Top CYBRTRK model battery lifetime range speculation

mjcostel

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With the talk of the 'million mile battery' it was indicated the new battery chemistry would be good for 5000 recharge cycles and still retain 90% plus range. Wouldn't that put the the lifetime battery range at about 2.5 million miles? (5000 recharges x 500 miles = 2.5 million) This does not take into account the fact that the battery will likely not generally be charged to 100% each cycle and the slight range degradation towards the end.

Buy the truck now and your grand kids will be driving it 50 years from now.
 

Snuups

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I'll drive it further. but wait, I don't drive it all the time. I'll Need FSD. So my CT drives the night and in the morning I arrive. So I can save money für Hotels.
 

ajdelange

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With the talk of the 'million mile battery' it was indicated the new battery chemistry would be good for 5000 recharge cycles and still retain 90% plus range. Wouldn't that put the the lifetime battery range at about 2.5 million miles? (5000 recharges x 500 miles = 2.5 million)
But you don't add 500 miles each time you charge it. If you do what Elon suggests you will plug it in every night when you come home. The average American drives about 10,000 miles a year. That's 27.4 miles a day and you would pick up, therefore, 27.4 miles in each charge cycle for a total of 5000*27.4 = 136986 miles in 5000 days (13.7 years). That's pretty good!

Suppose you read the previous paragraph and feel you are being cheated and so charge every other day. In 13.7 years you will have covered 136986 miles but used only 5000 charges and thus have another 136986 miles worth of charging left on this battery. Its lifetime range is now 274000 miles. You would come up with the same range if you charge every day but drive 20,000 miles a year and so on.

This does not take into account the fact that the battery will likely not generally be charged to 100% each cycle...
If you think about such things, and as a new owner of a Tesla you will, you might decide to hold off on charging until the battery drops to around 40% and charge it to 80% thus adding 40% SoC or 200 miles per charge. Now you have your million mile battery.

...and the slight range degradation towards the end.
Most of the range degradation comes at the beginning.

In any case the million miles is very much a numbers game which depends on what set of assumptions Tesla makes about how many miles are added in a charge cycle. The other big factor to keep in mind is that your battery won't last 5000 charge cycles. It may only last 10 (infant mortality - very unlikely) or it may last 15,000 (also very unlikely). Batteries are like people; they follow mortality curves. Thus 5000 represents some statistic such as the average or median. It is a life expectancy, not a guarantee that the battery will go 5000 cycles before requiring replacement. Tesla will give you a guarantee on the battery, of course, but it will be one that the mortality curve indicates that they will not have to honor except as a low probability event.

Clearly this mortality curve is very important. Also, clearly, Telsa doen't have it because they have only a couple of trucks to test and they have only been around for couple of months. But they can still estimate the curve from laboratory tests.

Finally a person is either dead or not while a battery that only charges to 89% percent may be "dead" in the sense that its life in your car is over but it is clearly still plenty useful.

Buy the truck now and your grand kids will be driving it 50 years from now.
That's probably not true but it is quite possible that the battery from it may be sitting out in the Australian desert storing up the juice from a solar array.
[/QUOTE]
 

Sirfun

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But you don't add 500 miles each time you charge it. If you do what Elon suggests you will plug it in every night when you come home. The average American drives about 10,000 miles a year. That's 27.4 miles a day and you would pick up, therefore, 27.4 miles in each charge cycle for a total of 5000*27.4 = 136986 miles in 5000 days (13.7 years). That's pretty good!

Suppose you read the previous paragraph and feel you are being cheated and so charge every other day. In 13.7 years you will have covered 136986 miles but used only 5000 charges and thus have another 136986 miles worth of charging left on this battery. Its lifetime range is now 274000 miles. You would come up with the same range if you charge every day but drive 20,000 miles a year and so on.

If you think about such things, and as a new owner of a Tesla you will, you might decide to hold off on charging until the battery drops to around 40% and charge it to 80% thus adding 40% SoC or 200 miles per charge. Now you have your million mile battery.

Most of the range degradation comes at the beginning.

In any case the million miles is very much a numbers game which depends on what set of assumptions Tesla makes about how many miles are added in a charge cycle. The other big factor to keep in mind is that your battery won't last 5000 charge cycles. It may only last 10 (infant mortality - very unlikely) or it may last 15,000 (also very unlikely). Batteries are like people; they follow mortality curves. Thus 5000 represents some statistic such as the average or median. It is a life expectancy, not a guarantee that the battery will go 5000 cycles before requiring replacement. Tesla will give you a guarantee on the battery, of course, but it will be one that the mortality curve indicates that they will not have to honor except as a low probability event.

Clearly this mortality curve is very important. Also, clearly, Telsa doen't have it because they have only a couple of trucks to test and they have only been around for couple of months. But they can still estimate the curve from laboratory tests.

Finally a person is either dead or not while a battery that only charges to 89% percent may be "dead" in the sense that its life in your car is over but it is clearly still plenty useful.

That's probably not true but it is quite possible that the battery from it may be sitting out in the Australian desert storing up the juice from a solar array.
[/QUOTE]
I know of one grandkid driving his grandad's 65 Mustang. Stranger things have happened.
 
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