Battery Conditioning Power Consumption

Laurie Forbes

Laurie Forbes

New Member
Have looked extensively but cannot find the answer to my question so hoping this forum can help. I am trying to determine how much electric power is consumed by the battery heater at v low temperatures, for example, at -30C. IOWs, how many KWhs are used when the car is parked and plugged in for an entire 24 hours?? I am referring here to power consumed by the battery heater alone and not power consumed to charge the battery or warm the cabin.

I understand the battery heater is rated at about 2 KW but, I assume it does not operate continuously and is only energized as needed to keep the battery temperature above a certain level (perhaps it cycles on & off similar to a furnace/thermostat).

Thanks for any info.... :)
 
I think @apu may know this better than myself but I don't think the Kona's battery heater operates at all when the car is simply parked, unlike a Bolt.

Irrespective of that detail, if you use one of the smartphone apps with an OBD2 dongle you could monitor the battery heater output. Or, use an energy monitor on the portable EVSE's power plug to measure kWh going in assuming the battery is prevented from charging.
 
Thanks Kiwi. I assumed the battery had to be kept above a minimum temperature to avoid freezing damage (as you mention, like a Bolt). Having now looked through the Hyundai Electric Vehicle System Overview manual, I see no mention of a requirement for charging for battery conditioning for a parked vehicle at low temperatures so it looks like you are correct in that. Seems odd though as I understand the Kona and Bolt use similar battery technology.
 
I hear my forum moniker being invoked :) Laurie the answer to you question is based on several variables so not really easy to answer but lets try.
First off very cold ambient temperature is less important than the actual measured battery pack temperature, meaning if you have a garage or shelter for your Kona in the winter use it. The battery is a relatively large thermal mass and it can take as long as overnight in -30C ambient to have a significant effect. The default battery pack temperature before the BMS starts to care is around -17C, although I have seen the pack drop as low as -20C in -30C ambient weather. At that temperature vehicle charging from DC sources and power output to drive motor will be severely reduced and its possible to see turtle mode engaged at a relatively higher SOC and high energy drain conditions. If you have winter mode engaged and your car is plugged in to a 240V EVSE the battery heater will keep the battery in the 0-10C range when parked. The supplied 120V EVSE cannot provide this service as the actual battery heater rating is closer to 3Kw and the BMS will wait until a very low temp (again around -17C) before it starts to cannibalize it own battery for heat energy. How long does that battery heater run to keep minimum temperature requirements depends how long the car is parked and how cold the pack is but generally overnight probably less than a hour. If its plugged into a 240V EVSE with winter mode on probably 2+ hours in severe cold.
 
apu said:
I hear my forum moniker being invoked :) Laurie the answer to you question is based on several variables so not really easy to answer but lets try.
First off very cold ambient temperature is less important than the actual measured battery pack temperature, meaning if you have a garage or shelter for your Kona in the winter use it. The battery is a relatively large thermal mass and it can take as long as overnight in -30C ambient to have a significant effect. The default battery pack temperature before the BMS starts to care is around -17C, although I have seen the pack drop as low as -20C in -30C ambient weather. At that temperature vehicle charging from DC sources and power output to drive motor will be severely reduced and its possible to see turtle mode engaged at a relatively higher SOC and high energy drain conditions. If you have winter mode engaged and your car is plugged in to a 240V EVSE the battery heater will keep the battery in the 0-10C range when parked. The supplied 120V EVSE cannot provide this service as the actual battery heater rating is closer to 3Kw and the BMS will wait until a very low temp (again around -17C) before it starts to cannibalize it own battery for heat energy. How long does that battery heater run to keep minimum temperature requirements depends how long the car is parked and how cold the pack is but generally overnight probably less than a hour. If its plugged into a 240V EVSE with winter mode on probably 2+ hours in severe cold.
Click to expand...

So, for those of us in the U.S. who didn't have a "winter mode" option on our Kona's...is there still some kind of BMS heating system? Temps in MA where I live frequently get into the -15° to -18° C range. I have an unheated garage that gets nearly as cold as the outdoors. I've never understood what I could do to soften the blow of hard cold temps on my car.
 
Thanks apu, now I have a pretty good idea of what to expect. It looks then that battery heating will consume in the range of 3 to 6 KWH/d when parked in cold weather.

I wonder though what happens if the car is not plugged in when the battery is low (so it can't self-heat). Will that damage the battery? One might think not as it appears there is no recommendation in the Electrical System manual to keep the vehicle plugged in during cold weather.
 
Jgood said:
So, for those of us in the U.S. who didn't have a "winter mode" option on our Kona's...is there still some kind of BMS heating system? Temps in MA where I live frequently get into the -15° to -18° C range. I have an unheated garage that gets nearly as cold as the outdoors. I've never understood what I could do to soften the blow of hard cold temps on my car.
Click to expand...
Without a "winter mode" suggest no battery heater so not really much you can do other than shelter your vehicle when it gets really cold. You will get some passive battery heating through the charging process and just driving.

Laurie Forbes said:
Thanks apu, now I have a pretty good idea of what to expect. It looks then that battery heating will consume in the range of 3 to 6 KWH/d when parked in cold weather.

I wonder though what happens if the car is not plugged in when the battery is low (so it can't self-heat). Will that damage the battery? One might think not as it appears there is no recommendation in the Electrical System manual to keep the vehicle plugged in during cold weather.
Click to expand...
It will self heat just enough to preserve itself if it gets cold enough even if not plugged in.
 
KiwiME said:
I think @apu may know this better than myself but I don't think the Kona's battery heater operates at all when the car is simply parked, unlike a Bolt.
Click to expand...

Found this in the manual (page H6):

"The high voltage battery warmer system operates when the charging connector is connected to the vehicle.

However, the high voltage warmer system may not operate when battery temperature drops below -35°C (-31°F)."

So, am still wondering what damage, if any, the battery suffers if it's not plugged and is depleted in low temperatures. The manual, as far as I can tell, is silent on the issue.
 
Laurie Forbes said:
Found this in the manual (page H6):

"The high voltage battery warmer system operates when the charging connector is connected to the vehicle.

However, the high voltage warmer system may not operate when battery temperature drops below -35°C (-31°F)."

So, am still wondering what damage, if any, the battery suffers if it's not plugged and is depleted in low temperatures. The manual, as far as I can tell, is silent on the issue.
Click to expand...
Good article on this here:
https://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures
Highlights state "plating of metallic lithium can occur on the anode during a sub freezing charge...this is permanent and cannot be removed with cycling... vulnerable to failure if exposed to vibration or other stressful conditions"
As far as cold discharging, the life cycle can be reduced :
discharge-voltage-temperature.jpg

https://batteryuniversity.com/learn/article/discharging_at_high_and_low_temperatures
As well try to avoid a large depth of discharge (DoD) which can reduce the cycle count (as much as possible):
https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
If you are in a situation where the battery is freezing condition and very low SOC, as apu suggests try to keep it in a sheltered place until the temperature rises to an tolerable ambient temperature, even if this requires towing to a heated garage (beats waiting for the next Chinook to blow in:)). Obviously it is imperative to keep an eye on the SOC in the winter, and plug in when not in use to initiate the "winter mode" heating. You will also find the internal resistance goes up in cold conditions so that small resistance will help heat the pack as well.
 
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Thank you eddy, even though the manual is not explicit on the matter, it looks like TLC at low temperatures will prolong battery life. I guess that's why the Bolt recommendations are to keep the vehicle plugged in when parked in low temperatures.

If however, for example, one expends a good amount of the battery driving to an airport and leaves it parked for a couple of weeks in -20 weather, things might not be great for the return trip.
 
Living in Qc with severed cold this winter, I closely watch the battery with evnotify. I found that even below -20C, the heater hasn't heat up the battery. Kona was plug to charge it till 80% morning, and didn't go below 35% with my transportation need.
Winter mode was not activated on my dash console. Now, from what I read and saw on youtube, the winter mode was really more useful with very low SOC.

So far, I hasn't activated it. Will try next year to switch it on and see if i really does something in my case.
 
EVPower said:
Living in Qc with severed cold this winter, I closely watch the battery with evnotify. I found that even below -20C, the heater hasn't heat up the battery. Kona was plug to charge it till 80% morning, and didn't go below 35% with my transportation need.
Winter mode was not activated on my dash console. Now, from what I read and saw on youtube, the winter mode was really more useful with very low SOC.

So far, I hasn't activated it. Will try next year to switch it on and see if i really does something in my case.
Click to expand...
Having it plugged into a 240V EVSE and having winter mode on will definitely keep the battery much warmer, plus winter mode activates the battery heater when you are DC charging and allows for much quicker DC charging when its really cold. When your paying for electricity by the minute you really notice.
 
Resurrecting this thread for a quick question. I'm in New England, where we get our share of
"Canadian" weather sometimes in winter, and of course being in the US we don't get the battery
heater. There are lots of horror stories, or at least scary theory, around charging a frozen lithium
battery, even a little bit. What are peoples' experiences trying to charge a "cold soaked" pack,
at either L2 or CCS rates, without being able to warm it first?

Thinking ahead a little, now that it's fall..

_H*
 
There is really no battery heater in US model?
I suspected that it is missing a heat pump, but not a classical PTC heater element for the battery.

Anyway, Kona has a NMC battery which can charge and be used also in quite cold weather.
More problematic are LFP batteries which have big issues with charging below freezeing point. Tesla uses those and i suspect it also heats them up.
 
I bought a 2022 Kona EV (SEL) a couple months ago in the US. It has a battery heater. The sticker that was on the car shows the heater was part of a convenience package that included other things like heated front seats, power sunroof, seat adjustments, etc. The software in the car also lets me turn Winter Mode on or off...another indication of a battery heater.
 
KevinH said:
I bought a 2022 Kona EV (SEL) a couple months ago in the US. It has a battery heater. The sticker that was on the car shows the heater was part of a convenience package that included other things like heated front seats, power sunroof, seat adjustments, etc. The software in the car also lets me turn Winter Mode on or off...another indication of a battery heater.
Click to expand...
If your cars software includes electricity usage info, under the battery care option, should provide when and how much energy is used for heating the pack.
 
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