Charging to only 80% when not using timed charging?

[MassDeduction]

Hi all, this is my first post to the forum, so hopefully this isn't a topic that's been covered to death (I didn't find a thread, but perhaps I missed it!).

I see that there's an option to charge to only 80% when using timed/metered charging. However, I don't see that option when metered charging is turned off. When timed charging is turned off, does it charge to 80% or 100%, or is it selectable in some way that's not obvious to me? This is on a 2016 Soul EV. Thank you very much!

 

[JejuSoul]

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Yes, charging will stop at 80% automatically, only when using timed charging?
Otherwise it will charge to 100%. To get a lower number in a car without the 80% setting you must manually stop the charging. This is best done by setting the charge timer to start a few hours before you leave in the morning. Then manually stopping the charging when you leave.

The settings option looks like this on my car (a 2015).
This is how I normally charge my car. At home, from 11.10pm to get the cheapest electricity rate, finish at 80% to improve battery longevity.



This setting was removed in later cars because of a stupid EPA range rule. The rated range for an EV was reduced if it had such a setting. Hence Kia and Nissan both removed the 80% setting to artificially increase the stated range. Logically it is the EPA that must be blamed for enforcing the stupid rule, not the car companies. Green Car Reports 2016: Why EPA range-ratings are inconsistent and confusing for electric cars.

Charging to 100% should be avoided as much as possible, especially in hot weather. Occasionally doesn't matter, and is even useful to properly calibrate the battery. To avoid battery degradation it is better to charge the battery between 20% and 80%.

 

[MassDeduction]

Wow... just, wow. That's ridiculous. Thanks for bringing me up to speed on that. I have the same setting and was hoping that it could be set to do opportunity charging up to a max of 80% as well, but clearly not from what you're saying. The overnight timed charging to 80% is all well and good, except sometimes you want to charge during the day between trips. I suppose the solution is to use the second slot for timed charging, and set it to begin a few minutes after you set it. That way you can keep the overnight charging set as well.

There are going to be a lot of people replacing e-car batteries years before they need to because of this EPA policy, I fear. And it's a silly policy, so long as people can change from 80% to 100% for the times that they need to.

 

[JejuSoul]

... except sometimes you want to charge during the day between trips. I suppose the solution is to use the second slot for timed charging, and set it to begin a few minutes after you set it...

Yes. I occasionally do that. I prefer to use the first slot because once it is set correctly, and works, you are confident that it will always work.
Using the second slot for one-off extra charges has been more error-prone. For example if you accidentally put in 'am' instead of 'pm'. The middle blue light starts blinking suggesting the charging is about to start, but in reality it is waiting another 12 hours.

 

[MassDeduction]

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[...]This setting was removed in later cars because of a stupid EPA range rule.[...]

Any idea what model years it was removed from? It seems the 2015 and 2016 had it. Which years do not?

 

[IanL]

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[...]This setting was removed in later cars because of a stupid EPA range rule.[...]

Any idea what model years it was removed from? It seems the 2015 and 2016 had it. Which years do not?

2018 does not, to my sorrow. I have to estimate how long it will take to get to 80%.. At present, I am using the 2.3kW ICCB (in-cable control box) and it takes about 2 hr for 10%.

 

[JejuSoul]

...Any idea what model years it was removed from? Which years do not?

The 3 years 2017-2019 do not have this setting.
The newest cars have a sliding scale, allowing you to set any value.
For some reason this is allowed by the EPA, but not when it has pre-defined choices.-

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You can see the change in the rated range for the Nissan Leaf in the image below.
The only difference in the car was the removal of the 80% option.



The 80% option on the Soul EV was removed for the 2017 but the EPA adjustment didn't happen until the next year.
This made the battery improvement of the MY2018 look greater than it actually was.



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[FLKiaEV]

Just want to say two things: First, that the EPA reducing an EV's estimated range because the user can select not to fully charge is like penalizing ICE cars because their owners can decide not to fill up the gas tank all the way. So stupid.

Second, whenever I select 80% on that screen (2016 Kia Soul EV+ here) and try to save it, I get a message saying that the choices were not saved. Anyone know why?

Thanks.

 

[MassDeduction]

Here's a question that I am guessing at the answer to, but would prefer to be certain rather than to guess. When it charges to 80%, is it charging to 80% of the total capacity or 80% of the useable capacity? Because staying under 80% of the total capacity is what's actually important, though even lower is even better (presumably you're not draining below 20%, that is). On the 2017 and earlier Soul EV, for example, charging to 80% of useable capacity is actually charging to 75.4% of total capacity, by my math.

Edit to add: Do we know whether the top and bottom SOC buffers are exactly equal in size? Or is one a little larger than the other?

 

[FLKiaEV]

My guess is that the 80% is the usable capacity not the total capacity because the 100% is the usable capacity and it would make sense that it would follow the same methodology. That being said I wish there was an option to charge to 90% which is a good compromise for range vs battery life.

And I've heard it said that keeping the battery at a 100% SOC for an extended period of time stresses the battery, but if it is only charged to 100% of USABLE capacity does this still apply? In other words, is it okay to just charge to 100% each time (not every night, because that actually IS detrimental to the battery) knowing that it's really not 100%?

 

[ksoul2084]

I'm pretty sure its a sliding scale, so 100% is bad, 90% is less bad, 80% is even less bad, etc. There is no "magic number", so for example, if you were able to keep your battery between say 40% and 60%, that would be optimal, but realistically the degradation isn't linear so for practical purposes 20-80% is fine.

I too wish there were more options than just 80% on the timed charging.

 

[FLKiaEV]

Apparently after 2016 Soul EV owners don't even have this choice, not due to Kia's decision but because of how the EPA rates range for EVs. It's so dumb: If a customer can choose to have their battery charged to only 80% then the range has to be listed as that number. (Funny that they don't require ICE cars to claim this too, since they can also "fill up" less than a full tank).

 

[IanL]

Apparently the 2020 models have a sliding scale, i.e. they can select any value at all - the EPA could not cope with that, so the objection vanished. It would be nice if they applied that change as an upgrade to previous models.

 

[ksoul2084]

Apparently after 2016 Soul EV owners don't even have this choice, not due to Kia's decision but because of how the EPA rates range for EVs. It's so dumb: If a customer can choose to have their battery charged to only 80% then the range has to be listed as that number. (Funny that they don't require ICE cars to claim this too, since they can also "fill up" less than a full tank).

Actually my 2016 *does* have the 80% charge option, it was the 2018/2019 models with the larger 30kWh battery packs where they had to remove it (I think).

 

[FLKiaEV]

The 2020 Soul EV, unfortunately, will not be sold in the US. Maybe some day I can import one from Canada... More than twice the battery capacity, almost three times the range and MUCH better performance.

 

[MassDeduction]

My guess is that the 80% is the usable capacity not the total capacity because the 100% is the usable capacity and it would make sense that it would follow the same methodology. That being said I wish there was an option to charge to 90% which is a good compromise for range vs battery life.

The option to charge to 84.9% would be desirable, as that's exactly 80% of total charge by my math. GM got this right with the Volt, IMO, as the SOC buffers on that car are 20% so charging it to "100%" is actually charging it to exactly 80%.

And I've heard it said that keeping the battery at a 100% SOC for an extended period of time stresses the battery, but if it is only charged to 100% of USABLE capacity does this still apply? In other words, is it okay to just charge to 100% each time (not every night, because that actually IS detrimental to the battery) knowing that it's really not 100%?

If you charge it to 100% of usable capacity, by my math on a 2016/2017 Soul EV you've charged up to 94.3% of the total capacity. That's higher than ideal, unless you're making a particularly long trip and using the car immediately upon finishing charging.

I suppose what the 2020 Soul EV does is ideal, giving you a slider to set the max charge rate. The range on that car is so good, I'd probably only charge to about 60% as I'd probably still be 40% or above at the end of the day. What's ultimately ideal is that you stick as close to the middle of the battery as possible. So if you anticipate using 30% of the battery for a given day, charging the car up to 65% beforehand would be ideal. Obviously leaving yourself a buffer can be prudent, in case of the unexpected. Ultimately you don't want to stress yourself out, so it depends how deeply into the weeds you like getting.

 

[FLKiaEV]

I guess what we REALLY need is a battery formulation that doesn't get stressed even if it's at 100% for extended periods of time, among other things. Solid state is supposedly like this, but I don't expect to see that in an EV for at least 5 more years (though Toyota says they'll have one by 2023. We'll see). SS is the holy grail (super fast charging, thousands of cycles, no chance of fire, extremely high energy density, can be made from common materials such as sodium, etc), but new lithium chemistries are looking good too.