# Breaking the "Law of Batteries"



## Dr. J (Sep 1, 2017)

Tesla breaks Law of Batteries!! Overpays for electricity!!

https://www.bloomberg.com/news/arti...s-newest-promises-break-the-laws-of-batteries

Elon Musk touted ranges and charging times that don't compute with the current physics and economics of batteries.


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## KarenRei (Jul 27, 2017)

My take on the "overpaying for electricity" thing (beyond the fact that "40 cents per kWh" is utter nonsense):

https://teslamotorsclub.com/tmc/thr...s-70-kwh-battery-pricing.102783/#post-2428222


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## Reef Club (Jun 18, 2017)

My take is that Elon must have a new battery technology under wraps. Makes one think twice about paying $9,000 for LR Model 3.


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## garsh (Apr 4, 2016)

Reef Club said:


> My take is that Elon must have a new battery technology under wraps. Makes one think twice about paying $9,000 for LR Model 3.


I do wonder if that might be the case, at least from a packaging standpoint. I still find it hard to believe that they are fitting 200kWh of battery into the Roadster, when the Model 3 can barely fit 85kWh.

When it comes to price however, this is exactly the type of price reduction that the gigafactory was supposed to make possible, regardless of the chemistry. As @KarenRei points out, this is still above raw material costs, so it's still a reasonable price point.


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## roflwaffle (Sep 25, 2017)

200kWh seems reasonable to me. Stacking two packs gets them to 160+kWh, and upping the pack voltage could get them to 200kWh. Increasing the voltage wouldn't be something they could do on a production car at the moment because it really hurts the cycle life of the pack, but it's fine for the Roadster prototype.

I'm not sure where the authors have been for the past week, but Tesla's megacharger connector looks like it has one big old ground connector and 8 separate power connectors, probably for 8 separate packs, which drops their 10x current charging rates estimate down to 1.2x current charging rates. Granted, each truck would need 8 superchargers, but that's no unreasonable.

Their energy consumption figures are also far too high for an EV truck. The 220 mile truck they referenced has a 300kWh pack, which puts energy consumption at 1.36kWh/mile.

https://jalopnik.com/daimler-reveals-its-new-217-mile-electric-truck-in-tesl-1819858686

A Tesla semi at 1.5kWh/mile would need 750kWh for 500 miles of range and 450kWh at 300 miles of range, which is substantially less than their estimate. In addition, they appear to be using Tesla's projected cost for the present day Model 3 battery pack ($120/kWh), which they acknowledge will likely be substantially less by 2020, but don't include in their estimates.

@KarenRei already covered the economics of megacharger locations. The only thing I can add to that is purchasing SolarCity may allow Tesla to offset a fair amount of their energy costs in some states.

So... yeah. Apparently random people on the net who don't even work in the industry have a better idea of what Tesla's doing than analysts.


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## KarenRei (Jul 27, 2017)

roflwaffle said:


> The 220 mile truck they referenced has a 300kWh pack, which puts energy consumption at 1.36kWh/mile.


Yes, but with an 11-tonne payload  Actually sounds rather inefficient for such a small payload. Doesn't look as streamlined, though, and they may be assuming a higher speed.


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