During the cold winter, the electric car has advantages and disadvantages, and the biggest unknown is related to how much influence the autonomy cold. I monitored for 3 days a frosty autonomy BMW i3 without having to recharge it, and I came to the following conclusions.
At what temperature battery is affected?
What I mean by that is that the autonomy of electric cars begin to be significantly affected by cold starting temperatures of -5 degrees Celsius. Until there everything falls into some reasonable limits: consumption is higher, but not double or more than double the battery lasts less heating, the temperature change in the car (air conditioning) by 1-2 degrees plus or minus not "kill "too much battery.
Battery can have full autonomy about 170 km for the BMW i3 with big battery (94 Ah, 33 kWh), in a context where temperatures are within -5 degrees Celsius (the lower figure). As the temperature drops to -12 degrees Celsius, autonomy can reach 140 km or less. I have to refer more to -5 degrees Celsius, more common in "Russian winters."
Just because it is cold autonomy decreases from about 240 km (summer) to 195 km (winter). Without heat. When you start and heat (which is perfectly normal and recommended) is also going 25 km of autonomy.
Climate set to 22 degrees Celsius, AUTO, no A / C. Depending on when the temperature change in the car (ie if you have got some time to go by car or not), increasing temperature by 1 degree in the cockpit can mean decreasing autonomy 3 to 8 km. More details about this last point, the observations devoted exclusively to the heating system.
And loading is difficult at temperatures below -7 degrees Celsius. The car can draw from a power outlet (50 kW DC) about 0.25 kW / minute under these conditions. If the ambient temperature is higher (somewhere over -5 degrees Celsius), the car can hold about 0.6 kW / minute.
The idea is that just because it's cold load is 2.5 times slower than other seasons in which the ambient temperature is higher.
Chapter autonomy stick with that "real 170 km" I was talking about at first. A reasonable value as possible, I say. Obviously, this autonomy varies from machine to machine (now speak i3, the Renault Zoe will be another value, the Tesla Model S will be another value), depending on battery capacity, the average consumption of the car, and mass, not least, on driving style. If you pardon a summary of illiterate for i3 94Ah "-45 km to -25 km as cold and for heating, ie -70 km for the winter."
A short distance means more consume
It's not uncommon to have a consumer a little more than 30 kWh / 100 km if you travel far less than 5 kilometers. At each stop cabin loses heat, so by opening the doors, and the fact that the car is stationary and unheated Not started a certain number of minutes or hours.
In the first 1-2 kilometers consumer can have even 50-60 kWh / 100 km. It's a lot, but it should not scare you. It's normal. And car petrol and diesel everything happens so. Winter short distances, consumption may even be double or triple.
But unlike an electric car, the cabin is heated using a heat (energy) that would otherwise be lost. At each electric car "touch of heat" is obtained from the battery, not a "hot iron" under the hood.
Returning to the consumer at temperatures below -5 degrees Celsius is very hard to get in the city, averaging below 25 kWh / 100 km, and most often you will see on board an average consumption of about 30 kWh / 100 km . Spring, summer or fall you can get the same car under 15 kWh / 100 km in the city - so consumption halved.
Finally, even a consumption of 30 kWh / 100 km, this means moving money 3 euros / 100 km. So worth the cost per kilometer unbeatable.
The battery heats hard and cools hard
Unlike a fossil fuel engine, electric motor warming is irrelevant and uninteresting. Furthermore I am interested in battery, so that it suffers when it's cold. A gasoline or diesel warms few kilometers and minutes, maximum 15. It depends on many factors, such as how it is designed thermostat, engine capacity, fuel type. And many others.
In any case, you do not have to drive an hour or more to warm up your engine! At an electric BMW i3 in my case, if not even an hour drive, you run the battery all the time cold (read "under operating temperature"). The downside is that you never know what temperature does the battery is not displayed on anywhere.
Led by "at least an hour" I do not mean the traffic lights stood still in Bucharest. Talk of high energy (departures in place) and serious energy recovery (regenerative deceleration at least by 60 km / h to 0 km / h). Downloading and uploading large amounts of heat energy battery faster.
If you stand 5 minutes per place every traffic light is very clear as you go, always winter cold battery. Things change dramatically for the better if you heated garage or if you stay in there a complex of blocks and get parking in the basement (-2 or -3), where temperatures are positive. You will leave with battery warmer and it will remain so while driving (even warms and more).
The battery is cooled after several hours downtime of the machine, where it is left at low temperatures (Celsius values that I mentioned above). As I said, the battery heats and cools hard hard.
Preconditioning is essential if you want to go through without emotion for great distances
Preconditioning means, simply, the technical process by which batteries and interior are brought to the optimum temperature using direct current from the socket, not the battery, thus extending autonomy.
So avoid running the battery is already cold and heated cabin. All using current from the socket. Preconditioning is energy-intensive and time. If you set the schedule time of departure and to precondition the car, (pre) heating the battery will take 3 hours. The machine must necessarily be connected to an outlet for preconditioning be done and how is stronger socket, the better.
For maximum comfort physically and mentally access to an outlet overnight is ideal. But it can be without. I am not so, park the car on the block every time and upload shopping centers that have sockets quick (22 kW or 50 kW). On average, winter recharge every three days car use exclusively in Bucharest.
Over nights cold (-15 degrees Celsius minimum) battery charge level does not drop. So leave your car battery with 52.5%, and so on will be the next morning. The difference might be, but autonomy.
If the night was colder morning than autonomy displayed on reboot will be higher a few kilometers (even if the battery has remained the same load as a percentage%). And vice versa. If the next day is colder than the night autonomy displayed on reboot will be less.
It is also worth to remember that immediately after you put in motion in the first kilometers, the charge will decrease more than the distance traveled (eat 5 km autonomy 1 km traveled actually say) just because in the first kilometers after the restart consumption is very big. As you drive more (over 5 km), the range will "sit".
How about demisting and changing climatic comfort?
A very good thing is that the BMW i3 instant updates autonomy according to current customers. Heat start, -25 km range (when you have full battery). Heat stop, 25 km autonomy. Start heated seats, -1 km autonomy. You stop, 1 kilometers autonomy.
These calculations made instantly and accurately shows you the distance you can browse the car with very good accuracy.
Said about the heat and the 25 km "eat" ... Do not imagine that if you have autonomy stop 5 km and 30 km warmth you get autonomy. The machine calculates the heat consumption and potential savings brought it off depending on the battery charge and depending on the actual time remaining led to depletion of battery power.
So when you autonomy 5 km off heat as possible to bring you extra just 1 km. It's a bit complicated to understand, it took something until we understand how it works and how calculated. Returning to the precision with which BMW i3 calculates remaining battery charge calculations are scenarios where the car go crazy.
Let's say you have a session led by Bucharest that lasts 30 minutes. If you start with 22 degrees Celsius set to air conditioning installation, a few minutes later grow to 23 or 24 degrees, then dropped to 20 to 21 degrees ... Autonomy display goes awry +/- 10 km and recovers only when, for some kilometers and minutes, keep your fingers away from air conditioning.
That is why it is better to let 22 to 23 degrees Celsius in winter car, AUTO, no A / C. And do not touch the air conditioning installation until spring! So you maximum efficiency and precise calculations trip computer.
Sometimes, though, you need to start windscreen demisting. That can "eat" even 15 km of autonomy and demisting off after two minutes you will not return to baseline autonomy. It's a little strange.
Furthermore, if you restart again windscreen demisting autonomy will increase compared to the earlier time (though you have just restarted a major consumer). As I said ... you put your fingers in car air conditioning installation and calculations go wrong. Or stay in your bank and everything's fine.
Changing values in board autonomy with so many kilometers can be annoying and better keep your hands at home. Rear window defroster has no effect on autonomy. Just headlights, courtesy, audio, power windows. All have an insignificant impact.
Heated seats (regardless of stage and whether heated seats both or just one) influences range with only 1 km. There are 3 steps of heating for each of the two front seats.
Formula ideal, in my view, is the air conditioning on 22 degrees, AUTO (ie automatic distribution of airflow - legs, chest, head - according to information from sensors) without A / C (almost useless in winter useful only when they are very misted windows), heated seat on continuously while driving.
That said, it's good to know that in case of a BMW i3 autonomy in winter drops to about half, and recharging is difficult to negative temperatures. On the other hand windows thaws very quickly (1-2 minutes), the machine is immediately warm (up to 5 minutes) and do not have any emotions with engine start and noises it (as happens in cars fossil fuel).
