jdvm1988
Posts: 10
Joined: Fri Feb 28, 2020 9:04 pm
Delivery Date: 29 Feb 2020

Is there any data for DOD cycles on a battery at different % of Degradation?

Fri Feb 28, 2020 10:44 pm

Hi, first post here, I wanted to know if someone had any data or graph of the DOD cycles until end of life of battery but with different % of Degradation. I only find online data for DOD cycles of a brand new battery.

Im asking this because Im getting a 2013 S in a deal (not living in the US), the dealer cut back 6k of the price because the battery is really degradated, 5/12 bars, you read that right, 3 white ones with only 69k miles on it.

So I know I have to replace the battery and the dealer already discounted the price for it, BUT, I was thinking how much miles can it go with that kind of Degradation. I have a short commute and can charge at work, but how many miles can I "steal" from this old battery?

powersurge
Posts: 1742
Joined: Wed Oct 21, 2015 10:24 am
Delivery Date: 06 Dec 2014
Location: Long Island, NY

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 4:38 am

You need no more degradation info than that.... You have it right there.

Expect that you CANNOT drive it more than 5-10 miles...

You are buying it sight unseen? How much are you paying for it?

Expect to change the battery... First thing.

nlspace
Posts: 203
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 5:21 am

It depends upon whether the capacity bars have dropped due to overall degradation of all the cells evenly, or if there is one or more defective cells that are pulling down the pack average. You would need to read the cell voltages to determine which.

if the first case then i would guess that you could get 30 to 40 miles on a full charge at 40% capacity. if the second, then it is determined by the lowest cell.

WetEV
Posts: 3628
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 6:43 am

jdvm1988 wrote:
Fri Feb 28, 2020 10:44 pm
how many miles can I "steal" from this old battery?
Hard to know. Not much data I know of. Please keep us informed as to how your car does.

It would depend on how hot the climate is. In a cool climate it would be longer than in a hot climate. Roughly, where do you live?

About how many km or miles is your commute? At what speed? Hills?

With a short commute the major loss of capacity is calendar loss. Miles/km driven is secondary.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red
2019 eTron Blue

jdvm1988
Posts: 10
Joined: Fri Feb 28, 2020 9:04 pm
Delivery Date: 29 Feb 2020

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 7:09 am

Well I live in the DR, it is kind of hot, 70F minimum average but in the summer it can get to 90's.

My commute varies from 20 to 28 miles roundtrip, but since I can charge wherever I go it will be rare if I run more than 13 miles without a place to charge it. But half of that trip is traffic jam on a highway, it takes me 1hr or more to run those 13 miles, terrain is mostly flat so no problems there.

I know its a challenge but every mile I can squeeze out of this battery is an absolute gain.

nlspace
Posts: 203
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 7:11 am

WetEV wrote:
Sat Feb 29, 2020 6:43 am


It would depend on how hot the climate is. In a cool climate it would be longer than in a hot climate. ...

With a short commute the major loss of capacity is calendar loss. Miles/km driven is secondary.
This is exactly backwards--the battery pack will deliver more miles on a hot or warm day than on a cool or cold day. Temperature is a major factor in the rate of chemical reactions.

Where do you come up with your facts? Have you ever seen a cell datasheet for the laef cells with the test data? The answer is no, because nobody has.

The number of charge cycles is the parameter found on datasheets used to estimate cell degradation and lifetime.

jdvm1988
Posts: 10
Joined: Fri Feb 28, 2020 9:04 pm
Delivery Date: 29 Feb 2020

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 7:21 am

nlspace wrote:
Sat Feb 29, 2020 5:21 am
It depends upon whether the capacity bars have dropped due to overall degradation of all the cells evenly, or if there is one or more defective cells that are pulling down the pack average.
That is another doubt I have, one workshop here told me that I could not replace some of the cells, because they all degradate evenly, so if I were to replace the cells I needed to change all of the 192 of them. Is this true or is just a possibility more than a stone-written fact?

WetEV
Posts: 3628
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 8:04 am

nlspace wrote:
Sat Feb 29, 2020 7:11 am
WetEV wrote:
Sat Feb 29, 2020 6:43 am


It would depend on how hot the climate is. In a cool climate it would be longer than in a hot climate. ...

With a short commute the major loss of capacity is calendar loss. Miles/km driven is secondary.
This is exactly backwards--the battery pack will deliver more miles on a hot or warm day than on a cool or cold day. Temperature is a major factor in the rate of chemical reactions.

Where do you come up with your facts? Have you ever seen a cell datasheet for the laef cells with the test data? The answer is no, because nobody has.

The number of charge cycles is the parameter found on datasheets used to estimate cell degradation and lifetime.
Capacity loss is a function of temperature as well. Yes, more km can be driven on a hot day, but capacity will be lost faster in a hot climate. Capacity loss is due to chemical reactions as well.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red
2019 eTron Blue

nlspace
Posts: 203
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 8:30 am

But capacity loss wasn't the question--OP wanted to know how many miles he could drive with a 5/12 pack.

WetEV
Posts: 3628
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Is there any data for DOD cycles on a battery at different % of Degradation?

Sat Feb 29, 2020 9:24 am

nlspace wrote:
Sat Feb 29, 2020 8:30 am
But capacity loss wasn't the question--OP wanted to know how many miles he could drive with a 5/12 pack.
I agree that the OP wasn't exactly clear.

"How many more miles will this pack last for me?" is the way I read it. Not how many miles per charge. But I could be wrong, of course. Perhaps the OP will clarify.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red
2019 eTron Blue

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