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Discussion Starter #1
So as far as I understand you should aim to keep your car around 50-70%, but is it better to keep it plugged in all the time with a limit of 70% or charge to 70% and then only plug it in when it drops to around 50%?

Thanks!
 

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It does depend on the car to some extent.

But you are correct as an initial approach: only charge to a max of 70-80%, unless you are going to need the extra range.

I would suggest that depending on your personal usage, set a lower limit of 20 - 50%, and then charge. What I mean is, I am currently under the impression that it is marginally better to charge more often rather than keep the car over a week or two (if only using it for short trips) and slowly discharge it to 20%.
 
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There is a tradeoff between not charging to (indicated) 100% and the number of cycles. It is not quite cut and dried as that.

Try to minimize the number of charge cycles, try not to charge to 100%, try not to discharge "deeply"... notice that "minimize" and "deeply" are not quantified.

Basically treat it like any other lithium ion battery pack.

Greg
 

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Discussion Starter #5
Thanks, I guess the battery management system will take care of things if it is left plugged in as well...
 

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My understanding is the battery is best left stored at its mid point. If you only do a few miles most days then you could set the max charge to 60% and keep the battery between 40 & 60%.
In reality if you have the max charge set at 70% it will probably make very little difference to the life of the battery if you plug in every day or wait until it gets to 40% before plugging in.

As has already been said, avoid leaving oute sitting for long periods at very high or very low charge.

When I had a Niro I charged to 70 or 80% and plugged in again when the electricity prices were cheap or I was getting below 40%
 

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Discussion Starter #7
Thanks, does the 4+ also cool and heat the battery as required to maintain the "perfect" temperature?
 

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So as far as I understand you should aim to keep your car around 50-70%, but is it better to keep it plugged in all the time with a limit of 70% or charge to 70% and then only plug it in when it drops to around 50%?

Thanks!
Charge it to 100% once a month on your AC charger. This is good for the battery. Using a rapid DC charger regularly is best avoided.

Watch PluglifeTV on YouTube below. He goes through it in laymans terms.

 
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Like I said, lots of different factors and opinions.

One correction, the "storage charge level" recommendation is only for long term non-use and storage. Unless you don't use it for months at a time, not applicable. Certainly you are not "storing" your car battery overnight, or even a few days.

Greg
 

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Straight from the horse's mouth: (TL;DR: 80% to 30%)

The investigation by mediatum is also very interesting and mentions that charging above 80% means extra stress: https://mediatum.ub.tum.de/doc/1355829/file.pdf. See pages 141 - 145. To be noted that charging to high SoC is mainly bad for the cathode. The anode is not affected and anode degradation is apparently the main factor in capacity fade.

Also interesting to note is that they find that current battery technology already allows for batteries to last 15 years. In ideal situations (max 40% DoD and cool storage) batteries would lose 20% over 15 years, our of which only half is due to calendar aging. That means that charging behaviour has a great influence on battery lifetime.

It also implies that possessing a car with a large battery (such as the e-Niro) allows us to adopt a charging regime for day to day use that allows for maximum battery care. In other words, we can stay within the optimum window of 40% DoD and still have enough capacity for daily commutes and errands, and only use the full battery capacity when doing longer trips.

I still haven't read the entire document but plan on doing so. Lots of goodies to be taken from it.
 

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Find myself wondering whether it’s better to take the charge to 100% for a long run, or stick to 80% and require a top up, likely from a rapid. More than just hypothetical as I’m making such a journey on Wednesday.
 

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Discussion Starter #12
Find myself wondering whether it’s better to take the charge to 100% for a long run, or stick to 80% and require a top up, likely from a rapid. More than just hypothetical as I’m making such a journey on Wednesday.
Based on everything I've been reading, 100% is fine as long as you immediately start using it, if you charge to 100 and then leave it, then it is bad. Rapid charging is also apparently beneficially when done occasionally!

I think it seems like we should use it as we need to but keep in mind not to keep it charged too high or too low!
 

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Yes that top off to 100% after a short run seems to be what did damage to the early Leaf batteries.
 

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Find myself wondering whether it’s better to take the charge to 100% for a long run, or stick to 80% and require a top up, likely from a rapid. More than just hypothetical as I’m making such a journey on Wednesday.
If planning a longer trip, have a look at ABRP - www.abetterrouteplanner.com

(if you know it, please disregard :coffee:)
 
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Wow, this is all over the place... leave out the Leaf examples people, non-cooled battery, caused all kinds of degradation issues.

again, leaving the car for a few days at 100% charge is NOT the long term storage situation... I would suggest rather than "partially understanding" these things, do not get your information from these forums, but from sites that are manufacturers of the batteries...

Greg
 

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Wow, this is all over the place... leave out the Leaf examples people, non-cooled battery, caused all kinds of degradation issues.

again, leaving the car for a few days at 100% charge is NOT the long term storage situation... I would suggest rather than "partially understanding" these things, do not get your information from these forums, but from sites that are manufacturers of the batteries...

Greg
Do the physical atoms in the battery "know" they have been at 100% for only a few hours or a few months? No. To them, all time at 100% is the same, regardless of whether it's 6 hours a day (after charging) at 100% for ten years, or being charged to 100% once and left for 2.5 years. Both are bad.
 
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Gosh Edd.... so the effect of charging to 100% is instantaneous? Do you even know the mechanism of the issues with storage at higher levels?

Again, talking specifically about worrying about charging to 100% and "storing", meaning not using the battery for a while..

To make such a statement, without clearly even understanding the mechanism is really wrong. (hint, not all chemical actions nor ion/electron migrations take place instantaneously, this is your major error)

Since you are a moderator, I can see arguing with you is dangerous.

Therefore, I submit evidence from "Battery University" (which in relative terms is battery kindergarten, since it is really entry level).


Please read it in the storage section, you can see degradation after a YEAR for various states of charge.... please start there.

If you dispute this basic information, please provide evidence...

Greg
 

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Here we go again Greg.
Gosh Edd.... so the effect of charging to 100% is instantaneous? Do you even know the mechanism of the issues with storage at higher levels?

Again, talking specifically about worrying about charging to 100% and "storing", meaning not using the battery for a while..

To make such a statement, without clearly even understanding the mechanism is really wrong. (hint, not all chemical actions nor ion/electron migrations take place instantaneously, this is your major error)
But luckily for you, your own link validates what Ed said in his post:

Most Li-ions charge to 4.20V/cell, and every reduction in peak charge voltage of 0.10V/cell is said to double the cycle life. For example, a lithium-ion cell charged to 4.20V/cell typically delivers 300–500 cycles. If charged to only 4.10V/cell, the life can be prolonged to 600–1,000 cycles; 4.0V/cell should deliver 1,200–2,000 and 3.90V/cell should provide 2,400–4,000 cycles.
So yes, charging to 100% is more damaging for the cell than charging it to 100%. It's also in the Mediatum investigation as referenced in my post, with the caveat that 100% charging is worst for the cathode, whereas the anode is more involved in capacity fade.
 

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Hello, you ignored this sentence:

Again, talking specifically about worrying about charging to 100% and "storing", meaning not using the battery for a while..


You even quoted it...
 

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So what's your point? Charging to 100% is bad but storing at 100% isn't?
 
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