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I am trying to understand the best way to preserve the battery whilst also charging for max convenience. I have a home charger PodPoint and often charge to 100%. I seem to get the message that charging to 100% of battery capacity is foolish. Also on a rapid charger - seems to be advised to charge to 80% - not sure if this is to preserve the battery or because of the slow down in speed.

Can anyone point me to a thread or a website that will answer my questions please? I currently have a nagging feeling that I'm doing something destructive and with such an expensive car I'm eager to look after it.

Also - if we can only charge to 80% surely that massively diminishes the range?
 

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Charging to below 80% (I set mine to 70%) reduces stress on the battery, ultimately lengthening its life.
This charge threshold is the same for AC or DC except high current DC charging does other bad things to the battery (heating it mostly).
This doesn't affect range, if you're going on a long trip then charge to 100%. How often do you need the full range? No different to a petrol car with half a tank...
 

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There is no great answer, but my experience with a Hyundai Ioniq is, after 3 years and 30,000 miles with varied charging, no deterioration. The car bms will look after it for you, so charge as your need dictates.

At home I use my 7kW charger, adding 10kW often, as that is fine for my journeys locally. I travel 350 miles to Scotland, full charge on leaving, as much charge as needed with safety, to the next charger, which often means to 94% in my 28kWh car.

There is virtually no record of battery degradation with Kia/ Hyundai, so you will have to make your own choice as there is no data, just good anecdotal evidence that they have an excellent system.
 

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John.
 

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This may be relevant to a LEAF, but not all cars. BMS from different manufacturers have significant differences.
 

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John.
 

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Charging to 100% is not good. Period. It is not so bad if you start using the car immediately after charging, but filling it up to 100% puts extra stress on the battery nonetheless.

There´s ample information on this subject over at BatteryUniversity.com. See e.g. this page:
TL;DR 300 - 500 cycles when charging at 100% for NMC cells, 600 - 1000 cycles when charging to 85-90%, 1200 - 2000 cycles when charging to 70-75%.

If you are going to sell the car in 3 years time, then by all means charge what you want. If you care that the next owner gets a decent car, or if you want to keep the car for a longer period, then try to charge to 80% or better even 70% for daily use and only charge more if the trip requires it. Charge to 100% once a month to balance the cells.
 

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There is no great answer, but my experience with a Hyundai Ioniq is, after 3 years and 30,000 miles with varied charging, no deterioration. The car bms will look after it for you, so charge as your need dictates.

At home I use my 7kW charger, adding 10kW often, as that is fine for my journeys locally. I travel 350 miles to Scotland, full charge on leaving, as much charge as needed with safety, to the next charger, which often means to 94% in my 28kWh car.

There is virtually no record of battery degradation with Kia/ Hyundai, so you will have to make your own choice as there is no data, just good anecdotal evidence that they have an excellent system.
My Leaf didn't show any degradation after three years either, and today (9 years old) it's only got about 55% of new capacity.

I'd recommend charge limit at 80%, plug it in every time you get home to allow it to get up to that level overnight, and as and when you need to do a longer journey pop it up to 100%. You'll need to do that about 2 hours before you leave to go from 80% to 100%.
 

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Charging to 100% is not good. Period.
But cars do not charge to 100%, that is the difference, when Niro is at 100%, it is well below 100% of this charge figure. So charging to 100% with a Niro does not lead to these problems. Balancing of Kia/ Hyundai batteries seems considerably different to Nissan.

Equally,
then try to charge to 80% or better even 70% for daily use and only charge more if the trip requires it. Charge to 100% once a month to balance the cells.
is what I suggested, but I am not yet convinced about how Hyundai balances the batteries as they do not have the long slow charge when at 100% like some cars.
 

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But cars do not charge to 100%, that is the difference, when Niro is at 100%, it is well below 100% of this charge figure. So charging to 100% with a Niro does not lead to these problems. Balancing of Kia/ Hyundai batteries seems considerably different to Nissan.
It is commonly accepted that the e-Niro has a 67 kWh battery, out of which 64 kWh is available. That is only a margin of 5%. It is very likely that a part of that margin is used to prevent draining the battery to 0%, which is really bad s well. So maybe instead of 100%, you charge the battery to 97%. That will alleviate some of the stress, but it is still a considerable amount of charge and a far cry from 80% or 70%.

The Niro has a very big battery and if you´re not doing 250 miles every day, applying a conservative charging regime will only be good for the battery and will not restrict the usability of the car.

About the 100% once a month, that is even a recommendation that is in the e-Niro manual.
 

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Thank you everybody. It does seem that the issue isn't without controversy, but perhaps the safest solution is to charge regularly to 80% and occasionally to near 100%. Appreciate the replies.
I think you need a full 100% charge in order to balance the battery cells. As mentioned the manual suggests once a month.
 

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Thank you everybody. It does seem that the issue isn't without controversy, but perhaps the safest solution is to charge regularly to 80% and occasionally to near 100%. Appreciate the replies.
Equally stressing as charging to 100%, is repeatedly discharging to very low levels. For best possible cell longevity try to avoid (only where possible/convenient) frequent both full and empty (Except an occasional 100% presumably for balancing purposes).

Peter
 

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One could observe the cell voltage at both 0 and 100% SoC displayed to understand the situation in the grand scheme of Li-ion batteries. We know that the Kona achieves 4.16 to 4.18 V at 100% but I've never seen a value at 0% - volunteers are needed for that. Although a Li-ion energy/voltage curve is non-linear, particularly at the bottom, 4.16 is close enough to the generally accepted maximum of 4.20 that I would certainly consider 100% SoC displayed to be something I would try to avoid if not needed for imminent use.

I'll also note that the Kona's displayed SoC appears to be simply a proportion of the SoC BMS, so that 5% is the difference only at 100%; see the graph below covering a 300 km round trip. As for cell balancing it's been theorized that this happens when charging around the 98% mark. If the BMS considers the cell differential to be within tolerance (approx 0.02 V), the displayed SoC jumps immediately up to 100%, again check out the graph. I don't have a similar graph when balancing was required, so can't quite prove it yet.

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I am trying to understand the best way to preserve the battery whilst also charging for max convenience. I have a home charger PodPoint and often charge to 100%. I seem to get the message that charging to 100% of battery capacity is foolish. Also on a rapid charger - seems to be advised to charge to 80% - not sure if this is to preserve the battery or because of the slow down in speed.

Can anyone point me to a thread or a website that will answer my questions please? I currently have a nagging feeling that I'm doing something destructive and with such an expensive car I'm eager to look after it.

Also - if we can only charge to 80% surely that massively diminishes the range?
Roo lot of myths out there. Look at pluglife TV on YouTube.

Here is a good starter.



Sent from my iPhone using Tapatalk
 
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The key points are that battery university is right and so are the guys that go to 100% indicated in the car.

If you REALLY were charging your car to 100% when it indicates 100% it would be bad, but the car never really charges the cells to 100%, it has that "buffer" to protect your battery life.

Most important is to not always top off, but don't discharge deeply. Read better sites than battery university, when you find a site that explains that 1000 charges of 50% makes the battery last longer than 500 charges to 100%, you are on the right site and getting the information that the battery manufacturers themselves indicate... the batteries will give you more lifetime watt-hours if you don't deep discharge.

You can stop worrying about charging to 100% because you cannot charge the actual battery to 100% more like 90-95%.

Greg
 

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There is a small problem with this concept of "false" 100%. After some use, it becomes real 100% as the batteries wear, and as a result you will be charging closer and closer to real without know it.
 

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You can stop worrying about charging to 100% because you cannot charge the actual battery to 100% more like 90-95%.

Greg
Iḿ sorry but I think you'ŕe wrong, The Niro has a 5% buffer and it's very unlikely all of it is used at the top. So no way is 100% actually 90% and it's dubious it's even 95%. It's more like 97% or 98%

It is also a known fact that charging to a lower percentage is better for the battery. Charging to 90% is better than charging to 100% and charging to 70% is better than 80%. I agree people should not fret about it, but it would be common sense to only charge to 70% or 80% if your daily use is less than 150 miles, and charge to 100% only when you plan a long trip.
 

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I don't think we are getting the whole story on how the Niro really works, that is why I guessed at 90%. All this speculation and penchant for 95 vs 90 vs 100 is exercise.

If you actually open up the battery and read the voltage on the cells, I will believe you. Otherwise it is speculation.

So do you have any real data to support your 97% or 98%? You have the manufacturer's spec on the cells? You put an accurate voltmeter on the cell? No, we can only make guesses.

I've used BARE lithium batteries for years, and there's variation between manufacturers you have not accounted for, and nowhere in this thread has anyone used an accurate voltmeter, and remember the SOC of the battery is determined by less than tenths of a volt.

If you worry, go ahead and pick your typical max charge level at any number you want. I charge my car when it gets around 50%, and let it charge to 100%. Check back with me in 5 or 6 years.

Greg
 

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I don't think we are getting the whole story on how the Niro really works, that is why I guessed at 90%. All this speculation and penchant for 95 vs 90 vs 100 is exercise.

If you actually open up the battery and read the voltage on the cells, I will believe you. Otherwise it is speculation.

So do you have any real data to support your 97% or 98%? You have the manufacturer's spec on the cells? You put an accurate voltmeter on the cell? No, we can only make guesses.

I've used BARE lithium batteries for years, and there's variation between manufacturers you have not accounted for, and nowhere in this thread has anyone used an accurate voltmeter, and remember the SOC of the battery is determined by less than tenths of a volt.

If you worry, go ahead and pick your typical max charge level at any number you want. I charge my car when it gets around 50%, and let it charge to 100%. Check back with me in 5 or 6 years.

Greg
What's critical there is how quickly do you drive after getting to 100%. If it's an hour later, ok. If it's 12 hours later, and you charge every three days, well that means for every year of ownership you are letting it sit at 100% for 60 days. After ten years, it's sat at 100% for 600 days. Would you charge a battery to 100%, leave it in a box for almost two years, and expect it to still have 100% capacity.....?
 
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