Battery preheating

The best advice I can give is to familiarize yourself with the app and preheating - and use it if the car is not plugged in. Battery preheating steals a few percent of the capacity and can delay the departure, but in return the batteries will give significantly better winter range.

Negative focus on winter range

Posted by Terje Bjørnstad
winter range
Don't be intimidated! You get far with an electric car in the cold.

When the winter cold sets in, the media are out with bold headlines. DinSide/Dagbladet has warned readers that the winter range may drop by half. In last year's cold test, the Tesla 3 ended up with only 53% of the stated range. Don't be intimidated!

 

No exact science

Official range figures (WLTP Combined) measure range under ideal conditions that are not affected by external circumstances. Out on the road, on the other hand, it is rare to achieve equally good ranges. It doesn't take more than a wet road surface before you notice it on the range. I have driven quite a few different electric cars. My experience is that real range under favorable conditions is about 4/5ths of the official figures, but that is before the "range thieves" appear. Cold steals range - but not as bad as Dinside/Dagbladet reports.

From Dinside/Dagbladet's test...

DinSide/Dagbladet tested the Tesla 3 together with other cars in 2020. The outside temperature was then "only" -9 degrees. During the first 10 kilometres, the heater, defroster and seat heater must have been used as normal. The average speed must have been 75 km/h. The 2020 edition of the Tesla 3 has a stated range of 560 km. The test revealed that the real winter range was only 301 km. Newer Tesla 3 delivered in 2021 is equipped with a heat pump. It gives better winter range. But the lack of a heat pump can hardly be the cause of the large loss of capacity.

Not normal

I often drive the Tesla Model 3 in the cold and can say with my hand on my heart that I have never experienced the same loss of range on long drives in the winter cold that DinSide/Dagbladet writes about. That is for sure possible but far from normal. The results, published in Dagbladet, give a tabloid impression of electric cars and the cold that electric car owners don't recognise.

A more nuanced picture

This week I measured consumption between Fornebu and Øyer - a stretch of around 20 miles that I drive often. I chose to drive National Highway 4 via Gjøvik, where the typical average speed is 75 km/h. The trip started in a heated garage. Between Nittedal and Øyer the temperature gradually dropped from -10 to -13. The average consumption in the last 50 km was 15.8 Kwh/100 km. Given the same consumption further up the valley, the calculated winter range would end up at a decent 443 km.

 

winter range
Tesla Model 3 comes to life in winter cold

Home Tour

Two days later I started the journey home in -19 degrees. The car was heated to 20 degrees with preheating of the batteries. You should preheat until the ice crystal symbol on the screen disappears. It is not switched off until the temperature inside the batteries reaches 19 degrees - which usually takes half an hour. I plotted Tesla's Supercharger on Øyer as the first destination. Then the batteries were automatically preheated before arrival. On Øyer, the outside temperature was -11 degrees. From 40 to 70% battery capacity, the car received a charge of 56 Kw after a few seconds. Not great - but normal when several cars are waiting for charging.

When I moved on, the average consumption was high – 26.1 Kwh/100 km. That worried me a bit. With such high consumption, the range would end at a measly 280 km - i.e. worse than what Dinside/Dagbladet achieved. The temperature stayed at -11 along highway 4 all the way to Nittedal. Consumption dropped to around 17.5 Kwh/100 km and ended up at 13.9 Kwh/100 km in the last 50 km. Calculated winter range was 401 km - completely in line with what I have experienced previously.

If I had finished the "test" after 50 km, I would have ended up at a calculated (not real) level like DinSide/Dagbladet. That would have given a false picture of the Tesla 3's winter range.

 

terjes carsUpdated 01.02.2022: - Don't be intimidated by the tabloid press, which last autumn published headlines based on DinSide/Dagbladet's previous tests. Motor.no has recently presented the results of a thorough winter test of the range of electric cars. They give an impression that electric car owners can more easily identify with, even though Motor's testers have probably driven far more economically than the rest of us. Read the test in Motor

 

The Range Thieves

As mentioned, calculating range is not an exact science. Why did I achieve a higher winter reach than DinSide/Dagbladet? After all, speed and temperatures coincided. Could Dagbladet's test have started before the battery had reached the correct working temperature? Was the total range calculated on the basis of the very first miles? In that case, I would get the same result, but it would not show real winter range long-distance driving. In any case, there are several other factors that can steal range. Here are the "range thieves":

Speed ​​and driving style

On the route between Oslo and Biri, you can choose between driving the E6 or national highway 4. The E6 consists of a motorway where you can drive much faster than on national highway 4. I have experienced that speeds between 100-120 km/h drain the batteries about as much as degrees Celsius. The combination of high speed and freezing temperatures will therefore drain the batteries at record speed!

Outside temperature

There is a direct correlation between outside temperature and range. Firstly, batteries lose capacity in the cold. In addition, the batteries take longer to receive a charge, which means that they are not supplied with regenerative energy while driving. Before you set off on a long trip, it is important to preheat the batteries. Check the options for preheating and start this from the app well in advance of departure. The pre-heating steals electricity, but you get it back on the trip.

Hyundai Ioniq Electric withstands Norwegian winters well!

Air conditioning

ioniq
Ventilation for the batteries in the Ioniq series 1.
In winter, I usually set the indoor temperature to 20 degrees. Previously, I turned down the heat in electric cars to 16-18 degrees, but have experienced that it did not give a measurably higher range compared to driving with a comfortable interior temperature. In addition, some cars – Renault Zoe, Nissan Leaf and Hyundai Ioniq (-2019) – use air from the passenger compartment/air conditioning system to heat the batteries. In the Tesla 3, the batteries are preheated when you heat the car via the Tesla app. I therefore do not rule out that it could be a win-win situation to have the same temperature in the cabin as the batteries need. But turning the indoor temperature up to 25 degrees is unlikely to have any positive effect. Then it might be better to have weak seat heating for those who like it.

Be and lead

On the way home, there was salt over Lygna and inwards towards Oslo. Salt provides a wet road surface that reduces range compared to dry winter roads. Sleet and snow reduce range even more.

Winter tires

If you ordered the Tesla 3 with studless winter tires (2020), you got the Nokian Hakkapelitta R3. This is one of the winter tires with the lowest rolling resistance. It still has more rolling resistance than the original summer tyres. Studded tires have higher rolling resistance than studless tires. Anyone who rides a bike with studded tires knows how they suck energy. My winter wheels are 18 inches. 19 inches looks better but gives higher rolling resistance. In a Tesla forum I saw that 19-inch summer tires gave an increased consumption of 2,3% compared to 18-inchers.

Tire pressure

In extreme winter cold the tire pressure can drop. After two days in 17-20 degrees below zero, the tire pressure on my car had dropped by 0,1 bar (2 psi). Often the tire pressure increases when the tires hit the road, so I figured I would get the tire pressure back on the trip. It didn't happen. The lost air had to be replenished. Some say that you should increase the air pressure in the winter tires compared to what the car manufacturer says. I've done that and may have gotten better range, but shortened the life of the tires. All in all no financial profit,

 

winter range
Early BMW i3 works in winter too

Conclusion

Measuring range on real roads can never be an exact science. Sometimes you wonder where the range went? That's just how it is. What amazes me is how much range disappears at high speeds. Cold, on the other hand, has never produced any negative experiences. I have driven several different electric cars in the winter cold - also cars with a low range. They have withstood the cold far better than I expected.
 
It is based on my own experiences not normally to have the range halved in degrees Celsius without there being other factors that steal range. The best advice I can give is to familiarize yourself with the app and preheating - and use it if the car is not plugged in. The pre-heating steals a few percent of the battery capacity and can delay the departure, but in return the batteries will give significantly better winter range.

 

Well advanced in -16 degrees. The night was going to get colder.

The winter crystal on Tesla's screen tells you that the battery does not have sufficient temperature to function properly.

Sources. The articles below are from Dagbladet and may be hidden behind a paywall.

DinSide/Dagbladet 2021 - That's how short electric cars go in the cold

DinSide/Dagbladet 2020 - These electric cars can handle the winter best

 

See

preheating tesla 3
How many kWh does the Tesla 3 lose in the blast cold?
Range, range…

 

How many kWh does the Tesla 3 lose in the blast cold?

Posted by Terje Bjørnstad
preheating tesla 3
Battery loss in the cold

Electric car owners in cold regions certainly have good access to electricity where they park. But what happens if you are visiting and have to leave the electric car overnight in the freezing cold without access to electricity?

 

Looking for the cold

It was reported -16 degrees, but already after Lillehammer I saw that the degrees crept down to -18. It looked promising for a cold test. In Gudbrandsdalen, temperatures can vary with local conditions. I was on my way to check the holiday home before the winter holidays. Thawing water pipes, turning on the heat, shoveling, putting up firewood, chasing away mice, as well as other necessary caretaker tasks. It takes time to fire up a house with an inside temperature of 4 degrees. The cold did not disappoint. During the evening and night, the outside temperature dropped to -24,9 degrees.

The cold steals kilowatt-hours

I parked the Tesla with 80% on the batteries after charging on Øyer. The remaining battery capacity decreased in line with the falling outside temperature, but stabilized at 73% when the thermometer stopped at -24 degrees. During the night, 7% of the batteries had evaporated in the cold - of Tesla's 75 kwh, this amounts to 5,25 kwh.

preheating the batteries
Cold degrees

Lightning-fast heating of the compartment

Ready to leave, I started heating the cabin by preheating the batteries at the same time as scraping the windows. Scraping wasn't really necessary. The car warmed up long before I expected - much faster than in modern petrol cars. After I had turned off the water in the laundry cellar, loaded the luggage into the car and locked the house, the car was wonderfully warm and ice-free. Almost 15 minutes had passed.

Just driving?

The heating had taken another 2% of the batteries. They were now down to 71%. In total, the night had cost 9% of the battery capacity (6,75 kwh). But I was a little too quick on my feet to get off. The app that heats up the car shows a battery symbol with an ice rose when it preheats the batteries. It switches off when the temperature in the batteries is 19 degrees. I preheated for 15 minutes. Ideally, I should have continued preheating until the battery symbol went out. Preheating the batteries is not only for comfort, but to make the best use of the remaining battery capacity. If the batteries are too cold, they will not accept charging from regenerative energy. It therefore pays to preheat the batteries even if the car is not plugged in. I could have preheated for maybe 30-60 minutes. All monners leave. 15-20 minutes drains maybe 2 percent of the batteries, but makes the batteries give more range when you start driving.

Preheating the batteries

The pre-heating in the Tesla 3 uses the electric motors to produce the heat. The heating of the batteries is water-based – coolant that passes through all the cells. The pre-heating does not drain more power from the batteries than quiet driving, so you can start the pre-heating in good time. When you come from petrol and diesel cars, you are set on getting off as soon as the routes are ice-free. But preheating electric cars does not generate any toxic gases or noise. You can optionally start pre-heating without the air conditioning - or low temperature in the passenger compartment and gradually turn up the heat to save the batteries.

preheating tesla
Tesla Supercharger on Øyer. -16 and wind made it colder than it looks.

Slow charging in the cold

Although the batteries had not reached ideal temperature, they worked fine from the first kilometer. Consumption was the same as the day before. After 1 mile of driving, I set my destination to a charging station to buy coffee and sausage - and test charging. Tesla preheats the batteries before arrival, which in my case was calculated for 10 minutes. The batteries thus received additional preheating to cope with the cold. But the batteries were probably not quite ready to receive electricity. It took a few minutes before charging started, and then with low power. Although I was the only customer at Tesla's Supercharger facility, the maximum charging power did not reach more than 27 Kw during my little lunch break. The day before, the batteries received 87 Kw. But I didn't really need much power, so when the break was over, I moved on.

No big increase in consumption

The experts warn against higher electricity consumption in the cold - up to 41% higher than in summer. My winter consumption on the section Oslo - Øyer this trip was 25% higher than the lowest record measurement from September last year - and about the same level as other measurements made in warmer temperatures under alternating driving and driving conditions. Nor did the trip up offer any surprises in terms of range. I don't know if it is of great importance, but I drive with a thick sweater and an indoor temperature between 19-20 degrees. It is possible T-shirt and 25 degrees could have given other experiences.

 

Don't forget to preheat the batteries in the cold!

 

thaw thirteen
Water vapor looks dramatic in the cold. From here The Tine plant at Tretten.

Tesla Owners Club Norway: Battery heating

See

Tesla Model 3 Long Range
terjes cars
Life with Tesla 3
Temperature control of electric car batteries
Active battery cooling?

 

Active cooling of the batteries?

Posted by Terje Bjørnstad
battery cooling
Cars dissected in the interest of consumers.

Did you know that the Nissan Leaf and Volkswagen e-Golf lack active cooling of the batteries? Nissan has put restrictions on fast charging. Volkswagen dampens engine power if you drive too hard. It does not matter which solution is chosen to control the temperature. Read why!

 

The quality that is rarely mentioned

Modern electric cars should have systems that control the temperature in the battery cells. It is important for performance, for the batteries to take a fast charge, for range and for the life of the batteries. The factory numbers only apply when the batteries are at the correct temperature. The batteries prefer the same room temperature as us humans. Not all electric car models have satisfactory solutions. We have tried to find out which solutions are used in the most popular models. It's no easy task, even for car geeks.

Reverse Engineering

Car manufacturers prefer to present the battery packs as black boxes. They are generally reticent to provide detailed information. Even simple questions such as "Who produced the battery cells?", can be deeply embedded. It will then be much more difficult to find out how excess heat is conducted from the batteries under load, or how efficiently heat can be supplied on cold days. Fortunately, there are actors who make a living by picking things apart to document how they do it really is constructed, – the unvarnished truth. Cars such as Tesla 3, BMW i3, Opel Ampera (Chevrolet Bolt) and Renault Zoe have already been dissected.

Passive or active cooling?

battery cooling
Tesla 3 is the benchmark.
Passive cooling cannot control the temperature in the batteries, but can capture and dissipate a good deal of heat through the metal in the battery case and surrounding air. Active air cooling can consist of something as banal as a thermostatically controlled fan. One liquid cooled system is far better, where the glycol mixture (coolant) is led in channels around the batteries. It is ideal if the temperature changes in the batteries can contribute to heating the passenger compartment via a heat exchanger. In the future, perhaps the battery cells will be mounted in thermally insulated boxes.

battery cooling
Tesla 3 with round battery cells (ebay.com).

Flat or round cells?

Worldwide, there are only a handful of manufacturers who supply the entire world with battery cells. The best known are LG Chem, SK Innovation and Samsung SDI in South Korea, BYD and CATL in China and Panasonic, originally Japan. The battery manufacturers only deliver celler and allows car manufacturers to build their own battery packs. The following types of battery cells are used:

Pouch cells

Almost all new battery packs today are based on flat cells wrapped in plastic - so-called pouch cells (also referred to as pocket cells or pouch cells). These can be stacked close together (but not for close) – and usually vertically.

Prismatic cells

Here, the cells are wrapped in more solid material, such as aluminium, which absorbs more heat than the plastic in the bag cells. The BMW i3 and Volkswagen e-Golf use this.

Round cells

Round cells are reminiscent of flashlight batteries. Used by Tesla, but Toyota uses/will use round cells as well. These can also absorb more heat than the bag cells.

 

Liquid cooling

Tesla 3

battery cooling
Cooling between the cells. Clippings from YouTube. See Jalopnik's YouTube feature at the bottom of the post.
Upright round/sleeve-shaped cells from Panasonic. Between the cell rows, coolant is led through channels in flat cooling belts at full height. The cooling tape is attached to each cell with a type of adhesive that conducts heat. Each cell is surrounded by cooling from two sides. The system consists of several loops to dissipate heat. In cool conditions, the system is used to heat the batteries.

Opel Ampera/Chevrolet Bolt

Vertical bag cells from LG Chem. Separate cooling frame under the batteries with coolant channels controls temperature. For reasons of space, the battery cells are stacked with two layers at the back - as an extra elevation. It is uncertain whether the topmost cells get as good cooling as the cells closest to the cooling frame.

Audi e-tron

e-tron battery cooling
Battery cooling (audi.com)
Vertical bag cells from LG Chem. A network of coolant channels under the batteries ensures that heat is transported away - or added heat if required. When cooling, the liquid passes through a cooling element. The car's radiator is used for heating. The system is connected to a heat pump. Audi claims that their cooling should be more efficient than Tesla's solution.

Jaguar I-Pace

Vertical bag cells from LG Chem. Liquid-cooled temperature control. Unknown how the channels run, but it is assumed that they are located under the battery pack and consist of several loops. Jaguar is reticent to publish detailed information.

Hyundai Kona

Bag cells from LG Chem. Active thermal management with liquid-cooled channels in a cooling plate under the batteries that transports away heat when needed. The system has several loops and its own cooler. The system can also produce heat when needed. NB! Only cars for the Nordic markets have a battery heater.

KIA e Niro

Bag cells from SK Innovation. Liquid cooling. Same system for thermal management of the batteries as the Hyundai Kona.

 

Models that have been upgraded from air to liquid cooling

Hyundai Ioniq

ioniq battery ventilation
Ventilation for the batteries in the Ioniq series 1.
Bag cells from LG Chem. Hyundai states that models from 2020 with a 38,3 kwh battery have liquid cooling. There is no information material on how the system is built, but it is assumed to be of the same type that the Hyundai Kona uses, - and which from 2020 will also be rolled out in the new KIA e-Soul. The outgoing model of the Ioniq, series 1 produced before 2020, has ventilation ducts from the passenger compartment with a thermostatically controlled fan that draws interior air towards the battery pack.

KIA e-Soul 64 kwh

Models from 2020+ have pouch cells from SK Innovation. Uses the same system for battery cooling and heating as the Hyundai Kona. The first series of KIA e-Soul – before 2020 – ventilates the batteries based on air from the car's air conditioning. They have their own fan to draw air if needed.

 

Active battery cooling with air

Renault Zoe

New 2020+ models with 52 kwh have vertical bag cells from LG Chem. All models (also older ones) have active air cooling that uses air from the car's air conditioning to supply cooled air directly into the battery box - one hole for intake and two for venting. During charging, the car can therefore start the air conditioning if necessary. The system can also use warm air from the heating system, for example during preheating.

BMW i3

battery cooling
BMW i3 battery pack (bmw.com)
Prismatic battery packs from Samsung are mounted over a frame with cooling channels. It is not air, but cooling gas that is sent out under the battery packs when needed. There are also heating wires that produce electrical heat under the batteries.

 

Without active battery cooling

Nissan Leaf

Lying pouch cells from Chinese AESCs. Nissan claims that there is no need for active battery cooling, even for 62 kw batteries. Leaf has put a limitation in the software to limit fast charging several times in a row - on the same day. The phenomenon is hashtagged #rapidgate. This is probably done to prevent damage to the battery due to a lack of active battery cooling. Cars that are delivered to cold regions have battery heaters that are primarily intended to protect the batteries from being destroyed in extreme cold - not to provide an optimal operating temperature.

Volkswagen e-Golf

Prism cells from Panasonic. Volkswagen claims that the batteries do not need an external source for battery cooling and heating. In addition to passive cooling, the e-Golfs have a function that automatically reduces the current when you press the gas too hard for a long time. It official the rationale is to reduce consumption. It real the rationale is likely to reduce the possibility of the battery overheating. Likewise, the charging power is limited if the battery is too hot. This is common on all electric cars, but is rarely a problem on cars with active battery cooling. Volkswagen has given a recommendation that the e-Golf should not be fast-charged more than every other charge.

Conclusion

It is not surprising that premium cars such as the Tesla 3 and Audi e-tron have proper temperature control of the battery cells. Although performance degradation has been demonstrated in the Tesla after repeated accelerations due to the battery cooling not being efficient enough. If it is not the world's best, it is a benchmark for the other electric cars.

I am impressed that even affordable electric cars have active, liquid-based cooling of the batteries. I'm thinking in particular of the new KIA e-Soul and Hyundai Ioniq. Mentions on the fly also the Renault Zoe passenger car with separate air ducts from the air conditioning directly into the battery box.

It's about what we get for our money. If you use an electric car in temperate environments with quiet charging, you can certainly save a few kroner by choosing a model without active battery cooling. The most important thing is that you make conscious choices.

The car manufacturers must then explain how they ensure that the battery cells reach the optimum working temperature. Please mention it in the brochures!

 

See

Jalopnik have visited Munro & Associates which has screwed three leading electric cars completely apart. Jalopnik characterizes the three cars as "conventional approach", "weirdo approach" and "blank sheet". Guess who is who!

tesla3 battery
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i3 battery
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