Proof of Tesla's plan for battery swapping

[brianman]

Yeah, that's the mystery of it. From a human-interface perspective, it's odd to expect people to associate "87%" (or whatever) with "normal." If we're not supposed to set it to 100% as a matter of course, from a man-machine interface perspective they should change the scale so 100% is "normal" charge and 110% (or whatever) is "range" charge. Psychologically, it will be hard to explain to people that they should set this value to a non-round number.

For some of us there's a concept of the "capacity of the battery". Charging to "above 100%" is like your gym teacher telling you to give 110%. Even back then I was like "f you, teacher, and your bad math."

That said, I get why "full" means "100%" to some people and that a number < 100% as "full" can be confusing. In part this is why I generally avoid the term full, in favor of "standard" and "range" terminology.

 

[bollar]

The thing is there is no real "optimal" number. You can go all the way down to 40% and still see reduced degradation. 80%, 90%, etc is largely an arbitrary number. Tesla seems to have chose the cut off point based on the estimated range number rather than the actual battery impact.

From an interface perspective they can show this kind of like for an rpm gauge (where a range of rpm values are noted as "redline" using a block of color.

But what's happening is that the cutoff point is going away completely from Tesla's perspective. They don't want you to think about it. Recall Musk's announcement:

Battery Warranty

The battery pack in your car is obviously very important and expensive to replace. In developing the Model S, we took great care to ensure that the battery would protect itself, always retaining a few percent of energy. If something goes wrong, it is therefore our fault, not yours.

Except in the cases of a collision, opening of the battery pack by non-Tesla personnel or intentional abuse (lighting the pack on fire with a blowtorch is not covered!), all damage is covered by warranty, including improper maintenance or unintentionally leaving the pack at a low state of charge for years on end. The battery will be replaced at no cost by a factory reconditioned unit with an energy capacity equal to or better than the original pack before the failure occurred.

The intent is to provide complete peace of mind about owning your Model S even if you never read or followed the instructions in the manual.

I find it interesting that they mention low charge serveral times -- and never mention high charge.

I'm sure that "knowledgeable" people will charge at 80-90%, but the remainder of users won't have to think about it at all, thanks to the warranty, and won't have any ill effects. From an investor perspective, this is important to me, since it removes one barrier to adoption.

 

[djp]

I'm sure that "knowledgeable" people will charge at 80-90%, but the remainder of users won't have to think about it at all, thanks to the warranty, and won't have any ill effects.

The warranty is against battery failure, not battery degradation. If you lose capacity on your battery after a few years of keeping it at 100% that's your risk, not Tesla's.

I'm sure the new firmware will still have a warning if you set the charge above 90%, and will automatically reset it to a lower charge level after doing a 100% charge.

 

[markwj]

I think the recent "unconditional warranty" statement regarding our batteries might in fact be a precursor to the swap out plan rollout. If our batteries are guaranteed unconditionally for 8 years then who cares what battery we use. That only leaves the issue of the condition of the battery at the end of the 8th year. All Tesla has to do is state that our battery will be as good at the end of 8 years as our original and all is well. Probably have to guarantee a certain level of condition after 8 years. Kind of like the car residual value promise.

The physics of battery degradation get in the way here. No matter what, an 8 year old battery is going to have significantly reduced range than a 1 month old battery. Hard to put a figure on it, as the long-term degradation studies are just coming in now, but let's be optimistic and say 33% loss of capacity after 8 years.

So, you take your brand new Tesla, with 100% charge 250 mile range, on a road trip and stop by a battery swap station. 10 minutes later your new 100% battery is in place and shows a range of 167 miles, and that is now the battery your car keeps. How happy would you be?

I haven't seen the wording on Tesla's new 'unconditional battery warranty', but there is no way that it will say the range of the battery will be as good in 8 years as it is new. Perversely, on the 40kWh batteries, delivered as range-limited 60kWh, they might get away with that, but not with a normal full-capacity-used battery.

 

[stopcrazypp]

I find it interesting that they mention low charge serveral times -- and never mention high charge.

I'm sure that "knowledgeable" people will charge at 80-90%, but the remainder of users won't have to think about it at all, thanks to the warranty, and won't have any ill effects. From an investor perspective, this is important to me, since it removes one barrier to adoption.

They mention only low charge because the warranty is only intended to protect the user from a "bricked" battery, which will virtually never happen to a high charge battery (but can happen to a low charge battery, like it did to a couple of Roadster ones). It does not cover gradual capacity loss (you get a battery of the equal or better capacity has when the battery "failed", which implies total failure or factory defects, not gradual capacity loss). If the battery covers gradual capacity loss it'll have a hard x% in x years in which Tesla will replace your pack if it falls under that number. I doubt the updated warranty will have that.

Charging to 100% daily (rather than a lower number) accelerates your gradual capacity loss. That's just a simple battery fact. I agree most people can ignore that (the battery will still last past its 8 year warranty even if you did so), but for people who want to the most capacity left in their batteries past those 8 warrantied years, charging at 80-90% is a relatively easy way to help reach that goal.

 

[FreeOfPge]

Seems to me that you could keep yourcurrent battery in place, then use the frunk to store and swapsmaller mileage extending batteries. It is under your nose cone andseems to all of the issues...

 

[ckessel]

Seems to me that you could keep yourcurrent battery in place, then use the frunk to store and swapsmaller mileage extending batteries. It is under your nose cone andseems to all of the issues...

I've said it before in other threads, but I'll repeat it here. There is absolutely zero chance of a frunk battery or any other battery extension. It'd require redoing all the crash tests.

 

[cwerdna]

Wow, great catch - like digging up a hidden treasure on page 38 of the SEC filing. I know Israeli company Better Place, the brainchild of Shai Agassi, more here for those interested...
Our Story | Better Place

... has been pretty hot with the investment community (on and off), governments, and forward-thinking consumers for quite some time. It's got it's detractors but it's an intriguing solution that's (currently) faster than supercharging.

I've only read a few posts in this thread and I'm surprised it took so long for Better Place to be mentioned a few times. Re: the above, are you kidding?

Better Place has been going down the tubes. I wouldn't be surprised if they go bankrupt in the next year or two. See Project Better Place - Page 67 and all the posts that follow.

CA spends $3M on 6 EV Taxis clearly went down the tubes w/good $ thrown after bad given CA spends $3M on 6 EV Taxis - Page 2, Better Place closes US, Australian operations - Globes then Coda going bankrupt.

- - - Updated - - -

. Also, you do realize that Better Place is headquartered directly across the street from Tesla's headquarters in Palo Alto....coincidence?

Is that still true?

Better Place shuts down Palo Alto location, ceases U.S. operations - Silicon Valley Business Journal
Better Place To Shut Down U.S., Australian Operations - Forbes

I see no US location listed at About | Better Place.

 

[FreeOfPge]

I've said it before in other threads, but I'll repeat it here. There is absolutely zero chance of a frunk battery or any other battery extension. It'd require redoing all the crash tests.

They would have to re do safety testingfor occasionally using the frunk? Is there safety testing done forevery temporary change, for instance the occasional use of thespare donut? Or using chains in snow? Sorry if I am being naïve, itjust I do not know that much about safety testing of cars.

 

[stopcrazypp]

I've only read a few posts in this thread and I'm surprised it took so long for Better Place to be mentioned a few times.

I think most people have Better Place in the back of their minds, but the reason why I didn't mention it (and I suspect most people) is that Better Place is pretty much almost dead. As your links show, they are only "alive" in Israel and Denmark (and even there they are cutting staff). They have no presence in the US anymore.

 

[ckessel]

They would have to re do safety testingfor occasionally using the frunk?

For putting high energy, potentially explosive items connected to the power train? Uh, yeah, without a doubt.

 

[mitch672]

Better Place doesn't have to be in business for Tesla to license/adopt their swapping station technology/IP
It certainly will not be a %100 copy, Teslas pack is a different design, but a similar robot could be used.

Here are a few patents for Teslas battery pack:
Patent US8286743 - Vehicle battery pack ballistic shield - Google Patents
Patent US20130049971 - Battery Thermal Event Detection System Utilizing Battery Pack Isolation ... - Google Patents
Patent US20100136402 - Sealed battery enclosure - Google Patents
Patent US8247097 - Method of controlling battery pack humidity utilizing an active reactivation ... - Google Patents
Patent US20120183815 - Thermal Management System with Dual Mode Coolant Loops - Google Patents
Patent US20110091760 - System and Method for Inhibiting the Propagation of an Exothermic Event - Google Patents
Patent US7923144 - Tunable frangible battery pack system - Google Patents
Patent US20120037310 - Selective cure of adhesive in modular assemblies - Google Patents

Note: didn't realize they had SO many patents on the pack/pack technology...

Here is one on a metal-air battery: Patent US20120040253 - Collection, Storage and Use of Metal-Air Battery Pack Effluent - Google Patents

 

[stopcrazypp]

Better Place doesn't have to be in business for Tesla to license/adopt their swapping station technology/IP
It certainly will not be a %100 copy, Teslas pack is a different design, but a similar robot could be used.

I would rather Tesla not have to license their swapping station tech. The Tesla pack is sufficiently different that Tesla can/may have to use significantly different equipment anyways. It does depend on the development cost though (vs licensing).

Looking at the video, Better Place uses hooks to secure the battery and also has a battery connector that is directly on top of it (so it connects/disconnects simply by moving the battery up or down).
http://www.youtube.com/watch?feature=player_embedded&v=OHHvjsFm_88#!

Tesla uses bolts and I believe a wired connector (not something that is directly on top of the battery).

http://www.google.com/?tbm=pts#q=in...616,d.cGE&fp=a4dd32fe4eedb9d&biw=1024&bih=677

 

[ItsNotAboutTheMoney]

For some of us there's a concept of the "capacity of the battery". Charging to "above 100%" is like your gym teacher telling you to give 110%. Even back then I was like "f you, teacher, and your bad math."

That said, I get why "full" means "100%" to some people and that a number < 100% as "full" can be confusing. In part this is why I generally avoid the term full, in favor of "standard" and "range" terminology.

I don't see why anyone would have a problem with > 100% charge. Doesn't every car owner understand the concept of topping off?

 

[cwerdna]

I think most people have Better Place in the back of their minds, but the reason why I didn't mention it (and I suspect most people) is that Better Place is pretty much almost dead. As your links show, they are only "alive" in Israel and Denmark (and even there they are cutting staff). They have no presence in the US anymore.

Yeah. I think some people are pretty confused or unaware of the dire straits they (not surprisingly) have found themselves in.

I haven't read this thread carefully and don't intend to either, but I highly doubt Tesla will adopt anything as elaborate and capital intensive as what Better Place has tried, at least not on a widespread basis. I could envision something like this at select locations (e.g. service centers) but not much beyond it. The capital and staffing costs look insane vs. deploying more Superchargers.

 

[ohmslaw]

Doesn't the volume go to 11?

 

[stopcrazypp]

I don't see why anyone would have a problem with > 100% charge. Doesn't every car owner understand the concept of topping off?

Problem: how many percent is a "full charge". With the standard convention used by virtually everyone, it's 100%. With a > 100% charge convention, it's not immediately obvious and something that has to be learned (might even be different for every model).

I much prefer having a default "preset" than having some kind of > 100% convention.

 

[ohmslaw]

Problem: how many percent is a "full charge". With the standard convention used by virtually everyone, it's 100%. With a > 100% charge convention, it's not immediately obvious and something that has to be learned.

I much prefer having a default "preset" than having some kind of > 100% convention.

Hence the problem with switching to numbers. Either you have 100% be standard charge, thus providing important psychological feedback to guide people's daily behavior (but then you confuse people who think in terms of absolute soc), or you have to train people to charge at 87% under normal circumstances (or, even worse, do what some people are suggesting, which is think about their own usage and charge accordingly - electric cars will never take off if people have to give it that level of thought).

Hence the suggestion that by making "100" correspond to what's currently range charge, Elon is telling people go ahead and range charge every day and don't worry about it.

 

[FreeOfPge]

For putting high energy, potentially explosive items connected to the power train? Uh, yeah, without a doubt.

Okay, I can see that, but even if they have to re do crash testing, why would that stop them? Is getting additional crash testing really that cost prohibitive?

 

[cwerdna]

Okay, I can see that, but even if they have to re do crash testing, why would that stop them? Is getting additional crash testing really that cost prohibitive?

It's probably not that cheap. See 2012 Toyota RAV4 EV-Safety - YouTube, for example. All the major automakers also do tons of simulations prior to physical crash tests.