Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[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

[T.S. Zarathustra]

A quite important parameter is missing from that study.
"studies were performed with the same type of lithium-ion cell"
Which type of lithium-ion cell?

Some of the most common are:
Lithium Cobalt Oxide. ...
Lithium Manganese Oxide. ...
Lithium Iron Phosphate (LFP) ...
Lithium Nickel Manganese Cobalt Oxide (NMC) ...
Lithium Nickel Cobalt Aluminum Oxide. ...
Lithium Titanate.

They each have different characteristics. Some, like LFP (which is mentioned in the study), are not as sensitive to low or high state of charge as others. LFP also have higher number of charge/discharge cycles than most, while holding similar amount of capacity. LFP have low energy density, and are therefore rarely used in electric vehicles, so are not really relevant to "how to best charge your Zero battery". They are ideal for some other uses.

Cycle count is irrelevant if it's lacking information on how big/long the cycle is. It depends on the exact battery chemistry, and how long you store the battery at each extreme.

Your link contains these statements:
"High battery temperatures increase calendar aging by accelerating parasitic side-reactions. Thus, the battery temperature should be kept low during the long nonoperating periods. " Page 144. So not "the better for storage, both in hot and cold conditions".
"Keeping the SoC at a low or medium level and lowering the battery temperature minimizes calendar aging." Page 141. So not "the lower the SOC, the better for storage".

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]

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.

[domingo3]

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.

You can purchase a replacement battery, but it's unlikely to be a good economic choice as the replacement battery would likely cost as much or more than the entire bike is worth at that point.  It's also not designed to be a user serviceable item, so you'd need some significant effort or dealer support to do the install.