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Tesla battery swap: Post announcement discussion
- Thread starter dsm363
- Start date
callmesam
Member
In a Livestream video from Amsterdam a few days ago, Elon said that swap in coming. They will test demand but it will be a race between Supercharging and swap.
I really want to see this battery swap network become a standard, too. The demand for it will depend on the pricing to some extent (and on availability of course) and they will be competing against their own free superchargers. I want it to succeed though so that we won't have to say EVs take longer to "fill up" than ICEs.
I"m still of the opinion that the real place for battery swapping is for surge capacity using mobile swapping stations, either at temporary standalone locations, or to augment a permanent station as needed.
Consider summer weekend beach traffic, winter skiing, Christmas travel etc. The Supercharger network may be sized for something like 120% of normal use, but on many peak travel days, it would have to be 500% or more to really be acceptable. People traveling over the river, etc., to their proverbial grandmother's NYC condo for Christmas don't want to wait for an hour or more to access a Supercharger slot, then wait another hour to actually charge. Gas stations are often jammed on holiday weekends, and they have a lot more pumps that can refuel a car in less than a quarter of the time of a Supercharger slot. Think about what the lines at a Supercharger would be like on a holiday weekend in popular areas if Tesla is successful at volume sales.
On the other hand, battery swapping stations can handle much higher throughput than Superchargers and, since they swap pre-charged batteries, there really isn't any requirement that they even be connected to the grid, so making them mobile and temporary isn't out of the question. Batteries could be delivered and removed by truck to be charged at different locations where high powered grid connections were readily available, as opposed to locations selected for travel needs. It's a lot easier to move a few tons of batteries around than it is to put in the kind of electrical connection that would be required for a 20 station Supercharger. At some desirable locations, based on vacation travel needs, such a grid connection might well be a practical impossibility.
Another characteristic of these heavy travel weekends is that almost all trips are round trips lasting only a couple of days, a week at most. I'd think that dropping off a battery, then returning a few days later to pick it back up fully charged would be completely acceptable to most such travelers.
The actual swapping device doesn't have to be below ground. The only requirement is for the car to have enough clearance for the robot to work under it. Lifting cars so they can be worked on isn't an untried technology, so I doubt that would be much of an issue. The actual robot swapper doesn't seem like it would be a particularly large or complex device either, so making it mobile seems quite doable.
Consider summer weekend beach traffic, winter skiing, Christmas travel etc. The Supercharger network may be sized for something like 120% of normal use, but on many peak travel days, it would have to be 500% or more to really be acceptable. People traveling over the river, etc., to their proverbial grandmother's NYC condo for Christmas don't want to wait for an hour or more to access a Supercharger slot, then wait another hour to actually charge. Gas stations are often jammed on holiday weekends, and they have a lot more pumps that can refuel a car in less than a quarter of the time of a Supercharger slot. Think about what the lines at a Supercharger would be like on a holiday weekend in popular areas if Tesla is successful at volume sales.
On the other hand, battery swapping stations can handle much higher throughput than Superchargers and, since they swap pre-charged batteries, there really isn't any requirement that they even be connected to the grid, so making them mobile and temporary isn't out of the question. Batteries could be delivered and removed by truck to be charged at different locations where high powered grid connections were readily available, as opposed to locations selected for travel needs. It's a lot easier to move a few tons of batteries around than it is to put in the kind of electrical connection that would be required for a 20 station Supercharger. At some desirable locations, based on vacation travel needs, such a grid connection might well be a practical impossibility.
Another characteristic of these heavy travel weekends is that almost all trips are round trips lasting only a couple of days, a week at most. I'd think that dropping off a battery, then returning a few days later to pick it back up fully charged would be completely acceptable to most such travelers.
The actual swapping device doesn't have to be below ground. The only requirement is for the car to have enough clearance for the robot to work under it. Lifting cars so they can be worked on isn't an untried technology, so I doubt that would be much of an issue. The actual robot swapper doesn't seem like it would be a particularly large or complex device either, so making it mobile seems quite doable.
Mayhemm
Model S P85+ "Lola"
My concern with the swapping system is its complexity. There have already been multiple reports of non-functioning superchargers for one reason or another; and they are an order of magnitude simpler than a battery swapper.
How well do you think that robot swapper will function when it's buried in half-frozen dirty slush at -20 degrees? Given Tesla's spotty record with cold-weather preparation, I'm inclined to think "not well".
JRP3
Hyperactive Member
In areas where that is an issue heating elements and high pressure water jets could be a possible solution. Swappers may also be manned by an attendant who keeps them clean. Plus they'll probably have a roof.
The swapper would be covered, like a carwash, and it would spend a fair amount of time charging batteries, which generates heat. Storage would likely be underground, which has stable temperatures.
I don't see the swapping system as complex:
Bolt/unbolt like the factory, with additional care to deal with coolant
Raise/lower like any service center
Convey/move like the factory
Bolt/unbolt, raise/lower, convey/move: motions handled billions of times by electrically-powered machinery.
The only question is: How low can they make the cost of the process?
(Incidentally: my brother has been working in a warehouse, driving an electric picker which has a battery swap station.)
Nope: the real unsolvable problem is: variability of battery formats.
With battery swapping up and running, Tesla will need to make a tough decision when designing new model:
a) use same battery format as existing models and suffer performance tradeoffs (vehicle dimensions, range/capacity, weight, ...)
b) introduce new battery format and upgrade ALL swapping stations with yet another battery format
Both options are bad and very bad, depending of POV.
Battery swapping could work with a single, unchangable battery format. I don't want to live in world as limited as that.
GenIII will have physicaly smaller battery. GenIV will again be different, future roadster once more.
The whole BS is just marketing BS. Don't hold your breath.
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Of course, both problems disappear if swap stations stay limited to a few distinct locations.
It is not costly nor hard to supply a few swappers with all distinct battery formats.
But having only a few swappers is same as having no swappers for most drivers.
Swapping stations would always be manned, and even temporary ones could easily be covered, so I don't see that as a major issue, although it certainly would have to be designed for.
The battery is a box on the bottom of the car. It has bolts, hose connectors and a power connector.
1) Find bolts, hoses, power connector.
2) Disconnect.
3) Lower/Raise.
4) Move.
5) Connect.
This is all stuff that can be automated. It's robot and machine work.
As far as Tesla's plans go they will have a whopping 2 (count them) battery sizes. Given that box-shaped batteries are easily rackable, I don't see a huge conceptual problem with swapping technology.
Superswapping is an alternative to Supercharging that would be able to handle higher volume. So, there wouldn't be demand in areas of low contention, where drivers would stop and charge their or their rented battery.
The faster Tesla can make Supercharging charge, the higher volume they can support, but the current charging rate is not fast enough to support high volume. With success, they should be able to add spaces, but there would be logistical limits. So, if they can't beat the contention with fast charging, they would need Superswapping. They don't like it, they don't want it, but there's a high-sales reality they'll hopefully have to deal with.
Cottonwood
Roadster#433, Model S#S37
Tesla is planning for the future. The Distribution center going into each site is rated at 2000A, 480V, 3-Phase. Even small, 4-bay sites like Farmington and Blanding are connected to the transformer with 3, 500MCM cables per phase that give a capacity of 1290A without pulling more wire. Today's 120kW Superchargers pull 160A and the breakers in the Distribution centers are very fancy that can run at 100% of rating, Schneider Masterpack Circuit Breakers This means that even little 4-stall, 2-Supercharger sites are already configured, with a transformer change to grow by 4x to 16-stall, 8-Supercharger sites.
My personal preference would be to also focus on many more Supercharger sites. This provides geographic diversity for grid failures and makes it easier to find Superchargers on your route. With many more Supercharger sites, more stalls per site, and good Supercharger status reports in the car via the Nav or other apps, Supercharging will be robust and pretty darn fast.
Superchargers will never be as fast as Superswappers, but are a lot cheaper to install and simpler to maintain. My guess is the Superswappers sites will be limited to just a few of the busiest locations.
jeff_adams
Member
It seems to me that the main advantage Superchargers have is that they can be unmanned, their inherent disadvantage is cycle speed. Superchargers may work well for normal traffic but, once there are a significant number of Teslas, I think there's going to be serious congestion problems during heavy travel times that will make them pretty annoying, possibly infuriating. WRT cost, Superchargers don't earn revenue, battery swapping stations do, although they'd likely only would be profitable in high utilization locations and times. I think both systems have complementary roles to play.
As far as multiple batteries, I'm unconvinced that there needs to be more than 2 form factors, the present one, and possibly a future smaller one. Differences in charge capacity can be handled in the cars' firmware if it's even an issue.
As far as multiple batteries, I'm unconvinced that there needs to be more than 2 form factors, the present one, and possibly a future smaller one. Differences in charge capacity can be handled in the cars' firmware if it's even an issue.
Imagine all cars on the road are Teslas with a 60kWh battery. Let's say it's a holiday weekend in Maine with 2-lane I-95, cars 2 seconds apart. That would mean 60 Teslas reaching a Supercharger site per minute. If they need to charge for 1/2 hour, you'd have 1,800 cars charging simultaneously. If they need to charge for 5 minutes, you'd have 300 cars charging simultaneously.
I hope we need swapping.
jeff_adams
Member
Also, all early adapters with "A" batteries can swap out to the newest available battery if they desire for faster supercharging. I'm sure Solar City would be happy to get their hands on as many A batteries as owners want to swap out.
That's quite a starting premise. How about something more realistic, yet still wildly optimistic, like 1%. That divides all your numbers by 100 and seems pretty manageable.
Cottonwood
Roadster#433, Model S#S37
Even with a wildly optimistic 10% of cars, divide by 10 and you get a need for 180 simultaneous charges. Distribute that over 10 exits/sites with 24 charging stalls per site, and you have plenty of capacity and great redundancy.
I think that a good solution may be Superchargers on the highway for long distance travel and Superswappers in cities for travelers, apartment dwellers, etc. With a reasonable financial charge per swap, the urban free-loaders will be discouraged. Superswappers could also be useful for other very high usage sites.
Remember that for the typical day-to-day usage, charging at home takes about 30 seconds, 15 seconds to plug in and 15 seconds to unplug, without any additional stops. It doesn't get much more convenient than that, with any other solution!
callmesam
Member
Swap also functions well where a battery lease is offered. Since you don't own the battery, you don't care which one you get back.
$300/month all you can swap and supercharger . . .
$300/month all you can swap and supercharger . . .
Great point: batteries are not perfectly fungible commodities. Some have been abused and/or driven long miles; others, babied. The logistics become really tough if Tesla is going to loan me a pack until I can reclaim mine. Particularly if I'm planning an A->B->C route. Would Tesla give a credit, or impose a charge, based on the delta between the battery I'm dropping off vs. the battery I'm getting? That seems very challenging to implement.
But the lease route is tricky, too. 25,000 of us already own our battery; are we excluded from swapping?
This whole swapping thing seems like a real nightmare to implement commercially. I'm also not crazy about the prospect of Tesla hiring more staff, 24x7, to man these stations. Surely the company has more pressing ways to spend its capital to foster growth?
Tesla stated the intention to calculate "battery value". The computers are well aware of battery health, comparable to CAC value (given in Ah) in roadster packs.
No. If you don't pick up your battery, you pay for delta in health on top of the swapping fee.
If Tesla were shy of taking on nightmares, they weren't where they are today :wink: Besides that, I agree that not every nightmare is worth sinking money into it.
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