There was an interesting article in the NYTimes from the Detroit Auto Show:http://wheels.blogs.nytimes.com/2011/01/10/the-disrobing-of-a-naked-tesl...
One of the items discussed is the ability to fast charge the car in 45 minutes.
I wonder if taking that option would more quickly deplete the battery life. Does anyone know for certain?
Probably, but it strikes me as something you wouldn't use very often. Most of the time you'd be charging more slowly at home. The 45 minute charge would only be for long road trips, which would be a pretty small percentage of the overall charges.
not for certain, I don't really know what kind of battery is in therefore it's hard to say what's the bad habbits for this kind of battery. The usual suspects are Temperature wich is handled in the Battery pack and also how much it is loaded d over a long time. Often it's not good to have your battery loaded for 100%,
So I don't really think that fast charging will affect it that much. as it only loads to 80% and the additional heat problem should be solved in the pack. But well I might oversee something...
Exactly, provided the temperature control system can handle the batteries temp during the fast charge, it shouldn't lower their lifespan.
I put up a post about the BYD e6 EV sedan coming from China in '12; it claims 50% fast charge in 10 minutes. (Total range ~185 mi.)
If you have about 1 hour and 14 minutes, you can find your answer from Professor Jeff Dahn of Dalhousie University "Why do Li-ion Batteries die? and how to improve the situation?"
It is not the charging speed because as you know, Nissan Leaf charges much slower but he mentioned at the beginning of its lack of active thermoregulation as cited in premature degradation lawsuit.
What more detrimental are:
2) Repeated Fully Charged and Fully Discharged Cycles.
As a matter of fact, Slow Charging Rate is BAD!
Watch at 22:43
Longer charging time means longer time for parasitic reactors to do its job of killing off the cell prematurely.
Tâm is spot on. I've done a lot of research into lithium ion cells. As well as some in house cycle testing in my business. The following are the bad things you can do to a cell from worst to least things you can do:
1. Full discharge. I think the Tesla BMS will shut down the car before that happens. Full discharge can destroy a cell.
2. Overheat. You will liquify the electrolyte (its normally a solid or gel. Again, Tesla's thermal management system should take care of this.
3. Overcharge. I'm sure Tesla's BMS cover this.
4. Demanding high current at low SOC.
5. Discharging to less than 10% and charging to more than 90%.
6. Storing for long period of time at 100% SOC
7. Fast discharge over 3C
8. Fast charging over 1.5C
For those not familiar with the terms:
BMS - Battery Management System
SOC - State of Charge
C rate - Charge or discharge ratio to nominal amp-hour capacity of the battery
The amp-hour capacity of the 85 kWh battery is 251.6. 1.5C would be 376.5 A. I have never seen my car charge at more than 350 amps. That was at about 5% indicated remaining charge (which is actually not 5%, because Teslas 0% is not true 0%). Also as the SOC increase, they taper the current continuously to protect the battery from overheating. Most crude BMS regulated charging systems are constant current - constant voltage. That means they start at a constant current and transition to a constant voltage. Tesla's system has a continuous taper, which, is better.
So, in short... no your not hurting the battery by supercharging.
Tâm & roger: +42 UP! Thank you both for the Ultimate Answer to the Ultimate Question of Life, the Universe, and Why Elon Musk Said, 'Don't Worry About It'.
Ohh red, no "thanks" for the bump. ;)
So Roger, does that mean that current superchargers are about as fast as you can go without minor damage to current batteries?
+1 @roger and Tâm,
Thanks for spelling it out so clearly and concisely. I hope others read this and get off of their "life-in-the-slow-lane-so-they're-holier-than-thou" attitudes that anything that is convenient must be bad.
#2 on the list was overheat. I assume this mainly is an internal battery heat, is this correct? are we talking about hundreds of degreesF, Or can parking your car in the sun on a hot day do any damage?
I wouldn't necessarily be afraid of full charge/discharge cycles. Those who regularly run their cars from 100% down to near zero on a regular basis appear to have lost the least number of miles from their estimated range on the speedo. Those of us who have babied the battery appear to have lost the most miles.
Watch KMan's video for some explanations:
Kman is active on TMC and apparently has a lot of experience with lithium ion batteries. He has also seen his range climb back up after completing several deep cycles. Prior to his battery replacement, he had run tens of thousands of miles on his first battery pack without losing a single mile, and he supercharged and went from 100% down to close to 0% several times per week.
I wouldn't have any inhibitions about supercharging, and I've started to incorporate at least one deep cycle per week to see if my range creeps back up.
I have lost zero miles on either Tesla that we've owned. As Amped points out, our pattern is at least once every week, usually twice, we must range charge and run to near zero. The car seems to like the battery being fully exercised, top to bottom, regularly.
I'm thinking that Tesla Engineers are all over the battery technology. The eight year unlimited mileage warranty is a pretty good indicator that the Tesla battery packs are well designed and very robust. So far degradation with all kinds of use seems pretty light. With repeated charge and discharge cycles one form of aging seems to the formation of unwanted chemical byproducts that coat one of the electrodes reducing surface area for charged particles to terminate there.
See Professor Jeff Dahn's presentation " How Li-ion batteries die" (https://m.youtube.com/watch?v=9qi03QawZEk). Incidentally, the PhD graduate student that helped him with the study went to work for Tesla.
Whoops! @Tam was way ahead of me. Sorry about that.