Charging the Niro EV 2023 in the winter as fast as summer

    We, Kia Niro EV owners, know that our car is not the slowest one for battery charging, but it's far from being the fastest. During summer, it's ok to wait like 45 minutes while we do a pause to eat something so we don't really waste time. But when we can't synchronize our pause with the car charging late at night on a Sunday and going back home, it's not fun to wait the charge in the car doing nothing useful.

    Now that we're passing our first winter with our Niro EV, we're not confortable to plan road trips with the car because, uh... I can't plan without knowing how the car will react in the cold! For sure the consumption is worse and I plan to do a short trip to measure the consumption, but what about the charging time?

    I don't have precise data about the charging time with the cold battery, but I saw that it's much slower that what I got during summer. Compare this post's charging curve that reaches up to 84kW during summer with these ones with 3 different cold temperatures. My guess is that close to 0°C/32°F, it would take like 1.5 to 2 hours to charge from 20% to 80% instead of around 45 minutes which is the official specification.

    That's really not good! So I started doing some research to find out ways to improve it and if it's possible to have a charging time as "fast" as the specification during cold times. I didn't find those answers at all for the Niro EV. So I started to do some experiments to try to find out the answer. Today I did another charging session and the answer is yes! The outside temperature was about 0°C/32°F and the car charged the battery from a S.O.C (State Of Charge) of 19% to 80% in 42 minutes, with is slightly better than the official specification (45 minutes from 20% to 80%). The charging time from 20% to 80% in this this post in hot weather was 38 minutes, which is not that far from what I got in winter.

    That's definitively good news, but there a lot of small details that are not published by Kia and some of them are not intuitive. So let's talk about them while describing how to do it.

First of all, you have to activate the battery conditioning feature in the infotainment otherwise it won't work.

Then, you have to put a DC charger as your destination in the car's navigation system. It doesn't work with any other navigation software like Google Maps, etc. If you start any GPS navigation on an app in your cellphone connected to the car with CarPlay or Android Auto, the car's navigation system will stop and the battery conditioning as well. Some people think that it's not feasible to find out the desired DC charger in the destination because the list is sorted by the distance from where we are. But if we click on the map close to the destination, the DC chargers will be sorted by the distance from the point you defined in the map. I recommend you guys to try it first at home before travelling. I had a hard time figuring out how to do it during by trip.

The charging power is limited accordingly to temperature of the coldest of the 5 battery modules. This is called cold gate. I read in this discussion that the thresholds for different power limits would be 1°C/34°F, 5°C/41°F, 15°C/59°C and 25°C/77°F. There's no way to see this temperature other than using a OBD2 scanner. I use the Veepeak OBDCheck BLE+ Bluetooth 4.0 OBD2 Scanner with the Car Scanner mobile app. When the outside temperature is close to 0°C/32°F, it takes around one hour to heat the battery up something close to 21°C/70°F and then the battery conditioning stops. I did it at home. Maybe it'll be less efficient with the car running and the cold wind passing under the car. The user manual says that the battery conditioning will be turned off if the battery charge is low, but it doesn't say which is the threshold. I suppose it is the same as Kia EV6 and Hyundai Ioniq 5 and 6, which is 20% of S.O.C.

Once the charging started, the battery temperature was still not in the 25°C/77°F required to have the same curve as the ideal one. But after some minutes, the charging causes the temperature to rise and once this required temperature is reached, the charge is as fast as it can be during summer temperatures.

In my experiments, the battery heater consumed something between 4 and 5kW. Since it takes 1 hour to heat the battery from 0°C/32°F, this will "burn" between 4 and 5kWh of the battery. This represents like 6 to 8% of the battery capacity. One way to avoid wasting this amount of energy is to post-pone the level 2 charging at home so that it finishes at 100% close to the departure time. The battery heater is used during the level 2 charging when it's cold. Heating the cabin is also a good idea so that the car will just maintain this temperature during the travel. Doing more frequent stops for charging will help maintaining the battery heat and thus, spending less energy with the battery conditioning.

This is the ideal charging curve that I found on the internet (blue) and the one that I had with the conditioned battery (orange). The curve for the conditioned battery started lower that the ideal one. Once the battery temperature reached 25°C/77°F around S.O.C. of 34%, the power increased drastically and got close to the same value as the ideal one. After that, the power steps were pretty close, but the curve of the conditioned battery was getting down to the next power step earlier that the ideal curve.

Start of battery conditioning.

End of battery conditioning.

Start of charge with 19% of S.O.C.

End of charge with 80% of S.O.C.

I'll try to repeat the experiment when we'll have more challenging temperature of the Canadian winter like -25°C/-13°F.