Why Tesla Model S has so many battery cells?

Why Tesla Model S has so many battery cells?

Have been a petrol head for so many years, I never think about EV, until my friend showed me The Model S last month. I want to order a Tesla Model s to go green, however I got a few questions in mind. Please help me, thanks.

1. Why does Model S has so many battery cells? 7000 is not a small number, as BYD has got only 96 cells and Nissan Leaf has got 140 cells. I understand that they use different kind of Li-ion battery, but are there any reason or benefit for that? More stable or what. Because it seems that more cells, the probability of cells go wrong would be greater. If 1 or a few of those 7000 batteries screwed up, can I still drive it?

2. Model S uses LiNiCoAlO2 as battery cathode material, which is poisonous and harmful to our environment, can it be recycled?

Thanks very much.

Timo | 2012年11月19日

1) Benefit is much lower price and higher energy density. These are very common 18650 batteries common to all kinds of mobile devices so Tesla has benefit of mass production for those and very large manufacturer to back them up. Also those batteries stacked together nice and tidy creates natural honeycomb structure which is very durable.

If one cell fails it gets separated from the rest, so no problem there.

2) Where did you find that info about cathode? I tried fast search but found nothing that specific. They are recyclable, but for what extend that is realized this far I'm not sure. Tesla is recycling them.

Nick Kordich | 2012年11月20日

@Timo - Motor Trend mentions the cells are Nickel-cobalt-aluminum (NCA):

One thing I noticed about using the small, cylindrical 18650 format cells is that there is a lot more surface area and a better shape for even cooling.

Sudre_ | 2012年11月21日

1) There is a reason the Nissan Leaf goes such a short distance on a single charge.

2) If we are going to worry about the toxicity of a battery pack then we had better pull every cell phone, laptop, florescent light bulb, gasoline product and any other product that has toxic materials. Heck I saw one weird report that if you ground up an LED light bulb and ingested it the materials would be toxic.

Brian H | 2012年11月22日

The dose makes the poison. Excess Vitamin A killed Mawson's colleagues in Antarctica (1912). Inadequate Vitamin a blinds millions every year.

jerry3 | 2012年11月23日

Batteries of all kinds are the most recycled products. This is really a non-issue even though the detractors always bring it up.

In addition, Tesla has designed the battery so that it can be reused in other applications (Solar City) once it no longer has enough capacity to be used as an automotive battery. So first it will have an eight to fifteen year life in a car and then it will have an undetermined amount of life as a stationary battery, and then it can be recycled almost 100%. How many other products get anywhere this amount of use for a single manufacturing-->usage cycle?

djp | 2012年11月26日

"Sudre_ | November 21, 2012 new
1) There is a reason the Nissan Leaf goes such a short distance on a single charge."

It's called a 24K battery

lwigley | 2012年11月30日

A big benefit of these batteries is likely multiple suppliers. Fisker had to shut down Karma due to not being able to get batteries from their supplier.

jackhub | 2012年12月2日

I think a an obvious advantage in addition to all of those listed is research. How many sources are doing research to improve batteries for mobile devices like cellphones, laptops, ipads/pods etc? How many are doing research on batteries for cars? Where can we anticipate the most improvement? I think the answer is obvious.

Timo | 2012年12月3日

@jackhub, while I agree that this is how it is now, the situation will not be that very long.

20000 * 8000 batteries is 160,000,000 batteries. One laptop contains maybe four of those so that's 40 million laptops. Considering that Model S share from sold cars is tiny compared to world wide sales, and their GenIII will sell a lot more you are closing laptop sales pretty quickly. Car batteries will soon become dominant use of rechargeable batteries.

Even now if you combine Model S future 20000 + Leaf 42700 (2012) + Volt 24000+ (2012) you are already in quite high numbers when it comes in battery kWh:s.

(BTW kinda funny to notice that Model S has half Leaf numbers even that it costs a lot more. If Tesla manages to make GenIII affordable car even close as sexy as Model S it will rule the world).

jackhub | 2012年12月4日

True, but there is an intense market pressure from the entire mobile computing industry for progress in battery performance for all mobile devices. It is both the size and performance of the battery that is of interest to that market and they are willing to pay a premium for develoopment. It is an industry that is on the front burner of both economic growth and imaginitive development. Automobiles-with the exception of Tesla ;>) are in a humdrum industry for most people.

I don't see a similar interest in the battery used by the Leaf. Other electric car manufacturers have chosen to go with few, large batteries. That form factor will not benefit the mobile device market.

I believe Tesla will ride the pressure for research on mobile device batteries in both reduced size and improved performance. Reductions in size means less weight and higher performance per unit of weight. The numbers you suggest for automobile use of batteries will only drive down the costs for the mobile market and Tesla, but not nearly as much for the Leaf and autos using the larger form factor. Simply put, that's not where the money is for R&D.

But then, only time will tell.