"right under your nose" may means:

"right under your nose" may means:

... combining
the discussion of swappable batteries and the fact, that people say, they cannot swap it- it's to complicated within 5 miutes

and Elons hint "under Your nose".

For me, it sounds like a secondary swappable batteryback right under the nose of the Model S in the frunk.


Velo1 | 22. Mai 2013

I like this idea more than swapping out my battery for someone else's with the idea of getting my battery back on the return trip.

TM could do a secondary battery to supplement the primary battery. Owners could use/reserve these for long-distance trips, taking up space in the deep cavity in the frunk, and then when the trip is over, return the secondary battery.

This makes a lot of sense to me.

Xfrank | 22. Mai 2013

I cant believe this. How many full battery's they need in stock in one swap center?
an unbelievable extra cost en difficult to run without any people.

amirm | 22. Mai 2013

This was discussed before and makes sense. I wonder how may extra miles can be provided by a "battery" in such limited space and where they will swap them.

L8MDL | 22. Mai 2013

The weight of a battery with any meaningful capacity, placed in the frunk, would ruin handling and drastically affect the range of the primary battery. I think you're on the wrong trail.

SamO | 22. Mai 2013

I think we are more likely to see a 100-120kWh battery first introduced for swap, and then used in the X.

CaliSun | 22. Mai 2013

L8MDL has a very good point, adding hundereds of unplanned pounds at the front of the car would have a big effect on how it drove. it would also compromise its braking by putting extra load on the front brakes that wasn't planned for durring the design. Most cars have larger front brakes than rear ones to compensate for the large mass of the motor in the front and the resulting weight balance. The Tesla actually has larger ones in the rear because of its unique design.

mdemetri | 22. Mai 2013

This has been discussed in earlier threads and IMO the best answer was swappable "Aluminium–air batteries" that fit into the square hole of the frunk that is under the dashboard (i.e. "right under your nose").

Aluminium–air batteries have one of the highest energy densities of all batteries: currently ~1.3kwh/kg (projected ~2kwh/kg). At these energy densities, a 20kg battery will add ~26-40kwh for added range of ~80-125 miles (@320wh/mile) and a 30kg battery will add ~39-60kwh for added range of ~120-190 miles (@320wh/mile).

In terms of handling, adding 20-30Kg of weight under the dashboard is negligible and should not impact handling of the car.

The downside of Aluminium–air batteries is that they are not rechargeable in the traditional sense. The Al anode must be replaced. However, this is just fine if Tesla is going to 'swap' the batteries and recharge it themselves by replacing the anodes.

The only other issue in my mind is cost; I am not sure if this economically viable. However, I have little doubt that if anyone can make it happen, its Elon.

Pricee2 | 22. Mai 2013

The label on the drivers side door frame of my P85 says do not exceed 903 lbs of occupants and cargo. Five @ 150 lb = 750 lbs leaves 153 lbs for cargo and extra battery. Not much of a battery.

Whity Whiteman | 22. Mai 2013

it must be something with the trunk... it's the Cars nose, I'm shure. And it makes sense

johnpreiner | 22. Mai 2013


Your assessment makes perfect sense. This would fit Elon's "under your nose" comment, his comment about "faster than pumping gas", and the speculation that metal-air batteries are likely being developed by Tesla. We'll see.


Adam S | 22. Mai 2013

I think everyone is reading too much into the "under your nose" bit. It's just a phrase that means "plainly obvious to those who look".

Swappable batteries have been discussed ad nauseam. It still seems unlikely despite everything that's been said.

jk2014 | 22. Mai 2013

I get it now, he's talking about national mustache month in June. I think if all men (and women if they can) grow out their mustache for the month of June, Tesla will provide a 23.22% discount on the new and improved tech package activated via software upgrade.

jbunn | 22. Mai 2013

I believe in that same text he said "refill your battery" or "recharge your battery". I have no idea what he has in mind, but I don't think it's a battery swap.

hillcountryfun | 22. Mai 2013

The tweet was: "There is a way for the Tesla Model S to be recharged throughout the country faster than you could fill a gas tank."

Whity Whiteman | 22. Mai 2013

jk2014 |...very good, I'm on it

mdemetri | 22. Mai 2013

A secondary Aluminum-Air battery could "re-charge" or "re-fill" the main Li ion battery while you drive, so this idea is not in conflict with Elon's statement. You could simply put the secondary battery in the frunk, connect it up, and off you go!

It's a longshot, but.....

Mark K | 22. Mai 2013

Not simple, but theoretically possible.

The Air-based batteries are 1-2 orders of magnitude higher in gravimetric energy density, so a 150 pound pack that drops into the frunk could potentially match the cars built-in capacity.

Safety and cost are challenges.

The lower power density inherently helps limit sudden, violent discharge in an accident.

Business model engineering could address the cost. You'd effectively just rent it and swap it for recycling at waypoints.

You wouldn't use it everyday, but if you planned a road trip, it would give you new options in addition to the SuperCharger network.

Both are aimed at the current deficiency relative to gas, which is refill time.

In classic disruptor strategy, you don't simply match the competition, you far outclass them, to erase any residual doubt. (This is why there's a 4 sec 0-60 time. That kills off the performance doubt).

You could drop in such a cell in less than 3 minutes, which is 3X faster than a gas stop. Better than gas, not just equal.

If each swap cost $100, it would compare with a fill-up of premium gas. If the recycling cost more than that, they could conceivably stomach it to a degree, because few people would ever use this,.

But offering it would preempt the anxiety point. This reassurance would kill off another argument against the switch to EV''s. Even if they can only demo it now, and deliver next year, it will affect purchase behavior immediately.

Perhaps it is more than wild speculation.

One by one, Elon is systematically chopping down the barriers to change. This could help if be can pull it off.

DouglasR | 22. Mai 2013

If it is something major, like battery swapping, then the announcement will relate to a plan that TM may begin to work on now, but will become available to future purchasers, distant future purchasers.

If it is a plan that will affect existing owners in the immediate future, then it will be something not so major, an option to add (and pay for) hardware to upgrade to 4G.

DouglasR | 22. Mai 2013

Edit: "like an option"

Chuck Lusin | 22. Mai 2013

If it is under your nose, it would be your mouth! Forget the battery, it’s probably going to be better voice recognition.

akikiki | 22. Mai 2013

All, I know is I'd rather be outside driving my S than sitting here reading the forums. Can't wait.

ColonyGolfer | 22. Mai 2013

Akikiki, even tougher is the separation anxiety I have created leaving my Model S in FL while I go North for the summer having driven it for 6 months.

DTsea | 22. Mai 2013

I don't think you could mount a battery in the frunk- i doubt the big power feeders could easily be routed back to the charging electronics in the rear very easily.

d_kaufman | 22. Mai 2013

I wasn't paying particular attention to the emergency responder's video, but I think it indicated that the power is in fact routed through the frunk.

GeekEV | 22. Mai 2013

> The Air-based batteries are 1-2 orders of magnitude higher in gravimetric energy density,
> so a 150 pound pack that drops into the frunk could potentially match the cars built-in capacity.

@Mark K - Interestingly, depending on the exact weight of the pack, that would shift the Model S weight distribution from a nearly perfect 48/52 to almost perfect 50/50. Hmm. Coincidence? ;-p

Mark K | 22. Mai 2013

DTsea - you wouldn't need big feed lines. This supplemental battery concept only gradually replenishes your main pack - so it would need to carry only about 80 amps, not the hundreds that the SuperCharger and motor wiring need to carry in the rear of the car. The internal wiring would be like half a mobile charge cable.

All still speculation, but what's new and more credible now is the explicit statement in the quarterly filing that battery swap facilities are now on the plan.

The frunk pack concept may actually have merit. We'll see what happens.

Important perspective is to look at this as something you would use only infrequently, so you'd occasionally just rent it. It doesn't change your purchase config.

But if you knew that for a couple hundred bucks in rental / energy cost, you could have 500 mile or greater range for road trips, that would squelch a lot of criticism about making the switch to an all-EV stable. Remember, because this would be an add-on pack, you still have your main pack, so it would effectively double your range.

A lot of people who buy now figure they'll revert to their ICE car, or rent one if they have a long trip. But that winnows the market. If, for less than a rental car, you could rent an extra pack, another barrier would fall, and more buyers will line up. And current owners could ditch the ICE car they are keeping as backup. That saves insurance, maintenance, capital and space.

If TM could pull it off, Presto! You'd have a pure EV solution that refills faster and goes farther than gas cars. That could quickly change perceptions, and turn the market on its ear.

Mark K | 22. Mai 2013

DouglasR - If this is in fact the plan, I'd guess every car already made has provisions to accept it.

"Right under your nose".

Mark K | 22. Mai 2013

The playful, Easter Egg hunt dimension to how all of this emerges is delightful.

jbunn | 22. Mai 2013

You dont get something for nothing. If a 150 pound pack that fits in the frunk and can match the cars capacity existed, then why do I have a heavy expensive battery under my car? Come on... think about it. Makes no sense.

mdemetri | 22. Mai 2013

Because you cannot recharge an Aluminum-Air battery at your house; it requires changing the anode. See my post above for details, but the Aluminum-Air battery is practically a one time charge for the end user, but can be quickly be recharged by Tesla after a swap.

danielccc | 22. Mai 2013

It's not the battery swap. The battery is under your behind, not under your nose. Mr. Musk is too precise to mistake one for the other, or at least has been in the past.

mdemetri | 22. Mai 2013


The hypothesis is that the swapable battery goes in the square hole in the frunk (the part under the dashboard and windsheild) and therefore would be 'right under your nose'

Mark K | 22. Mai 2013

Jbunn - truth can sometimes be stranger than fiction.

Contemporary aluminum air batteries are not rechargeable, so they must be recycled through electrochemical reconditioning (ie. removed from the car).

They also have only a fraction of the instantaneous discharge current of the main LiIon pack.

Because of these limitations, they aren't viable to run the car. But what they can do is recharge it at close to the average rate you use the main pack.

This makes them suitable for this kind of hybrid, swappable add-on architecture.

Tesla is all over this hybrid concept in their patent applications.

Admittedly non-obvious, but true.

Impossible to say if this is the time that they'll be ready to spring this, but they filed the patents and they announced the swap facilities.

And Elon was pretty specific in his tweet that there is a way to recharge faster than gas.

This combination of facts makes the speculation plausible.

We'll see what actually happens.

Brian H | 23. Mai 2013

Adding a charged al-air to a car with a discharged 85 kWh LiIon doesn't exactly "recharge" the car. Starting out with a charged main pack + Al-air supplement, and swapping one or both along the way, if required and convenient ...

jeremys | 23. Mai 2013

great theory, makes a lot of sense and you don't have to deal with issues of swapping/storing owner-specific batteries. this wouldn't even necessarily have to be done at tesla centers, it could be a third-party supplier eventually (like picking up a propane canister for your bbq).

just found this. looks like Phinergy is already testing the concept.

riceuguy | 23. Mai 2013

Sarcastically, clearly the original announcement was Superchargers going to 120kw, but after reading this thread Elon decided to raise a bunch of money to expedite the long term plan to take this approach, and has been using those announcements to stall for a few weeks while making it happen! :-)

Brian H | 23. Mai 2013

Yeah, here's the scenario:
Start your road trip with a charged battery, pick up fresh Al-air extender, which "stream-feeds" the main battery as it is drawn down, keeping it in the comfort range. When extender is running down and needs reprocessing, it is pulled (and replaced, if needed).

How much would a 500-1000 mile extender for an MS cost to "rent"? It wouldn't be free, like the SuperCharger top-ups. $50-$100 per full cycle? = 10¢/mi? Don't know what it would cost TM to "refresh" them, so it's hard to guess.

Mark K | 23. Mai 2013

Brian - two scenarios:

1. You start your road trip with a fully charged main pack and put i. a fresh frunk pack. That gives you double range.

2. You use up half your combined charge and swap in a fresh frunk pack, and you're back to a full double charge.

If they manage cell potential of each pack so that the frunk pack is higher voltage than the main pack, they can deplete the frunk pack before they dip into the main pack. So if you add a new frunk pack, both are full again.

The main pack would act as a peak demand buffer, and always has to kick in on acceleration, but would recover charge from the reserve pack during cruise, when the current demand is more modest.

Even if your main pack was very low, you could drop in a fresh frunk pack and be on your way in 3 minutes. You'd only have a single charge worth, but your refuel time would be faster than gas.

If you stayed a little longer and the swap station has the new supercharger, you could get a double range fill in maybe 30 min.

Either way, this new option makes the EV beat the range and refill time of a gas car.

That would be a stunning surprise to the industry.

We'll see if these remain merely concepts, or if TM actually has this in the works.

Brian H | 23. Mai 2013

Aluminum is not necessarily the metal involved, by the way. There are other candidates. A lovely Elon+Straubel+Porritt project?

hsadler | 23. Mai 2013

Not a brilliant person, but let me understand.
I start out with my Main fully charged and I have the Frunk extender which slowly recharges my Main to give me approx 500.
Ok, so at the end of the first 500 miles I need to swap out the Frunk pack - maybe 2-5 minute process. But wait!! My Main has also been discharged and needs recharging to full capacity if I am to continue.
So what's the big advantage that I now have to pay for?

mdemetri | 23. Mai 2013


First, you would have gone an extra ~250miles without stopping. This is much better than an ICE vehicle.

Second, after 500 miles, bodily functions must be dealt with (food/drink/bathroom). This time would allow for supercharging the main pack, which at 120W would give ~150 miles in 20 min.

Third, if Mark K is correct, then Tesla could have the voltage such that that you could drop in the extra pack and as long as there is a minimum charge remaining in the main pack, you could go another 250 miles off of the secondary pack.

There are not many trips that require going more than 500 miles. It would be better than an ICE and IMO rapidly increase adoption of EV

hsadler | 23. Mai 2013

No argument it would be better than ICE. I just don't see that it is going to be a Big advantage. Especially if the SC times are reduced (hopefully)
At work, I drive a Lexus SUV which typically shows a range of 250-275 miles.
It takes about 5 minutes to fill (not counting approach, paying, and leaving) and costs over $100.
So if I can wait 20 min more and get it for FREE ( as in FREE), I would not hesitate.
Point being - the time required now is not that big of a disadvantage, if one at all.

mdemetri | 23. Mai 2013

hsadler, I agree about the time issue. However, the much bigger advanatge is psychological; it gives a extra comfort level and takes away all range anxiety. IMO, this is what would drive greater adoption.

Mark K | 23. Mai 2013

I think the idea is to attack the problem of range and refill time on multiple fronts.

The faster SuperCharger is one tool and that will satisfy most people.

An quick-change extra pack is another, and that solves two problems: Longer range without stops, and stops that are actually faster than gas.

I think the supercharger will handle the vast majority of drivers' range needs, and being free is very attractive.

But the other option provides an inarguable answer to critics who say an EV is somehow inferior to its gas counterpart.

If this option comes to pass, Tesla will be able to firmly assert that the principal knock on EV's is now gone.

They would actually outperform gas on range and refill time too.

The last barrier will be cost, and that's what the Gen 3 is aimed at fixing.

But right now, if they announce this, there would no longer be any performance-based rationale for buying a LS460, BMW 7, A8, or MB S over a Model S.

At the premium end of the market, Model S is already outperforming all of the established brands in unit sales. If they beat them on range and refill time too, the contest gets even more lopsided.

If its real, it is indeed a big deal.

These are interesting times.

ken | 23. Mai 2013

My guess is that "under your nose" will be the introduction of the European options for the US market. Parking sensors will be "right under the nose"...

amirm | 23. Mai 2013

Elon made the teae about "under the nose" and separately about recharging the model S faster than filling gas. It may indeed be 2 unrelated subjects so the introduction of sensors could be the "under your nose" item.

TI Sailor | 23. Mai 2013

+1 ksitzberg

hsadler | 23. Mai 2013

Still not convinced....

Guess it kinda sounds like "Just throw in a 5 gallon can o' gas in the back and you're good to go."

Sort of a 'cheapish' fix for a quality car.

I bought this car knowing what I had to do for what I needed to do. I have no complaints about the way things are. Easy fix is advancing the SC's capability (not absolutely necessary), but adding more equipment makes it sound like it wasn't good enough to begin with.

jbunn | 23. Mai 2013

Not convinced either. A booster battery would hold the gas equivalent of 2 gallons of fuel in a car with 100 MPG. 8 bucks.

Unless you can stock and refurbish those aluminum air batteries for a cost to consumers at LESS than 8 bucks, it's cheaper to get a gas car. Heck, it costs 8 bucks to get a 4 pack of AA batteries.

Can it be done? Possibly. Should it be done? Perhaps. Is it cost effective? Probably not.

mdemetri | 23. Mai 2013

What ICE gets 100mpg?