge per swap in order to stay in business. Under current market conditions I'm going to just throw out a guess that each swap will cost more than the entire vehicle is worth. Maybe $50,000. Which means really that nobody would use the service, in which case they would go bankrupt pretty quick.

But lets say market conditions existed that they could accomplish 100 swaps per day. That would bring the costs down to, what, $1,000 per swap? Gasoline is still looking pretty good at this point.

Here's my opinion. For people who really think battery swap is the way to go, I have an alternative idea that works on a similar setup but would be much more likely to succeed financially. Swap the entire car. You drive up to a station every 100 miles or so down the highway, and there are several EV's lined up fully charged waiting for you to switch to it. I know, it sounds silly. But I think it would be more economically viable than battery swapping.