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[DerKrawallkeks]

Don't store it full or empty in a hot environment, as this accelerates degradation.

What is your source for accelerated degradation when empty?
From all I know, this is wrong.

[DerKrawallkeks]

Loose rule of thumb is that with 0-100% charge cycles (no pauses) you'll be lucky to get 100 cycles out of the battery.

What is your source for this? This seems very wrong.
Also what is your source on "no pauses" having an influence?

[MVetter]

What is your source for accelerated degradation when empty?
From all I know, this is wrong.

This is what I was told explicitly by Luke Workman, a friend who is one of the brightest minds in the battery world today. He also was responsible for redesigning Zero's 2012 packs to not catch on fire. Now he and his equally brilliant wife, Erika, run a battery consulting and recycling business. https://www.electricgoddess.co/

I'm paraphrasing but Luke said something along the lines of, "one of the worst possible things you can do is leave a battery empty in a hot environment. It rapidly increases growth of dendrites and will cause irreparable damage."

[DerKrawallkeks]

@MVetter
That surprises me, cause both "Degradation Mechanisms in NMC-Based Lithium-Ion Batteries" figure 23 and "Aging of Lithium-Ion Batteries in Electric Vehicles" figure 28 show that a low SOC is beneficial for storing batteries.
I was not able to find any study that got different results.

@T.S. Zarathustra I was not able to find where it says anything about the rule of thumb of 100 cycles at 100% DOD in Lindens Handbook of Batteries.
Where is that rule of thumb described?
This would be a very low number of cycles for todays batteries.

[DerKrawallkeks]

DOD is depth of discharge.
I just want to point out that 100 cycles at 100% DOD is very very far from any cell that is used in any EV. This is less cycle life than even the most extreme high-power cells provide.
I want to stop the spread of misinformation.

[MVetter]

I never said low SoC. I said “empty in a hot environment.”

[DerKrawallkeks]

Empty = low SOC.
"Aging of Lithium-Ion Batteries in Electric Vehicles" figure 28 clearly shows the lower the SOC, the better for storage, both in hot and cold conditions.
Ideal storage SOC at high temperature would be empty.

[DerKrawallkeks]

Almost all batteries are delivered at roughly 50% SOC. This is to make it possible for them to be stored without paying attention to their self-discharge, while staying below the central graphite peak (around 55% SOC) above which the aging effect is significantly higher.

As I already stated with sources, an empty battery is still the best for storage.

The quote that you took from the book has nothing to do with the topic. You intentionally cut it short, since it continues "the effect of storage is more pronounced not only with high storage temperatures and long storage periods, but also under more severe conditions of discharge following storage". It then continues to talk about the influence of the discharge load after storage, which is completely unrelated to my original point about low SOC.

This quote only mentiones high temps and long storage as bad influence. That's not a surprise to anyone I think.

So yea.. I don't really know what you are trying to express here.

[wadejesu]

Did someone say there is a 14.4  FXS version in Europe?

[princec]

No, there isn't.

So far all literature I've come across has stated that LiPo batteries should be stored at effectively just under "50% SOC"*. Storage under effective 0% SOC appears to risk eventual short from metal dendrites and potential explosion. The warmer things are the faster dendrites can form. Does anybody disagree with this?

Cas

* Where "50% SOC" is where the manufacturer finds the median voltage between what they decide is maximum and minimum safe ranges which as MVetter has stated before is 3.65V per cell on a Zero.

[DerKrawallkeks]

It's a PhD dissertation from "Peter Keil". I really like it, good information in there:)

[Fran K]

It's a PhD dissertation from "Peter Keil". I really like it, good information in there:)

Is this what you are refering to?
https://www.researchgate.net/publication/282252570_Aging_of_Lithium-Ion_Batteries_in_Electric_Vehicles_Impact_of_Regenerative_Braking

It is from 2015 and has a co author.  He seems in the consulting business now.

[DerKrawallkeks]

Hello,

No, as I said it's a PhD dissertation.

http://mediatum.ub.tum.de/doc/1355829/document.pdf

[DerKrawallkeks]

The paper talks about NMC, the most popular EV chemistry, that zero also uses.

The two statements I have already covered and correctly quoted, and there's diagrams showing exactly what I mentioned. Go back to one of my previous post to find the corresponding figures.

[okanor]

Thanks a lot ! Do you have a study supporting this and comparing many charge cycle options ? I would like to know what i save to see if it is woth doing it !

I mean... you can literally cite tables 2 and 4 from the original study you linked for confirmation. Just apply the data to a Zero pouch and extrapolate that into pack values. For example, in Table 4, take any of the cell voltage values and multiply them by 28, because Zero packs are in a 28S configuration.

4.2 x 28 = 117.6 <-- this is beyond Zero's allowed voltage. They soft cap their cells at 4.157vdc
4.15 x 28 = 116.2 <-- basically 98% on a Zero
...
...
3.9 x 28 = 109.2 <-- ~79% on a Zero
3.65 x 28 = 102.2 <-- 50% on a Zero
...
...
all the way down to
3.39 x 28 = 94.92 <-- empty Zero

I own a 2022 Zero S (picked up in Jun 2022 with 30 miles and now I have 2700 miles) and there is no automatic method to charge to only 80% like there appears to be on SR models and above. I have flow model helicopters for 16 years and am pretty familiar with Lipos they use. My model batteries live a hard life (4.5-5ah 6-12s setups) and last 3-5 years which is much higher than most in the hobby, very often they are asked to deliver 150+ amps during spikes and average 45-65amps over a 3-8 minute flight. I charge up to 4.15v per cell (95% in this case) and run them to about 3.77v per cell (30% in this case) between the speed controller info (amps/volts) we can calculate ah consumption then compare it to when we charge. This method has worked well for me for 10+ years now. I have been researching the internet to find more information on NMC batteries. I am happy to see that Zero cuts off @ 95% charge state. When this example above states "all the way down to 3.39 x 28 = 94.92 <-- empty Zero" What is 3.39v per cell? Is that 20%, 30%, 40% remaining of the battery? I haven't found any good voltage charts to show. I completely understand voltage isn't an exact method, but if you let the battery sit and stabilize it's a decent indicator.

My overall concern is when/if I run my battery down and I only get 30 miles can I purchase a new one from Zero? Do they offer anything like this, my research says no. Many thanks to all the folks that have taken the time to provide information here and via youtube videos, super helpful.

If I ride my Zero S "7.2" like a motorcycle for fun I get 40-45 miles (I'm 250lbs this is in 60-degree weather) If I really, really, really try to be as efficient as possible and not get run over doing 35mph roads doing the speed limit I can get 70-80 miles. Mixed (60mph max) and 35mph roads pretty equally split I can get 55 miles. I've reached out to Zero with these questions but don't get any answers. I bought my bike with 7 charge cycles and I currently have 92. I am in Missouri outside of St. Louis so chargers can be challenging to find along any route. I am a techy nerd so I am always tracking ride data and so far I see no indication of degration but perhaps I don't know where to look. I do have logs I pull monthly so I can track any differences.