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Later this year - "A step change in Supercharging technology"

Later this year - "A step change in Supercharging technology"

So I listened to the earnings call yesterday and Elon made some interesting comments about Supercharging, including the fact that they are going to have a fairly large announcement around "a step change in Supercharging technology." Just before he made this comment he also stated that they were working on improving the speed at which cars get charged. He then said that the original reason they reached out to the New York Times was around the announcement that will now come later in the year.

I am guessing that they will find a way to dramatically reduce the time it takes for the car to charge on a Supercharger.

So what's your guess for what the announcement will be?

P.S. - For those of you interested, Elon talks about the Supercharger network around minute 31 of the earnings call.

P.S.S. - I bought the stock today based on the earnings call and the 10% drop in the price

Mark K | February 23, 2013

Vgrinspun - some other data points here.

My take as to why they limit their promises to the 8 year warranty is this:

Robust engineering is about lots of margin. So you under-promise and over-deliver.

If you can do X under good conditions, then you rate it at 0.5X so there is buffer for unforeseen hits, while still delivering good performance.

I have talked with Elon, JB, and other TM engineers, and these guys are honest to a fault, and sincerely on a mission to do this right. The numbers disussed as intrinsic to the battery are in the 10 - 20 year range, but it is so highly dependent on individual environmental and usage conditions that it would be irresponsible to set that expectation.

I don't think TM is hiding anything. They just want folks to expect safe, rather best case numbers.

Example - I get great battery life out of my iPhone. But here's a how thermal event affected that: one day my black glass iPhone unfortunately sat on my dash for an hour while the car was locked and in full sun. When I got back to it, it was so hot I could not hold it. I knew this was trouble. The silicon would be fine, but the Lithium Polymer cell in it would be compromised. Sure enough, it would no longer hold a charge and had to be replaced.

So when Apple quotes battery life they have to make some assumptions about how you will use it, and leave some margin. Unless you abuse it, it works great.

So if you want to baby your pack so it lasts longer than spec then do this:

1. Leave it plugged in when not in use. This lets the active thermal management run whenever it's needed.

2. Stay between 80 and 20 % charge. Extreme discharge or max charge has a cumulative effect on the chemistry and strucure (grows dendrites) and shortens life.

So don't leave your black car parked in the Arizona sun for a month with a discharged battery. (Duh!).

I you take good care of it, your pack will last longer than promised.

Mark K | February 23, 2013

BOT - this thread is about Superchargers -

What do you guys think qualifies for a step change (big leap)?

I think getting a 50% refill in 10-15 minutes would make a huge difference. It'd feel more like gas stop.

I also think pushing the fill level cutoff for fast charging to say 70% would make a big difference. if TM can tease that out of the thermal and charge management system, that would be awesome.

Speed would multiply the user capacity, and fill level is like virtually upping the density of SC locations. Basically, you could go farther and faster with the stations they already have.

Of course, more stations is more convenient in all cases.

It took a decades to build the gasoline infrastructure. This change will blow that away. In 36 months, I think we will be "shocked" at how quickly things are changing.

jkirkebo | February 23, 2013

jat: I've seen 46kW charge rates on the Leaf, that is very close to 2C. However the current ramps down at 50-60% SOC depending on temperature.

And there is no active air cooling for the Leafs battery. It is entirely passive.

vgrinshpun | February 23, 2013

I think this would be a game changer. The thing that concerns me, though, is cost if this would require adding 800kWh worth of batteries to every SC station. If one assumes $300 per kWh installed cost for the battery, that would add up to $240,000 per SC station or $24 MM per 100 SC stations.

Brian H | February 23, 2013

vgrinshpun;
It's early days for this yet, but "used" batteries could be had for lots less and stacked as deep as needed to accommodate their reduced (70%?) capacity. Some analog of the thermal management system in the MS would likely be needed, of course.
IAC;
Mark K, jat, vgrinshpun +1,+1,+1
Thanks for the very informed commentary.

Net, net I stick with my projection that charging times will be halved, which as noted above at least doubles the throughput capacity of the S/C network. Not that I ever accepted that this was going to be a serious problem.

Mark K | February 23, 2013

Vgrinshpun - Hopefully they can manage capital costs by phased introductions in high traffic areas first.

Also, fractional installs (with modules less than 800kH) may be just fine in lower traffic areas.

800kWh can handle 10-20 50% (85 / 60) charges in a burst with no recovery time. That sounds pretty good for a busier hub, but is probably overkill for less popular sites in the early days.

Long term, they'll probably need more than a megawatt-hour once EVs get popular.

In any case, I think they contemplate a scalable architecture, and they will have plenty of statistical data on their servers to find the sweet spot.

Andre-nl | February 23, 2013

jat, jkirkebo, the LEAF battery has a different chemistry.

They are all called 'Lithium Ion', but in fact there is a widely differing palet of all kinds of batteries with varying properties (charge/discharge rates, energy density, tolerance to high/low temperatures, cycle life, calendar life, cost, etc.). The comparison with the LEAF battery is therefore not very meaningful.

Andre-nl | February 23, 2013

As an addition, the specs for the Panasonic NCR18650 used in the model S state a maximum charge charge rate of 0.7 C: http://industrial.panasonic.com/www-data/pdf/ACA4000/ACA4000PE4.pdf

It would seem the current SuperChargers already exceed the official Panasonic specs, even more so when they put on a 'turbo'.

Robert22 | February 23, 2013

I haven't seen any commentary on the capacitance breakthrough Elon mentioned in either an article or interview. Could the SC announcement be related to this breakthrough?

July10Models | February 23, 2013

@Andre-nl
That .7C charge rate is without cooling. The cooling system in the MS allows for quicker charging.

jkirkebo | February 23, 2013

The Leaf battery does however support more or less the exact same discharge rate as the Model S P85.

Leaf: 90kW/24kWh=3,75C
P85: 320kW/85kWh=3.76C

(P85:310kW motor + 10kW accessories (same as Leaf))

So with the same discharge rate, it's not a stretch to believe they could support the same charge rate too ?

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