"Battery Discharge Warning" while parked in Accessories mode

This means that you are discharging your 12 V lead acid battery. And when it runs out of juice …

 

Switch ON the car with the brake pedal to prevent 12v battery discharging.

 

..or use utility mode

 

"System" = the car electronics, fans, etc.... stuff that's drawing off the 12v.

 

And just like an ICE you're draining your 12V battery, except, being an EV there's more stuff running and the battery may run down quicker.
Either just use Run mode or go from there to Utility mode using the dash menus which the main difference is that it keeps the car from being driven away if the key is removed from the area. It's not ideal, but that's what it is,

 

As long as you're in the car, just leave it "on" and in park - you're using virtually no energy while not moving. It's not like an ICE car which would burn gas (and spew fumes) when idling. If you forget and try to leave the car before shutting it off, it will let you know.

 

Slight digression - during a particularly hot stretch this summer, we wanted to eat at an outdoor restaurant but we weren't allowed to have our dog at the tables, and of course we wouldn't normally leave her in a hot car. However, we realized we could leave the car - and the AC - turned "on" and the dog waited in a comfortable 70 degree F car. We had a lengthy dinner and it only took a few miles off the range!

The downside is I don't believe you can lock the car from outside while it is on, but it was parked in the lot where we could see it, and check on the dog. Oh and we needed to leave the key inside, or outside tucked under the wipers.

 

Yup, same reason, to run briefly some accessory (i.e. any system device).
But NOT for extended use as your EV has a small, light-duty 12v because it doesn't have to cold-crank an ICE. Hence the warnings..
Forget how you used it in previous cars, or you risk needing a tow truck. Power your system ON and use your big battery instead, no chance of it dying on you.
Your EV has an Accessory mode to make it familiar to owners coming from ICE cars, but it has very limited use...

 

I haven't tried it, but I found this post as a method to lock your car and leave AC running:

https://www.reddit.com/r/KonaEV/comments/cvlef4/testing_keyless_utility_mode_dog_mode_on_the_kona/

 

Quite possibly has just been carried over from the ICE Kona's.
You should also try out Utility mode - my manual states this is a good option for extended use of accessories, as it switches to power from the traction battery, and can be used for long periods...

 

I use this 'trick' all the time. Either when I stay in the car while wife is shopping, or she stay in the car while I get the beer. AS for with the dog...use the hidden key in the fob to close the doors.

 

I agree. The warning that running your battery will drain your 12V battery is crazy. If it is a real possibility they should have put a better, larger capacity 12V battery in the car.

 

I have no idea why they hide the "Utility" setting deep in the menu.

 

One of the biggest selling feature for an ev is RANGE. Anything done to lighten the vehicle means you don't have to burn electrons accelerating dead weight up to speed, leaving more capacity for the car's range. Thus you get a small (light) battery, no spare, and minimal sound insulation.