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Alternate Theory For Battery Swap Endgame

Ok, I'm having a hard time believing that Elon believes this battery swap thing is actually worth the time/money they're putting into this for the reasons they're giving. I'm not on board with the marketing theory, either, but I do have an alternate idea.

They know they need batteries at the SCs anyways to supplement the solar panels, right? So maybe they're trying to squeeze the most use out of them. Kind of killing 2 birds with one stone? Provide backup power for SCs and if someone wants to take one with them they can. Perhaps they're thinking: "Hey, we have to have batteries there anyways, what if we made them more versatile?" Maybe they would have opened with that, but on the other hand, maybe it wasn't ready yet.

Can someone comment on the technical/feasibility aspects of this proposal?

Sorry if this was already posted (looked and didn't see it).

I think they would have to let you know that they are using your battery to back up the superchargers, and compensate you according to some formula - perhaps how much "battery life" they used up on your battery vs. how much "battery life" you used up on your "rental" battery.

That only makes sense since they allow you to keep the swapped battery, but they intend to charge you if your battery was more "used up" than the rental battery. Clearly they are assigning a dollar value to the "used-up-edness" of a battery. If they are going to charge you to get a "younger" battery, then they should compensate you for "aging" your battery.

If they don't tell you up front, I smell a class action lawsuit in the future. I'm sure they'll do it right.

Sorry for all the quotes. I got carried away.

I have a better alternate theory. It looks like a 400-500 mile battery is going to be possible fairly soon. In addition to making some supercharging less necessary, there will be a downside in that charging a 170 kwh battery will take twice as long as an 85kwh -- about an hour. That would be too long and could eventual lead to serious backups at the supercharging stations. "BatSwap" is a reasonable alternative, especially since you might only have an 85kwh for normal driving, pick up the big battery for a long trio, and trade back for your original on the return trip.

Actually, they don't have batteries already at the SC's. As the solar arrays produce power it is either consumed by charging Model S's or it is put back into the grid at a profit. As needed, Tesla also buys power from the grid, but this is usually at night so it is at a much cheaper rate. They don't have a need or reason to store the electricity they produce, as they are actually making profit off the electricity already.

Most people don't seem to understand, that swapping the battery as being just a sort of a trip extention is merely a byproduct of the base model design.
From manufacturing and (battery) servicing standpoint it offers huge advantages. Regardless of any swapping stations becoming accepted/worthwhile or not, this core functionality has a high practical value to TM (manufactoring in the first place) and customers for e.g. when new battery capacities become available for upgrades or packs need to be replaced within warranty or to restore basic mileage per customer wishes in several years.

It's Labor Day weekend 2015. A lot of cars have been delivered.

You leave for your big vacation and get stuck in line at a supercharger -- everybody else is leaving on the road trip at the same time.

Your 5 year old kids are whining.

Battery swap or wait for hours at supercharger and get to your destination beyond midnight?

I think the main impetus for the battery swap is not the time to charge.
There is a huge market of car owners (particularly those in the upcoming Gen III market) that don't live in their own dwelling (ie they live in apartments or condos). Thus they can't easily put in their own 240v plug..... this is a long term marketing problem for TM. They need to try to get into this market.
problem solved...(or at least mitigated)

I too am a bit puzzled by the pack swap program. I think it is really cool, and I guess I welcome the choice. But I have read that it will take about $500,000 per installation. That is a lot of infrastructure investment for something that might be obsolete in 5-7 years. I would rather see them invest in a higher density of supercharger locations, and a faster roll-out of same.

That being said, we should all know better than to bet against Elon! Those who shorted Tesla stock know that all too well!

@ cb17 - no, they don't need batteries at the supercharging stations to supplement the solar panels. What gave you that idea? All supercharging stations are grid-tied, so whatever is not supplied by the solar panels is drawn from the grid. Did you actually think each supercharging station was off the grid and powered by battery power at night? LOL

@AmpedRealtor well that is the ultimate plan, to make them zombie apocalypse proof.

AmpedRealtor: if the cost of electricity varies by time of day, charging the batteries at night, over a week to run the supercharger during the weekend crush would save lots of money for Tesla. Remember, supercharging is free for Model S owners, but Tesla still needs to pay for the power. I'm pretty sure the utilities pay less for surplus power than they sell it for. That's incentive to store it yourself when possible.

Roshandosh: I don't suppose you've used a super charger on a busy weekend? Every pair of bays share the same AC -> DC rectifier stack. The result is each car gets roughly half the 90 / 120 kW advertised charging power! The extra batteries can supply extra DC power to make each bay run at full 90 / 120 kW capacity. The rectifier stacks can also be used to charge the batteries during week nights instead of idling like they do today.

TFMethane: if I'm on a road trip, I'll be burning a full 85 kWh pack every 3 hours or so. A round trip SF -> LA -> SF means placing 4-5 discharge cycles on the loaner plus time spent at the destination. It would only be fair if Tesla burns a few discharge cycles on my pack to run the supercharger. They know my GPS location and battery usage via 3G, so they can ensure my battery is not worked harder than the loaner and to top it off when I'm on my way to pick it up.

Have read the threads. Still don't get the economics. Have they shared how the batswap model take into consideration the value of a new battery versus a five year old battery? It would seem they would have to be able to assure us that the swapped battery is as strong and has same warranty as the one we had prior to the swap or it would be a bad trade for one of the parties.

@ markinfl - Here is what my gut says about all of this battery swap hooplah... At a cost of $500,000 per location, and assuming that is above and beyond the $200,000-$300,000 cost of each supercharging location, the cost of adding battery swapping to the 27 supercharging locations planned between the two coasts will come at a cost of over $13 billion. Tesla's current valuation is around $11B, I believe. So I don't see how this is every going to make it to prime time.

I think this whole battery swapping idea was hatched to create some positive press and to give us headlines about how you can recharge in less time than it takes to fill a tank of gas. Probably more impactful doing it this way than spending tens of millions on marketing to broadcast the same message. I think we are going to see a handful of battery swapping stations in California, but that's it. I believe within a year of them going live, Tesla will discontinue them citing "lack of demand" and we will never hear about it again. However, by then Tesla will have reaped the benefits of the positive marketing message.

That's just my opinion, I tend to be cynical. :)

@AmpedRealtor +1

@AmpedRealtor: I think your math is way off. At 0.5 million per pack swap, assuming 150 SC across the country, my calculator says that is 75 mil. A significant infrastructure investment, but by no means overwhelming. I don't recall the exact ultimate planned number, but I seem to recall reading something like 150. But even if twice that many, that is still just 300 mil.

That being said, I still wish they would spend the money on more SCs, with a faster roll out, as I wrote above.

I don't think the testing period of swap stations is taking away (too) much away off the SC expansion efforts in both capital and resource levels. Construction is probably done by different teams/companies anyway. Building the swap stations w/ robotics can also be sub-contracted.

OMG I'm a moron... $13.5 MILLION - not billion! I have added three zeros between my brain and my fingers. So sorry... Now that doesn't sound like much!

The other thing I hadn't considered is that most of the superchargers aren't built out yet and haven't even broken ground, so it's not like they are going to have to retrofit a lot of stations to accommodate this. The vast majority haven't even been built yet.

@AmpedRealtor - well I made a math error too; 300 pack swap stations would be 150 mil, not 300! I am actually a mathematician/physicist at a university, but my arithmetic has always been terrible; I need greek letters in the equation!! :))

@wheatcraft: is there a nice physics formula where t, e, s, l and a are combined in a meaningful way? Would be great for t-shirts. :)

@AmpedRealtor- thanks for the laughs. Still don't get how they make the fair trade work without having a large inventory of batteries (e.g., several for each vintage). Thanks

you slipped 3 decimal points. 27 x .5 million is 13.5 million, not billion. Chump change, marketing expense.

@markinfl. I'm sure battery usage in all MS are logged. Tesla can easily assign a value to each accordinly.

@cb17 The swap is just one element, and a necessary element, to complete the total package to convince all potential buyers who are still sitting on the fence that there is absolutely nothing to worry about the battery and range. No one can use that to argue againt the car after the demo. For that 10~20 million investment is totally worth it. Remember 99% of people outside this forum are not like us early adopters who are willing to take some risks and inconveniences for the best technology.

Oops, overlapping posts. Should have refreshed before typing!

Keep comparing the costs to TV ads. They're marketing, not capex, at heart. They're trying to undermine the fears of the wider public. Even if they turn out to be lightly used, they let the air out of that anxiety-balloon.

So you can get 27 swap stations or 4 30 second Superbowl ads. Hmmm.

@tobi_ger: hmmm, good idea, I will give it some thought!

My brother called me and said, "Brilliant, the man (Elon Musk) is brilliant!"

He continue to explain that most Model S customers will gladly pay to save time. The wealthy are wise too, so they will SuperCharge while dining or shopping. (Please Elon, install HPWC at SC shopping locations as needed.) The majority will prefer to battery swap if time is valuable to them.

I don't see the battery swap as a marketing gimmick. I see it as simply another argument pitted against electric vehicles getting knocked down. Elon is trying to, and succeeding in, making transport renewable via electrification. If he has to sacrifice some money to do so then he will. The same applied to SpaceX when he started it. He also, as far as I can gather, views battery swapping as an intermediate step until we get batteries with larger capacity and faster charging.
That being said, it is pointless to argue that battery swapping is a no-go because of economic reasons. There are many business models which potentially will make battery swapping work, but that is not the ultimate aim. For those who would rather that the money was instead spent on more superchargers, my question to you is: Would you say the same thing if the superchargers were not free but instead cost an amount similar to a battery swap or the equivalent range in gas? Elon made them free to encourage the shift to electric vehicles. Using the money-centric logic of many on this forum, he should not have made them free.

Like the superchargers, the battery swap is an argument for the EV only if the process is available -- not just technically feasible, but actually operational along routes people want to travel. The superchargers will be deployed fairly quickly, so they will help sales over the coming year or two. The swap machines will be deployed slowly, and only if there is "demand." I have my doubts that enough demand will develop under the current pricing scheme, but TM has time to tweak that before too many of these swap stations are built. I do hope they succeed.

I agree with the OP that the batteries at the swap stations could be used for energy storage. I imagine that there will be 2 stacks of batteries: tesla owned and private owned (swapped waiting for pickup by their owner). Clearly they can't put your battery in another car while you are on your trip, so it has to hang out and they have to recharge it - so why not use it to buffer the grid while they have it? Or perhaps the private batteries wouldn't be used to buffer only the tesla owned ones waiting on a swap customer. Regardless, doesn't this make too much sense to not be true. Elon has said they will have 0.5MWh storage (~6 85KWh packs) Sounds like they could put in as many as 10-12 and have the capacity vary based on how many are swapped out. Selling electricity back to the grid at peak rates could subsidize the station costs and reduce the need to buy energy from the grid at night.

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