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i was discussing EV and charging limits 20% to 80% with an Electrical/Electronic engineer and he mentioned that batteries "have Memory" regarding the limits that they are charged to , in otherwords if we let the battery consistently run down to 20% the battery will remember that 20% is the lower limit and remember it as zero %

i then searched and came across this on the Net . Battery experts suggest that after 30 charges, you should allow lithium-ion batteries to almost completely discharge. Continuous partial discharges create a condition called digital memory, decreasing the accuracy of the device's power gauge. So let the battery discharge to the cut-off point and then recharge. The power gauge will be recalibrated.

Any thoughts anyone on the 20% to 80% charge limit?
 

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i was discussing EV and charging limits 20% to 80% with an Electrical/Electronic engineer and he mentioned that batteries "have Memory" regarding the limits that they are charged to , in otherwords if we let the battery consistently run down to 20% the battery will remember that 20% is the lower limit and remember it as zero %

i then searched and came across this on the Net . Battery experts suggest that after 30 charges, you should allow lithium-ion batteries to almost completely discharge. Continuous partial discharges create a condition called digital memory, decreasing the accuracy of the device's power gauge. So let the battery discharge to the cut-off point and then recharge. The power gauge will be recalibrated.

Any thoughts anyone on the 20% to 80% charge limit?
I chased a similar thought because I ended up with a car that has the total capacity of what my daily use is and was determined to use the car based on Hyundai owner manual and other technology snippets on the web. I now understand that there is a lot of information on DoD and SoC on the net and they are related to a single cell and for the most part highly accurate. The shift in gear of the single battery recommendations to the HV batteries in car lies in the fact that although HV car batteries contain the singe cells that are so prolifically talked about on the net, are made up of cell packs each containing a bunch of peski cell. There are several cell packs (12 to be exact in the Ioniq EV) and they are all managed by the BMS (battery management system), a secret sauce of each car manufacturer that is pretty much undisclosed outside of OBD II device polls of data.

In laymen/laywomen terms, think about your battery as a elementary school with unruly kids (cells) , all managed by a teacher in a classroom (cell packs, 12 class rooms in the Ioniq EV school) , and a Principal/Provost (BMS).

The stuff that I have read (mostly batteryuniversity.com) relates to the unruly kids (cells) and are 100% accurate. However we keep forgetting the Teachers (cell packs) and Provost (BMS). Imagine an inspection of the school. I am sure the provost may instruct all the teachers to place kids with behavioural issues in the closet (figure of speech fellas) and have a pleasant walk through @ inspection.

Personally I am battling with the 20%-80% thought. Here in the South (US) 60% (78 miles) is basically in many cases a drive to work and back, not forgetting the grocery store or kids soccer. I cannot imagine the car range being 80 miles. Now the PlugShare app does brand te Ioniq range @ 80 miles. So there may be some value to that or Plugshare took the story off batteryuniversity.com.

Although Ioniq EVs have been around since late 2016, there are no stats on people using it byond the 80 miles/day. Given the cost of the battery replacement no one wants to be a statistic. The 80 miles range may also be the reason why Hyundai does not sell the car in the south (US) where distance is just a fact of life.

I am banking on the fact that the Hyundai BMS does an excellent job for 100K
 

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You are mixing up a number of battery types and technologies. Nicad batteries exhibit a memory effect, not lithium batteries. Some laptop and other electronic manufacturers did require occasional full discharge and charge cycles to effectively measure remaining capacity (like Apple), but not all manufacturers (I remember specifically Sony video cameras time remaining meters were unbelievably accurate) and it in no way affected actual capacity, just that device's ability to measure it. And again, these devices usually used nicad batteries.

The lithium based battery packs in cars have hundreds of smaller cells. It is recommended that once a month or so you charge to 100% to balance the voltage of all these cells. Otherwise, discharging completely or charging completely does potentially hurt battery longevity, thus keeping charge in the middle range is best. Charging rates are impacted by ambient and working temperatures and active temperature controls make a difference between different maker's cars. In general though, lower rates are better as they heat up the battery less. Most makers warn against frequent "fast" charging - which usually means DC fast charging. Most AC rates are OK for most cars.

20 to 80% charge range is conservative and advisable. Throwing a wrench into that range is that there is typically a hidden reserve built in by car makers to help stay in this range. So for PHEVs, you can just safely charge to 100% displayed knowing there is a safety margin built in. For BEVs, typically it is really up to the owner to manage maximum charge.
I'm hardly an expert and hoping above is an accurate summary of best practices.
 

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There are several owners on the forums with high miles now and to the best of my knowledge, zero observed battery degradation. The IONOIQ BMS appears to be superb. The practice of generally trying to keep the battery between 20% and 80% is accepted best practice for lithium ion battery packs and should provide the best approach to maintaining SoH.

I've got 68,000 km on the clock and my OBD II scanner shows all the original reserve is still there. On the road I've also not seen any range loss. (Other than seasonal). May owners plug in every time they're home and leave it charges at 100% till they need to drive. They similarly haven't observed any range loss.
 

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My 2017 Ioniq EV has 80,000 miles now after driving an average of 100 miles a day for the past 2 years and 7 months. My Southern California driving experiences have been such that the range has degraded from 124+ miles per charge initially down to 90+/- miles per charge. Some times I get only 70 miles per charge driving the full distance on cruise control at 75 mph. At that speed it's expected to lose range due to drag forces. Other times, I get about 100 miles driving in stop and go traffic jam or behind a truck for the full distance. Of course there's very little drag there. I have a hunch that it may not be the battery degradation. Maybe it's a memory thing, but every expert says lithium battery doesn't have memory.

So here's my data that may help the experts, when my EV was new, it took about four and a half hours to charge full from completely empty. Now it only takes about three and a half hours to charge full from completely empty. Since the battery capacity is twenty eight KW and my home charger is a level two with a [email protected], it made sense when the car was new. But now, it's not charging full or it thinks it's full at three and a half hours of charge. The range estimate at full is around 110 now. Of course it never get's that.

I've heard some say that a few cells in the battery bank could go bad due to bad circuit connection and it can be replaced without replacing the entire battery. Others say it's degradation. And others even say memory.

I'll never know since my EV is leased and I will be returning it in a few months and I don't want to pay for the service. Apparently, my lease has unlimited mileage and unlimited maintenance services for three years, but the maintenance service expired at 50,000 miles according to my dealer. (Is this true?)

Anyways, I am satisfied with my EV. With new EV brand and models being developed, it seams to be getting better for the most part. I don't expect it to be perfect.

Good luck all you EV drivers, you are the early adapters so don't expect it to be perfect.
 

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That's quite an alarming reduction in range, especially after only 80,000 mi (+/- 125,000 km). Mine has 70,000 km and is still as good as the day it was new. Do you know, was the change gradual or relatively sudden? I see you're down south, so I assume that cold weather is not a factor. Perhaps the heat is? How much do you fast charge? What are your typical ambient temps?

Do you have access to a BlueTooth OBD II scanner. If so plug it in and with the canIoniq24 app check things out. If you have "bad" cells, you'll see it there.
 

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That's quite an alarming reduction in range, especially after only 80,000 mi (+/- 125,000 km). Mine has 70,000 km and is still as good as the day it was new. Do you know, was the change gradual or relatively sudden? I see you're down south, so I assume that cold weather is not a factor. Perhaps the heat is? How much do you fast charge? What are your typical ambient temps?

Do you have access to a BlueTooth OBD II scanner. If so plug it in and with the canIoniq24 app check things out. If you have "bad" cells, you'll see it there.
The change was relatively sudden less than a year ago. I fast charge almost every day as I drive more than my car's range. It's about 60-70 degrees in the winter and 80-90s in the summer.

I don't have access to a Bluetooth OBDII scanner. Also, don't see canioniq24 app on the Apple App store.
 

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I agreed with Jonboy, you've probably utilised the vehicle in the worst possible way in terms of battery degradation - high discharge rate and then fast charge and all in a fairly warm environment. As we all know, heat is the biggest factor in degradation with lithium ion batteries. That said, it's good to see how well it's stood up to that abuse. Pity you don't have access to a scanner it would have been most interesting to "see" what's going on with your battery. Btw, canIoniq24 is on the Android app store.

Good to hear that everything else about the car is great though. Gives me confidence that mine will stay the course.
 

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I agreed with Jonboy, you've probably utilised the vehicle in the worst possible way in terms of battery degradation - high discharge rate and then fast charge and all in a fairly warm environment. As we all know, heat is the biggest factor in degradation with lithium ion batteries. That said, it's good to see how well it's stood up to that abuse. Pity you don't have access to a scanner it would have been most interesting to "see" what's going on with your battery. Btw, canIoniq24 is on the Android app store.

Good to hear that everything else about the car is great though. Gives me confidence that mine will stay the course.
Car's doing great. Much better than an ICE vehicle would do. In addition to the Southern California coastal driving, I do Las Vegas about once a month and sometimes it get's really hot. Like 144 degrees hot at Baker, CA where I would fast charge at maximum rate of around 70 Kwh... no problems.
 

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Here lies the deficiency of an air cooled battery pack. Even when used like you use the car, that drop in range is alarming indeed, the drop being 28% not even including the hidden reserves of a new car.
 

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Here lies the deficiency of an air cooled battery pack. Even when used like you use the car, that drop in range is alarming indeed, the drop being 28% not even including the hidden reserves of a new car.
So are you saying that the liquid cooled battery pack doesn't have the drop in range? Let me share some additional data. Prior to owning the Ioniq EV, I owned a BMW i3 BEV and I had the same driving pattern for about 3 years. Well the i3 battery degraded much faster than the Ioniq and the I3 was liquid cooled.
The experts say that the liquid cooled batteries have it's own issues such as lower heat transfer rates. So, let's leave the technology comments to the experts and not make any fallacies about the different technologies. Afterall, we are in the pioneering stages of EVs. Many people are looking to the few drivers of EV to understand how it will replace the ICE vehicles.
 

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Lower heat transfer rates for liquid cooling? Must be really bad design/implementation to overcome basic physics. All I can say is that it was a good thing VW air-cooled engines were so easy to pop out and overhaul.
 

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So are you saying that the liquid cooled battery pack doesn't have the drop in range? Let me share some additional data. Prior to owning the Ioniq EV, I owned a BMW i3 BEV and I had the same driving pattern for about 3 years. Well the i3 battery degraded much faster than the Ioniq and the I3 was liquid cooled.
The experts say that the liquid cooled batteries have it's own issues such as lower heat transfer rates. So, let's leave the technology comments to the experts and not make any fallacies about the different technologies. Afterall, we are in the pioneering stages of EVs. Many people are looking to the few drivers of EV to understand how it will replace the ICE vehicles.
My point is that the regular BMW i3 battery will degrade noticeably but the average Ioniq doesn't show any degradation. The fact that your car has such a high level of degradation is very rare and if it is due to the driving conditions and charging habits then it is very much caused by inadequate cooling that cabin air is capable of.
 

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I agreed with Jonboy, you've probably utilised the vehicle in the worst possible way in terms of battery degradation - high discharge rate and then fast charge and all in a fairly warm environment. As we all know, heat is the biggest factor in degradation with lithium ion batteries. That said, it's good to see how well it's stood up to that abuse. Pity you don't have access to a scanner it would have been most interesting to "see" what's going on with your battery. Btw, canIoniq24 is on the Android app store.

Good to hear that everything else about the car is great though. Gives me confidence that mine will stay the course.
Ou Boet, Amazon just delivered a bluetooth OBD II reader to my door. Now I just need the CanIoniq24 app. Can't find anyone in my neighborhood that has an Andriod. Everyone is Apple. Does it work on Windows Surface Pro?
 

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As far as I know, it's only available on Android. Bjorn had an app he used in his new IONIQ range testing videos. Check his YouTube challenge and see if you have get hold of that.
 

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As far as I know, it's only available on Android. Bjorn had an app he used in his new IONIQ range testing videos. Check his YouTube challenge and see if you have get hold of that.
I got a hold of an Android Smartphone. I don't see the canioniq24 app? Are you sure that's what it's called?
 

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Sorry, slips of the finger. It's called canIoniq24 on my phone, but canIoniq in the app store. Here is the link --> canIoniq
 

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Ou Boet, I've watched Bjorn's Youtube video and ran the Canioniq app with the OBDII reader. Unless I am doing something wrong, the Canioniq app's seams to output erroneous data. Even Bjorn was saying that when he did his degredation test. Any thoughts?
 
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