Info in Manuals about EV Charging; a Rant

[Ed Zwieback]

I have 5 years of experience with a '15 Kia Soul EV, and so I expected to transition easily to managing EV battery charging with my '20 Kona EV; but not so.
The Kona battery charging info is scattered over the many manuals provided, and, surprising to me, the management methods and info differ from the Soul EV . It's complicated!

Specifically, I want to know how to set , or manage, the maximum charging limit when using "Immediate charging" (page H11 and H17). It's probably somewhere but can't find this info. Does Immediate Charging use the Scheduled-charging charging-limit?
With the KIA Soul EV, Immediate charging results in 100% charging limit only.
Time at 100% charge should be kept to a minimum, regardless of EV.

Rant: I have never used the portable charger (Level 1) that came with the Soul EV and don't expect to use it with the Kona EV. Level 1 charging has got to be the last resort.
The Kona EV System Overview (H pages) has 10 pages explaining use of the portable charger; that's 16% of the whole EV System Overview.

Finally, to me, all the info/process for Departure Times and Climate-Schedules get into the way of basic Battery Charging management.

 

[KiwiME]

It's possibly the prior Soul experience that triggered this confusion. This is my first EV, I didn't find it hard and everything works.
The charge limiter works independently and always applies, 10 to 100%, separate for AC and DC.
If no charging schedule is programmed or enabled then it always starts when the EVSE is plugged in and makes power available.
If a charge schedule is enabled, then the schedule applies unless you override it with the button a short time after plugging in.
I don't use the departure time even though it curiously has to be set to enable a charging schedule. As best as I'm aware it only determines when to start preconditioning. However, it may also trigger early charging when "priority" off-peak is set, if the period until the departure time does not allow the expected charge to complete when started at the start of the off-peak period.
The manual is pretty horrible but the area I think it covers poorly are how an AC charge can be terminated at the car, basically unlocking the doors by any means.
As for the trickle charger, that's all I use at home. It gives me 80 km overnight, easily more than I need. A higher power EVSE would cost me around $3k installed because it has to be done by a licensed electrician and we don't have those convenient dryer sockets. There's a DCFC one block from here if I need a quick boost.

 

[hieronymous]

As for the trickle charger, that's all I use at home. It gives me 80 km overnight, easily more than I need. A higher power EVSE would cost me around $3k installed because it has to be done by a licensed electrician and we don't have those convenient dryer sockets. There's a DCFC one block from here if I need a quick boost.

You could look at the following, which I use no problems - needs a 32A caravan socket installed. Mine is via the board with a trip/rcd combo.
https://www.evolutionaustralia.com.au/product-page/portable-evse-15-32-amp-charger

 

[Toolworker]

Rant: I have never used the portable charger (Level 1) that came with the Soul EV and don't expect to use it with the Kona EV. Level 1 charging has got to be the last resort.
The Kona EV System Overview (H pages) has 10 pages explaining use of the portable charger; that's 16% of the whole EV System Overview.

A lot of those pages are repeated information.

The H pages go through the whole charging process, beginning to end, for Level 2, then for DC Fast Charging, and then for Level 1. So some of that stuff is repeated three times. That's useful if you're trying to use the manual the first time you charge, but annoying if you're trying to understand the car.

Slightly OT, but my charging peeve is that the Kona doesn't allow for different schedules for weekday/weekend and summer/winter. So it is of limited use for California time-of-use rates, where the rates can vary 250% or more. But the Kona does have a variety of charging rate and limit options. Too bad it doesn't say what the current amounts are for the charging rate options.

I have a Juicenet-enabled EVSE which does have weekday/weekend, so I use that for TOU control and always charge on the more restrictive summer schedule. My previous cars - Volt and plug-in Prius - had weekday/weekend and summer/winter.

 

[apu]

With the KIA Soul EV, Immediate charging results in 100% charging limit only.
Time at 100% charge should be kept to a minimum, regardless of EV.

Sorry I don't have much to add other than don't worry too much about the 100% charge thing, your Kona will never reach an actual 100% SOC. Unlike other EVs like Tesla or perhaps even your previous Kia when the display says its 100% the actual BMS SOC is 95%.

 

[Tim94549]

...... Unlike other EVs like Tesla or perhaps even your previous Kia when the display says its 100% the actual BMS SOC is 95%.

REALLY ???????? What's the point? Especially if you do a LONG trip?

 

[KiwiME]

What's the point?

Don't worry about it and forget you ever saw it ... it's a margin used by Hyundai and LG-Chem to manage battery life. In mine it's only 4%.

 

[apu]

REALLY ???????? What's the point? Especially if you do a LONG trip?

As Kiwime indicated its part of the hidden buffer used mostly to protect your battery. Its a good thing. You don't get any less of the rated range or the full 64kwh( actual battery size likely around 67kwh) , or at least until that buffer disappears due to normal battery degradation. The point of my post was that you don't have to get overly concerned about charging to 100%, charge to whatever you need guilt free . This article explains it well https://cleantechnica.com/2018/08/26/the-secret-life-of-an-ev-battery/

 

[Ed Zwieback]

Seems that EV Battery Charging is still a debatable topic, and not helped by these lame Kona-EV manuals.

I still believe that for best practice; time at 100% charge should be kept to a minimum, regardless of EV.

Plenty of basic info available, such as from: https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
"Environmental conditions, not cycling alone, govern the longevity of lithium-ion batteries. The worst situation is keeping a fully charged battery at elevated temperatures."

and from: https://cleantechnica.com/2018/08/26/the-secret-life-of-an-ev-battery/
"Avoiding very high and very low states of charge. Voltages over 4.15V/cell (about 95 percent state of charge [SOC]) and voltages below 3.00V/cell (about 2 percent SOC) cause more stress on the insides of the cell (both physical and electrical)"

I say "lame Kona-EV manuals" as on page H5: when storing EV for extended length of time, fully charge to 100%. AC charge recommended to keep battery in optimal condition.

Regarding Charge Level values (same as SOC ?), it seems that the manual is hazy; page H8 uses 3 terms while displaying 85%; "Battery", "Energy Info", and "SOC%". I certainly hope that 100% refers to SOC =100%.

 

[Toolworker]

and from: https://cleantechnica.com/2018/08/26/the-secret-life-of-an-ev-battery/
"Avoiding very high and very low states of charge. Voltages over 4.15V/cell (about 95 percent state of charge [SOC]) and voltages below 3.00V/cell (about 2 percent SOC) cause more stress on the insides of the cell (both physical and electrical)"

Correct. But as @apu said,

... your Kona will never reach an actual 100% SOC. Unlike other EVs like Tesla or perhaps even your previous Kia when the display says its 100% the actual BMS SOC is 95%.

IOW the Battery Management System should not charge to the point of overstressing the battery.

I say "lame Kona-EV manuals" as on page H5: when storing EV for extended length of time, fully charge to 100%. AC charge recommended to keep battery in optimal condition.

I don't understand why they don't recommend leaving it plugged in with a charging limit below 100%.

The ability to set a charging limit below 100% is a great feature, and it would be better if the manual encouraged using it except when the full mileage range of the vehicle is needed. I've got mine set to 80%. Perhaps they don't want to raise concerns about battery life or be blamed if a user runs out of juice.

Regarding Charge Level values (same as SOC ?), it seems that the manual is hazy; page H8 uses 3 terms while displaying 85%; "Battery", "Energy Info", and "SOC%". I certainly hope that 100% refers to SOC =100%.

I believe all those terms are used interchangeably and refer to percent of usable battery capacity. They should not use State of Charge or SOC since knowledgeable people, including all of us of course, will misinterpret it to mean actual battery SOC. They should stick with % Battery. 100% Battery = 95% SOC.

 

[KiwiME]

I think there is no reason as consumers to concern ourselves with the BMS's version of SoC; it's of academic interest only. Reported deviations are from 4 to 6% at 100% displayed, where that difference is at a maximum. Every SoC number should be taken as the "displayed" value unless noted otherwise. I'm no more comfortable leaving the car sitting at 96% than I am at 100%. Due to reasons outside of my control my Kona currently sits for 5 days unused every week and I leave it at 50-60%.

During storage I believe another advantage of keeping it on an a home-type AC charger (i.e., one that does not timeout while unused) is that I expect the aux battery periodic charging will not be limited to 10 cycles as it is with the car "off". I've yet to test that theory but will do soon.