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Why use Superchargers? Just change the batteries.

Think about it. I talked with Jason at Tesla and he said it faster to change the batteries (with proper equipment, lift, etc.) than a gas tank in a ICE. What if instead of supercharging stations you had a network of stations with batteries already charged and waiting for you to pull into a station, much like a car wash, that pulled off the old battery and replaced it with a new one, in less than a few minutes.

If you ever had an electric RC car, you know it takes 15 minutes to charge the batteries and 5 seconds to change it. I realize infrastructure would have to be put into place for this system, and a different business model, but the station could take your depleted battery and replace it with a full charged one, then charge the depleted one and once fully charged put it into another Tesla. The Tesla car itself would be 30k cheaper as you would only rent the batteries for a monthly fee and they would get properly recycled once the batteries were no longer useful.

It would work more like a battery rental than owning your battery. You would pay a fee for the use of the networked battery stations and have close to instant fill-ups. You could also simply charge overnight as normal if u desired.

I believe with the proper design, a lift system could auto replace batteries at each station very quickly. Something to think about for the future.

just and idea from a guy thinking about buying a Model X when it comes out.

In the Model S, I believe the battery is an integral structural component. I don't know how easy it would be to make that piece removal because of structure reasons. Also, a Tesla battery is way more complicated than an RC car battery. It probably has hundreds if not thousands of wires coming into it for the battery management system, and hookups for the liquid colling system. Factor in cost of labor and the whole thing seems quite complicated and expensive. Also, several years out, battery technology will improve making the whole thing moot.

Better Place -- Google it. The most recent hits you get will be its decision to close up operations in North America. There's a reason. Actually, numerous reasons. As Elon said, "the business model doesn't exist to make it work yet".

Tesla battery is designed for fast swapping, however battery swapping infrastructure is not economically viable (too high maintenance costs for too few customers).

I visited Better Place in Israel and learned its business model. Executives at Better Place told me that they all look up Tesla and believe Tesla is the true leader in EV in the world. Better Place model (exchange battery through battery swapping station) works OK with a small country like Israel, but does not work in a country with vast land like US. Better Place model works like mobile phone carrier plan. You buy a car specially designed by a third party car manufacturer. Better Place builds battery exchange facilities across the country and uses its system to monitor the usage of your battery in your car and tells you when you need to exchange a new battery. You pay with the mileage use under either the annual estimated mileage plan or actual mileage (similar to your different phone usage payment plans). Thus, Better Place is not an EV company but an EV battery exchange facility provider and EV battery usage management company.

Even for an 85 kWh battery, that's a whole lotta swappin'. 5-10 X per month. For a smaller battery, 20-40 kWh, it would be 12-25X per month. That is NOT easier than home charging! And it would cost at least 10X more.

I bought an electric car to get rid of having to stop somewhere and fill up. I drive only where I want to go and then back home without stopping. The S 'fills up' while I sleep, eager to do it all over again. Seriously, does it get any better?

This has been discussed ad nauseum. There are apparently a lot of people who think the swapping idea is better than what Tesla went with. My advice to them would be to start your own company and implement battery swapping if you think it's a good idea.

Battery swapping requires as many swap stations as superchargers, and they are far more expensive and you have to have an inventory of batteries as well. Personally, I think a battery rental situation could work -- you buy a 40kWh car, and then in major cities there is a Tesla battery rental center and you go swap your battery and take an 85kWh battery on the road trip. Then you use superchargers and other charging infrastructure on that trip. Compared to the Better Place model, you only need relatively few swap stations, much fewer batteries, and because this is for long-range travel you are willing to schedule it ahead of time (ie, reserve a battery from x-y) so they can plan much better about how many batteries they need where. It also isn't the everyday driving, so you are likely willing to pay much more for it, probably up to what you would rent an entire car for (after all, you did save $20k on your car up front and you get the benefit of cheap electric miles for your every-day travel).

That said, this is still a lot of capital and selling more 85kWh cars probably helps Tesla right now. However, since the Model S was designed to have the battery swapped in about a minute, it could be done in the future if there was demand for it.

this sounds exactly like the Renault system which is planned in France ^^

@uldry2000 - are you talking about the Renault system used in the Fluence with Better Place with 100km range and battery swapping, that they have quietly dropped from future EVs like the Zoe which use fast-charging instead?

Or is there something else I'm not aware of?

I think the demand is mostly imaginary. People who say they would swap would find the cost and complications excessive. And you can't be partly pregnant; the batteries would have to be rentals, which is a permanent choice, and changes the entire car ownership model. It will never happen.

Thanks for all the comments. I was unaware of this batt rent model was already being used in other countries or I would have mentioned it. This idea not only has appeal for long travel, but also lower initial cost of the car as you throw out the cost of a 20-35k battery. Let some huge battery rental company manage the depreciating asset of owning a battery (for profit) instead of forcing the little guy to bear the brunt of the cost. This would get more mainstream car drivers accepting EV I think.

I think its great I can charge up at my home at night, but for long trips I think its a drag to be forced to wait, even for just 30-60 minutes every x miles. I personally don't want to be taking more than 1 30-60 minute break on long drives across country, because frankly it takes too long and my time is valuable. I wouldn't mind one stop of this length, but not two or three.

Also, the idea of renting space on a depreciating asset (battery) appeals to me more than owning something that not only degrades over time but also gets cheaper as tech improves. Its appealing to the consumer because you can own your car, only the fuel capacity is leased and this is hidden in the car, so the cars can stay personalized, unlike the "leasing a car" situation where miles you drive are also limited.

I would rather pay some monthly fee for the right to have a rented batt in my car, even if I only swap it out once a year for the annual road trip. 99% of the time it would sit in my car charging each night. I would of course make the trip to upgrade to the latest and greatest batteries as they are introduced into the network, (perfect timing for and upgrade is on the infrequent road trips). That way I am always getting the latest battery tech available with the greatest range.

I am taking only a 2-5 minute stop to swap out a battery (similar to an ICE stop to fill up) that is fully charged, and the car would cost about 30-35k less in up front costs since we don't have to buy the batt and I wont have to stress over what to buy, a 80 or a 40 etc. Planning for a battery size is a pain. Besides you don't know your future needs. Someone could buy a 40 and realize then need more and be stuck. It also limits job opps and general life flexibility because you might not be able to travel to a new job location with the EV that was perfect for the old job situation, or maybe your wife gets a new job, or you get married and living situation changes, or you could buy the 85 and realize you only needed a 60 or 40 and wasted 10-20k.

I would rather just join a BattCo Network Rental Company (and this doesn't even have to be owned by Tesla) where all the batts are the latest tech with greatest range all for a monthly fee, and not worry about my batt limitations. As 115kWh+ batts with the 400 mile range get released they would be introduced into the network faster than I could afford to buy replace them myself so I always have access to the latest tech as its released each year at the lowest initial price. In 8-12 years we might have 170kWh batts available. I don't want to drop X amount of dollars to replace my old worn down batts, I'd rather just get the batt in the network and continue paying the monthly fee.

I just thought it was a neat idea. To all you saying go start my own company, don't be so thin skinned about defending Tesla's model. I still love the company and respect what they are doing, but for me, until the range increases, I will only use a Tesla for home base driving which is 90%+ of the driving my wife and I will do anyway. The ICE will remain the road warrior for trips, but that is only 1-5% of the driving so its still a huge improvement for us. Model S is a huge leap forward for EV, but imo, even with the 85kWh its too inconvenient, unproven to take these on long road trips (especially if you have run into weather detours). I know some guys like to spend hours working out sufficient algorithms to calculate range along with their hard won experience, but that is just unrealistic for the masses to latch on to this.

Besides, I'd rather knock $20k off the base price (40kWh batt at $500/kWh) of the Model S and pay $32.5k for the base model, then sign up for a batt rental program for a $1000 signup fee and $250-$350/mo rental. Let the batt company use economy of scale and their management prowess to get the costs down and make a 5-10% profit margin.

The barriers to entry on the Model S would then be lowered so many more people could buy one and they never have to worry about batteries, the just drive the best available. Then they have to worry about battery size so they have even less maintenance and don't have anxiety of replacing an expensive batt every 8-12 years.

I can afford the Model S, but many people I tell about it can't and I was just trying to figure out a way for the masses to get involved earlier. People are used to paying $300-$500/mo in gas prices anyway so paying a rental fee of something in that range would be no different than owning a gas car, and they would still enjoy the benefits of EV. But not everybody can throw down 80-90k on a car that comes with travel compromises. A lot would be lining up to pay 33.5k with a $350/mo battery rental cost.

Your description of the economics of the battery company are very sketchy, and are what Elon was referring to when he said there wasn't yet a business model that worked.

If there were, in a couple of years, 50K US Model S & X owners (probable), the in-use US-only battery inventory would be on the order of $1 bn, with at least that in stock inventory, probably double. So $3 bn inventory, and say 400 robotized shops to swap them out set up in or near cities for at least a few $million each, is another billion or two. So operation facilities worth $4 bn+, before admin, staffing, training, servicing. To handle 2 yrs. of Tesla sales!

All of that to be carried by rentals, with turnover and upgrades as/if new tech arrives on the scene? Better Place couldn't make it fly in tiny Israel and Denmark. With purpose-build Renault city cars.

So while you can make it sound attractive from the user/customer POV, it's a much steeper hill to climb for the supplier. (Note that the very safe TM batteries are likely the only ones likely worth using, otherwise the system's liability costs would be intolerable. And if it appealed to as many as you suggest, you can double or quadruple the above numbers.

typo: ... above numbers.)

typo 2: ... purpose-built Renault city cars.

Wow, this guy already figured out my idea, well I guess it wasn't mine after all since this guy already thought this through. He even used the same car wash analogy!

He's a pretty smart guy I hear.

http://www.youtube.com/watch?v=FcoJt2KLC9k

A battery swap in a Model S might well take as long "or longer" to accomplish than supercharging There are already wait lines at some supercharger locations at times. The battery itself may be plug and play but, the cooling system etc. are probably not so much. Besides, supercharging is "free". So why would I want to pay for a swap that in all likelyhood won't be any faster? Why would you want to snatch defeat from the jaws of victory

@Superliner - Elon has previously said that the Model S battery was designed to be swappable in a minute or so.

@mattmorget - you will note that Shai Agassi is no longer the CEO of Better Place, as he was kicked out last year. The company has been bleeding money, has few customers (~600 at the end of 2012) in a country where they have a government-granted monopoly on EVs, Renault removed battery swap capability from the Zoe and replaced it with fast-charge capability, etc. The problem is that for the economics to work out for the company with the huge capital outlay required, they have to charge the customers a lot. Customers don't like paying a battery lease fee higher than they would ever spend on gas, so unsurprisingly they find it hard to get customers and cancelled their network in Australia and the plans in the US.

I think it is much better to be in Tesla's position than in Better Place's. If you think there is a great market here, I'm sure someone with a business plan and financial backing could get Tesla to sell them a bunch of batteries and work on the automated swapping design.

@jat +1
what you said.

@ jat@jaet.org & Brian H

Perhaps the battery IS capable of being replaced quickly but a minute? not likely It would take longer than that to get the car into a service bay properly secure or hoist it or the battery down and lift another into place, make the needed electrical connections replace any lost coolant?? Post replacement performance checks for function etc. Remember it's "total wait time" to the customer not just the time to replace the battery itself once the car is in the techs. possession whence he/she can commence the swap.

But just for grins lets say the battery itself can be changed in 10 min. That does not take into account others who may be there ahead of you, wading through a line of customers to get to a sales / rental rep. to pay (unless you propose the batteries and associated labor costs should be provided free "like the supercharger"?) for the swap or in some way identify yourself etc. How about weather? Ever driven in slushy snow? you know the kind, that clings to everything on the underside and packs the wheel wells of your car in a frozen state in >32F air temperatures.

A host of jiffy lube like techs perhaps driving, pawing your car? to drive it into a stall or? where this swap will take place? Bolts or retaining fasteners not properly torqued (remember the battery IS a stressed member) and integral part of the cars structure when installed, subsequent squeaks rattles for less than stellar installations. Cost of deployment (physical footprint) to warehouse batteries, support an area large enough for trucks to get in / out to replace spent batteries in inventory that fall below spec.

All this while I simply drive up plug into the supercharger go inside where it is nice and warm "or cool" enjoy a hot / cool beverage and watch the proverbial monkey eff-ing the football at the battery swap station. Come out, and drive away knowing my car has not been molested.

I have some expertise in fleet maintenance and automotive repair and nationwide infrastructure for battery swapping would be a HEAVY LIFT at minimum and economically cannot match the supercharger concept "at present" and doubtless for the foreseeable future.

Many seem to oversimplify the logistics behind this making it seem like swapping batteries in a flashlight or something.

To add to above You'd have to charge all those spent batteries at a fairly high rate or have more inventory, do you do that from the grid? solar? then you would need even more space for the array.

For the amount of electricity you'd have to have flowing into that facility, and the footprint you would need, you could potentially have a whole parking lot of supercharger connections.

Think about it? REALLY! I think Elon got it right the first time.

Building stations capable of swapping batteries, whether it's a magical robot or real people, would be more expensive than the superchargers, and all this for something that, at least for several years, won't really be used (or at least it won't be necessary) that often.

People are using the superchargers today, but I bet most people right now would get by just fine even without them if they weren't available. At least the superchargers are a sort of easy to build, low maintenance solution. Battery swapping stations (and the whole logistical system needed) I think would be very expensive, yet under utilized.

@Superliner - I can't find it now, but early last year Elon made the statement that the Model S was designed to have the battery swapped in a minute. He also said there were no plans to do a battery swap system because of the economics involved, and nobody ever pressed him on the timing, but I am confident he wouldn't have said that if it wasn't faster than what Better Place was already doing.

Notice also I was not advocating for a battery swap solution. If it were viable at all (which I am not convinced of, see Better Place's failure), I think it would have to be only for long-distance travel where you could reserve them ahead of time and plan better to reduce the overcapacity, as well as only needing one battery swap center per major city.

Thanks for the comments. I do feel that there would be hurdles with battery swapping, but I also feel that there will be hurdles with quick charging that are not seen yet.

Think about it. A charging station with 4 spots can only serve about 8 cars per hour, and this is not fully charging them, so those that need a full charge would require 60 minutes. On a 3 day weekend when everyone is travelling and on their way back from a destination and only 3000 model S are out there it might work, but in a few years when 20-50k cars are out there, or millions in 10 years, how many charging stations will be required to handle the throughput of traffic required on 101 or I5? If you ever travelled on July 4th or Memorial day weekend you know you may have to wait even at an ICE gas station depending on what time of day you travel.

Pardon my hubris, but a lift would not be required if an underground robot could swap the car battery in less than 2 minutes. A system such as this would be able to turn out 30 cars per station per hour. You just drive up, it detects the vin on your car to make sure you are part of the network (with wifi) and swaps the battery. No human interaction is required much like an auto car wash. A 4 station setup could handle 120 cars per hour, rivaling an ICE gas station throughput. To match that kind of throughput at a Tesla Supercharging station, you would need 60 charging stations and each customer would be waiting 15 to 30 times as long.

I am just saying the current model does not scale well especially if stall space sqft is a limitation. Elon often says he wants to build something better in all aspects, but one category where the car fails to match an ICE is in filling up or re-charging speed. If he actually had a system in place where you could "fill up" in 2 minutes or less without getting out of your car (and may be even include a car wash) then you really would have the ICE beat.

Yes infrastructure would be required, but the high speed train that CA plans would cost a lot more in infrastructure costs than having a charged batteries swap infrastructure in place every 50-60 miles along 101 freeway or I5, even if it was government funded and not privately owned. I'd rather see that than a high speed train from Sac to LA, costing billions more in tax dollars with less utility.

http://en.wikipedia.org/wiki/California_High-Speed_Rail

For example, Phase I of the high speed rail is $69.7 billion (2013) and runs some 400 miles from San Francisco-to-Anaheim along I5. If we assume the cost of a 85kWh battery is $35k and a simple robot swappable stall is about $2.5 Million per stall, $10MM per station (I believe it would be less) and we assume that its technically feasible to manufacture electric cars that are hot swappable (as Elon has said) for little to no additional cost (its the infrastructure that is expensive) then I believe the CA tax money would be better spent on battery swapping infrastructure than a 70B super choo-choo train.

We could have 8 stations spaced 50 miles apart for phase 1, each housing 100 85kWh batteries.

Costs per 4 stall station:
Capex (stalls, robots, etc.) $10MM
120 85kWh batteries on hand per station, 30 batteries per stall $4.2MM
I came up with this number because we know 85kWh batteries can be fully charged in 1 hour, and we estimate that every 2 minutes a battery will be swapped if 100% capacity is utilized so that means each stall must have 30 batteries on hand to function and charge at full capacity. Let's add $800,000 for a year of payroll service to make sure everything is running properly, 4 techs at roughly 200k ea.

So that would mean the first year costs would be about $15 million dollars per station. 8 stations with 4 stalls each and 120 batteries in hot swappable inventory spread 50 miles apart from San Francisco to Anaheim would cost $120 million dollars the first year to operate. This seems like a much better bargain than almost 70 billion dollars for the choo choo train. This would cost us about .17% or 1/583 of the cost of the super train and could be built much quicker. The interest on borrowing the $70B dollars it would take to build out the train would be 23 times less than the interest of the entire cost of the system. 4% interest on 70B is $2.8B. After 8 years, Newer better capacity batteries will be rotated in to replace the older 85kWh ones. If you wanted these stations every 25 miles it would costs about $240M. In fact, for less than %1B you could have these stations every 12.5 miles apart which would add convenience factor and still cost more than 70 times less than the super train.

You guys that say it can't be done cheap, well in regards to a single company like Tesla, yes that is too costly ... but in terms of a government program its peanuts. A company with substantial means like GE could also put this program into place, for profit. I mean you don't think you will ride that 70B train for free do you? The riders will still have to pay a hefty sum.

Back to Tesla ... I am concerned about already seeing all 4 charging stations filled in pictures with so few cars on the road. I hope Tesla continues to not only roll out more stations, but expand each station as this is just as important. It will be a huge turnoff to have to wait 1-2 hours for an open stall, then wait another 30 minutes to charge the car.

Overall this is a small problem as 95% of driving is within 50 miles of your home, but it still means a two car family is better served with one EV and a ICE for long distance travel, or a one car will possibly have to rent an ICE for the trip.

We know it technically possible to do the battery swap idea, so instead of saying the battery swap idea is too expensive, I'd like to think that its more expensive NOT to do it and use alternative means like super trains. In the grand scheme of public work projects, $120MM is not very much infrastructure.

I don't think Tesla has the means to do this, and I think the strategy they are using with supercharges is better than nothing, but I think if we plan this out from a broader scope its really not as expensive as one might think.

I don't see where high-speed trains are an alternative for battery swap stations.

For comparison with charging, you are ignoring the number of batteries that would be required to have that sort of throughput, where you store the batteries, how you charge those batteries, and how you deal with different battery conditions when people own their own batteries.

If you really believe this is a golden business opportunity, then by all means write up a business plan and go talk to financiers. Prepare to explain why you can succeed where Better Place is failing with a government-mandated monopoly though.

@Matt
Using your figures 120 85kWh to be recharged in an hour. I calculate that to be over 10MW of power.

Contact your local utility and tell them that you have a new business opportunity that requires a 10 Mega Watt power supply. Ask them how much it will cost to have that installed, then how the monthly bill will be 2000 mega watts usage.

Are you Indicating Tesla will not be able to expand to 120 stations in the future?

@jat

I draw a comparison with the $70B train project and the $.12B EV battery network weighing their zero emission travel utility against their cost.

"For comparison with charging, you are ignoring the number of batteries that would be required to have that sort of throughput"

I indicated 120 batteries per station at a cost of about $4.2MM per station. Any sqft requirements to store batteries are going to be much less than parking space for 120 Teslas. Equally charging 120 batteries will be no different than charging 120 Teslas, although the throughput woul be slower with just charging stations because u start from a depleted battery while the batteries housed at the station would be charged full overnight.

I don't plan to start a business from this, more just exploring the feasibility of quicker charging.

@ghillair

Ok you are introducing a limitation in power throughput. Ok whatever limitation you place on charging batteries you place on charging Tesla supercharging stations, So let's assume 10 in the limit. Well I contend if you have 120 batteries (or whatever amount is most efficient to have on hand for the throughput of traffic) It will still turn around cars much faster than no batteries.

10 are always charging to full capacity at all times (even when all 10 stalls are not filled with cars), always getting ready for the next group of travelers.

Any power limitation you place on charging batteries will equally be placed on charging cars that stop in to charge. The key difference is batteries can be charged and readied during off peak times so the capacity is a direct function to the batteries on hand + 10, while charging stations alone can only throughput 10 cars at peak.

There won't be 120 cars parked at a charger at once, so if you need 120 batteries per station then you will need far fewer parking spaces.

There is clearly very little point in using a battery swap station, which much higher capital cost, if you are going to charge the batteries as fast as you would supercharge cars. So, you are instead charging them slower but using more batteries to cover the load.

But really, I don't see much point in continuing this conversation -- you haven't given any reason why you think this will work out better than Better Place, who has a government-mandated monopoly on EVs in Israel, which is a very small and particularly narrow country so relatively few battery swap stations. Until you do so, this is an exercise in futility, as it isn't clear that you can have any system which is better for both the consumer and company, which is necessary for any commercial solution to exist.

Comparing it to a hypothetical high speed train makes no sense, as that doesn't count the fact that everybody would have to buy an expensive car to be able to use it, which is exactly the opposite demographic of most mass transit.


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