Model S | Frequently Asked Questions | Tesla Motors At ~$40k/160 miles Tesla is bringing the cost of long-range, high-power electric lower, but one wonders if the Prius Gen II NiMH battery, which has now been in the cars for ~7 years and much longer than 100k miles, is as good if not better. EDIT: I just realized that the $40k quoted on Tesla's website refers to pre-ordering deposit of their limited edition signature cars. So the car will be significantly more expensive... Which makes the question about battery longevity even more pressing. I understand that one is a stand-alone electric and the other a hybrid, but was curious to see what people's opinions are about the state of the battery development for electric car production.
I expect the prius to have about 50% of it's capacity left after 10 years. That's still enough to function normally (it only uses a 40% window) which is presumably why it's designed this way. Chevy volt is the same, uses about a 75% window, which will allow some degradation.
Tesla's price for the higher capacity batteries is $10,000 for 70 miles so the base 160 mile battery would be $22857.14. Right now I believe I can live with the range reduction. Someday I'll probably just buy a (hopefully cheaper) new battery. 1st gen Insight owners are already there as they have had to restore their packs or rebuild them with Toyota cells.
Actually, the idea is that deep cycling and fully charges degrade the battery over time. By keeping the SOC away from the extremes, the battery won't lose much if any capacity. This is what the DOE found when they tested the prius battery. After 160K mi, none of the test batteries showed any measurable degradation, so they just terminated the experiment.
Yes, because CS hybrids are not -trying- to discharge the battery. In CD mode the car is purposefully going from (say) 100% to 25%, every time you charge. That -will- effect the capacity and life of the battery.
But the model S has range of 160-300 miles. Even the lowest model with 160 miles would not drain from 100% to 25% every day. I would say about only 25% will get used daily. Weekend may have deeper discharge.
The standard way Tesla Roadsters work is to normally only use 10% to 90% charge. Keeping a buffer for long term battery health. Toyota didn't believe their batteries would last long at all. Turns out the batteries are holding up quite well, leading to Toyota's interest and investment last fall in Tesla. Slower charging also is good for the health of the batteries. I believe 20-30 amps is the sweet spot. This is with the current packs Tesla is using. It will be interesting to see what improvements they have with the new packs for the Model S.
