ldallan
Posts: 19
Joined: Mon Jan 16, 2017 10:15 am
Delivery Date: 31 Dec 2016
Leaf Number: 000000

Objective measures for battery-friendly vs unfriendly practices?

Sat Jun 16, 2018 4:03 pm

I'm wondering if there are objective values to quantify "best battery friendly practices" contrasted to "battery unfriendly practices"?

I've seen plenty of posts mentioning "do this ... don't do that" to baby our batteries so they degrade slower, but I'm fuzzy on how much it matters. How "costly" is it to use DCFC fast charging in terms of battery degradation? How "costly" is it to charge to 100% rather than the recommended 80%?

For example for purposes of discussion, suppose our batteries with lithium-manganese-oxide with nickel oxide (LiMn2O4 with LiNiO2) chemistry would go 120,000 miles at 12,000 miles per year (10 years) with a range degradation to 60% by using "best practices" in an ideal environment:
* always use Level-2 6.6 kWh charging (220v - 240v) going from 20% to 80%
* never use DCFC (DC fast charging)
* never allow battery SOC to go under 20% (don't drain to LBW low battery warning or VLBW very low battery warning or "Turtle" or 0%)
* mild temperature like San Francisco or Ireland that don't get all that cold or that hot (mostly between 40°F to 80°F)

Contrasting to the above "best practices" to "non-optimal practices" that I've read on this and other forums:
* charging to 100%
* using DCFC fast charging
* freeway speeds in high heat like Texas or Arizona summers
* draining battery down to LBW, VLBW, or Turtle

Or perhaps using another quantifiable measure of battery longevity:
My limited understanding is that the Li-Ion chemistry used in our Leafs is rated for 300 to 500 full discharge/recharge cycles. About how many charges does it "cost" in terms of fewer lifetime recharges for using DCFC fast charging? Level-2 charging to 100%? Operating the vehicle in extreme Texas or Arizona heat at freeway speeds?

ElectricEddy
Posts: 459
Joined: Tue Feb 25, 2014 1:42 pm
Delivery Date: 31 Oct 2016
Leaf Number: 313506
Location: Nanaimo, B.C.

Re: Objective measures for battery-friendly vs unfriendly practices?

Sat Jun 16, 2018 4:33 pm

ldallan wrote:I'm wondering if there are objective values to quantify "best battery friendly practices" contrasted to "battery unfriendly practices"?

I've seen plenty of posts mentioning "do this ... don't do that" to baby our batteries so they degrade slower, but I'm fuzzy on how much it matters. How "costly" is it to use DCFC fast charging in terms of battery degradation? How "costly" is it to charge to 100% rather than the recommended 80%?

For example for purposes of discussion, suppose our batteries with lithium-manganese-oxide with nickel oxide (LiMn2O4 with LiNiO2) chemistry would go 120,000 miles at 12,000 miles per year (10 years) with a range degradation to 60% by using "best practices" in an ideal environment:
* always use Level-2 6.6 kWh charging (220v - 240v) going from 20% to 80%
* never use DCFC (DC fast charging)
* never allow battery SOC to go under 20% (don't drain to LBW low battery warning or VLBW very low battery warning or "Turtle" or 0%)
* mild temperature like San Francisco or Ireland that don't get all that cold or that hot (mostly between 40°F to 80°F)

Contrasting to the above "best practices" to "non-optimal practices" that I've read on this and other forums:
* charging to 100%
* using DCFC fast charging
* freeway speeds in high heat like Texas or Arizona summers
* draining battery down to LBW, VLBW, or Turtle

Or perhaps using another quantifiable measure of battery longevity:
My limited understanding is that the Li-Ion chemistry used in our Leafs is rated for 300 to 500 full discharge/recharge cycles. About how many charges does it "cost" in terms of fewer lifetime recharges for using DCFC fast charging? Level-2 charging to 100%? Operating the vehicle in extreme Texas or Arizona heat at freeway speeds?

I wouldn't worry too much , there are so many variables.
Low SOC is not an issue (unless you have a bad cell pair) and high SOC is fine as well just don't leave it in either of those states for any longer than you need to.
DCFC is also OK just keep an eye on the temp
24kW batteries will get hot and more so 30kW batteries particularly after several DCFC sessions ( have had mine to 126 degrees +) after the 3rd session. :(
As far as charging cycles here is one from 2013 (over 1000)
http://www.mynissanleaf.com/viewtopic.p ... 10#p266582
Another Leaf in Spain 325,000km

viewtopic.php?f=6&t=18805&start=10#p526601
Pearl White Sl
mfd date 09/16

jonathanfields4ever
Posts: 73
Joined: Sun Jan 21, 2018 6:55 pm
Delivery Date: 15 Feb 2018
Location: Kyoto

Re: Objective measures for battery-friendly vs unfriendly practices?

Sat Jun 16, 2018 4:54 pm

This is all according to a Nissan dude I spoke with when I was first looking at LEAFs so I may be misremembering parts, but the chemistry of the LEAF battery before 2018 was particularly prone to damage from heat (even Lizard packs) and high charge rate simply because they used a cheaper cathode chemistry called MnO. It was the only way to keep the price down, but it's really better suited for industrial applications.

ldallan wrote:* never use DCFC (DC fast charging)


I don't think this is a hard rule. Just be careful of charge rate and temperature. It's hard with a 24kWh pack, as you can go over 2C pretty easily depending on the speed of the charger. But with newer, bigger packs you can charge at higher Wattages without straining the cells so much. A good rule of thumb is not to go above 1C, especially on days above 30 degrees celsius or so.

That's part of why Tesla's battery packs are so great. They hit every tick box for what makes for long life. Chemistry that can handle a lot of charge cycles, a large number of small cells, large capacity to keep charge rate per cell low even if the Wattage is high, and of course the TMS. I don't know what person or team came up with their strategy or how much they're paid, but they need to be paid more.

ldallan
Posts: 19
Joined: Mon Jan 16, 2017 10:15 am
Delivery Date: 31 Dec 2016
Leaf Number: 000000

Re: Objective measures for battery-friendly vs unfriendly practices?

Sat Jun 23, 2018 1:13 pm

Thanks for the helpful replies.

I did find this article from Battery University:
How to Prolong Lithium Based Batteries

A significant factor seemed to be avoiding charging too full.

cwerdna
Posts: 7915
Joined: Fri Jun 03, 2011 4:31 pm
Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: Objective measures for battery-friendly vs unfriendly practices?

Mon Jun 25, 2018 12:14 am

jonathanfields4ever wrote:That's part of why Tesla's battery packs are so great. They hit every tick box for what makes for long life. Chemistry that can handle a lot of charge cycles, a large number of small cells, large capacity to keep charge rate per cell low even if the Wattage is high, and of course the TMS. I don't know what person or team came up with their strategy or how much they're paid, but they need to be paid more.

The chemistry Tesla's chosen also is apparently much more volatile, hence the numerous examples of pretty crazy Tesla battery fires and cells going off like firecrackers.

See viewtopic.php?p=336543#p336543 and the gm-volt post that it links to.

I'm only partway thru watching http://www.pbs.org/wgbh/nova/tech/super-battery.html that was aired last year and that I recorded on my TiVo in the past few months. They showed some examples of crazy battery venting and fires when li-ion batteries are damaged via various methods (e.g. compression, driving a nail into them, etc.) along w/some clips of YouTube from people trying such things.

'13 Leaf SV w/premium package (owned)
'13 Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

Please don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

LeftieBiker
Posts: 8895
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: Objective measures for battery-friendly vs unfriendly practices?

Mon Jun 25, 2018 3:19 am

The ending of that show is promising - finish it!
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

User avatar
davewill
Posts: 4917
Joined: Thu Mar 17, 2011 6:04 pm
Location: San Diego, CA, US

Re: Objective measures for battery-friendly vs unfriendly practices?

Mon Jun 25, 2018 10:02 am

Honestly, people have been trying to quantify this on this board for a long time, and climate seems to override mileage or any sort of charging regimen as a predictor of degradation.
2014 Rav4 EV, Blizzard Pearl White
2011 LEAF SL w/QC, Blue Ocean, returned at end of lease

jonathanfields4ever
Posts: 73
Joined: Sun Jan 21, 2018 6:55 pm
Delivery Date: 15 Feb 2018
Location: Kyoto

Re: Objective measures for battery-friendly vs unfriendly practices?

Mon Jun 25, 2018 6:02 pm

cwerdna wrote:
jonathanfields4ever wrote:That's part of why Tesla's battery packs are so great. They hit every tick box for what makes for long life. Chemistry that can handle a lot of charge cycles, a large number of small cells, large capacity to keep charge rate per cell low even if the Wattage is high, and of course the TMS. I don't know what person or team came up with their strategy or how much they're paid, but they need to be paid more.

The chemistry Tesla's chosen also is apparently much more volatile, hence the numerous examples of pretty crazy Tesla battery fires and cells going off like firecrackers.

See viewtopic.php?p=336543#p336543 and the gm-volt post that it links to.

I'm only partway thru watching http://www.pbs.org/wgbh/nova/tech/super-battery.html that was aired last year and that I recorded on my TiVo in the past few months. They showed some examples of crazy battery venting and fires when li-ion batteries are damaged via various methods (e.g. compression, driving a nail into them, etc.) along w/some clips of YouTube from people trying such things.


Yeah, that’s a bit worrisome, but it’s also hard to know how much is hype and how much is spin. The media seems to really like going after Tesla. I saw someone on another forum (Fark) crunch the numbers and they found that Teslas are only slightly more likely to be involved in a fire than ICE vehicles. Furthermore, the majority of Tesla fires were caused by an accident, whereas a majority of ICE vehicle fires were caused by component failures.

Food for thought.
Last edited by jonathanfields4ever on Mon Jun 25, 2018 10:05 pm, edited 1 time in total.

LeftieBiker
Posts: 8895
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: Objective measures for battery-friendly vs unfriendly practices?

Mon Jun 25, 2018 6:47 pm

I'd say that Teslas are less likely to be involved in a fire than a typical ICEV, but that the fires are more likely to be catastrophic. That's because of the cell chemistry, not media hype.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

jonathanfields4ever
Posts: 73
Joined: Sun Jan 21, 2018 6:55 pm
Delivery Date: 15 Feb 2018
Location: Kyoto

Re: Objective measures for battery-friendly vs unfriendly practices?

Mon Jun 25, 2018 10:14 pm

LeftieBiker wrote:I'd say that Teslas are less likely to be involved in a fire than a typical ICEV, but that the fires are more likely to be catastrophic. That's because of the cell chemistry, not media hype.


No, that’s definitely true. The batteries seem to take the whole car with them when they go. It’s definitely disconcerting. But I think it’s also pretty apparent that the media likes the attention that comes from a Tesla headline. It guarantees a bunch of clicks and flame war (no pun intended) in the comment section.

If I’m remembering that other thread properly, there are something like 400 car fires a day in America, and only 8% are from other fires spreading or from accidents. That’s a pretty interesting statistic. But questioning the safety of EVs and putting “Tesla” in your headline is a quicker and easier way to get eyeballs on your story. It’s even bigger if you piss Elon Musk off and he Tweets about you.

Return to “Range / Efficiency / Carwings”