Tesla Is Being Smashed By Its Rivals In One Weird Way
Even cheap Chinese rivals are kicking their ass.
A few weeks ago, hoards of Tesla owners in Chicago got stranded as the winter weather bit. Their batteries froze, their car’s ranges fell off a cliff, and Tesla Superchargers struggled to pump juice into them. We have known for a while that EVs can struggle in cold weather, but we may have just found out why Teslas suffer more than any of their rivals in frigid temperatures. You see, the Norwegian Automotive Federation (NAF) has just completed its 2024 winter range test, and the brand-spanking new Tesla Model 3 Highland had by far one of the biggest range drops! But what’s telling is the EVs that did the best. Let me explain.
Let’s start at the beginning; why do EVs have issues in cold weather?
Well, firstly, it takes a surprising amount of energy to keep the cabin warm, and this parasitic loss can drain the battery rapidly, robbing you of tens of miles of range. But even if you put up with a bone-shakingly cold driving experience, range and charge speeds would suffer. You see, the electrolyte in the middle of the battery, which the lithium ions have to pass through during discharging and changing, becomes more resistant to lithium ions as it gets cold and slows their progress from one side to the other. This effectively reduces the available charge in the battery and can severely limit the rate at which it can be charged. To solve this, EVs have thermal management systems which heat up the battery, but this robs away charge, just like heating the cabin. As such, making an EV function well in cold weather is not only about designing better, more temperature-resistant batteries but also a thermal management balancing act.
Okay, so what about the results of this winter range test?
The Tesla on test was the dual motor long-range variant of the new facelifted Model 3 Highland. This car’s WLTP range is a massive 390 miles (639 km), but it only managed 274 miles (441 km) of mostly city driving in -2 to -10 degrees Celsius (28.4 to 14 degrees Fahrenheit) conditions. That is a vast reduction in range of 31%, which was one of the highest proportional loss of range of any car tested. For some comparison, EVs from KIA, NIO, XPeng, BMW, and Lotus only lost 12%-14% of their official range in the same conditions. Even the super cheap BYD Dolphin fared far better than the Tesla, only losing around 20%.
So how has a car that is nearly £20,000 ($25,000) cheaper than the Tesla faired so much better?
Well, let’s compare them. The £50,000 Model 3 has 491 horsepower, 0–60 mph in 4.4 seconds, a 78.1 kWh lithium-ion battery pack using LG NMC cylindrical cells, 250 kW peak charge rate with 10% to 80% happening in only 27 minutes and a WLTP range of 391 miles. In comparison, the £30,000 BYD Dolphin is way more basic. It only has 201 horsepower and can only do 0–60 mph in 7.0 seconds. It has a smaller 62 kWh battery pack, but this time, it’s based on BYD’s prismatic LFP cells (BYD Blade Battery), giving it a WLTP of 265 miles. In the Dolphin, this battery pack’s charge rate is limited to 88 kW (it can charge much faster), meaning 10% to 80% charge happens in 41 minutes.
The big difference here is the battery packs, and their chemistry, design and optimisations explain the differences between the two and why Tesla lags behind in the winter range test.
LFP cells are much cheaper per kWh than lithium-ion cells, but are less energy-dense and take longer to charge. Cylindrical-shaped cells (which look like sized-up AA batteries) have a higher energy density than prismatic cells (which are rackable blade-like batteries). But prismatic battery packs are cheaper to produce, as they have far fewer parts and also have much better thermal properties (cools and heats more per unit energy). This is why the budget-conscious BYD Dolphin uses prismatic LFP, and the performance-focused (i.e. fast charging & long range) Tesla uses cylindrical lithium-ion.
But, LFP cells also have a much wider operating temperature of -20°C (-4°F) to as high as 60°C (140°F) compared to the operating temperature of lithium-ion of 0°C (32°F) to 45°C (113°F). In other words, LFP cells are way more efficient in cold temperatures. This means the Dolphin didn’t have to heat its battery pack anywhere near as much as the Tesla did. Moreover, thanks to the prismatic cell design, it takes less energy to heat the Dolphin’s battery pack than the Tesla’s. So it is no wonder the BYD did so much better than the Tesla.
But what about the other rivals like the Kia, BMW and Lotus? They have similar specs to the Model 3 and also use cylindrical lithium-ion packs.
Well, the difference here is the charge rate. These EVs either charge at a lower peak rate than the Tesla (the BMW i5 peak is 205 kW) but prioritise widening the charge curve (charging at a higher average rate) or, if they have higher peak charging than the Tesla, but use an 800 V battery architecture rather than the standard 400 V. This means these cars utilise lower currents during charging, which creates less heat. As such, they have less cooling demand for the battery during charging, allowing their thermal management systems to be optimised to work in a wide range of temperatures, meaning they can heat or cool the pack efficiently. Meanwhile, the reason Tesla can achieve high peak charge rates is because they push current during charging to the max, which creates a lot of heat, meaning the battery thermal management system has to be optimised to cool the pack for charging. This comes at the expense of its heating ability, meaning it really struggles to warm the battery efficiently in cold weather.
This might also explain why many of the Tesla drivers recently stranded in Chicago couldn’t charge. Reports stated that the cars struggled to precondition their battery, which is when the car’s battery is heated to optimum charge temperatures. In such cold weather, a thermal management system optimised for cooling might not be physically capable of increasing the temperature enough, meaning charging couldn’t start.
This is why I wouldn’t be surprised if the new base-spec Model 3s and Ys also suffer more than their rivals in cold weather, despite adopting prismatic LFP packs. They keep the nominal voltage low at 400V but still push these batteries to charge at their limit, meaning sky-high currents and a lot of heat. This means they require the same cooling-optimised and heating-compromised thermal management systems as the higher-spec cars.
So, if, like me, you live somewhere which gets mighty chilly during the winter months, the best EV for you might not be the most obvious one. No EV is perfect, and subtle design differences get amplified in these conditions. Moreover, the EV market is on the cusp of maturing, as many breakout technologies, such as prismatic LFP battery packs and 800 V architecture, are slowly becoming more mainstream. But many people don’t know the advantages and disadvantages of these different technologies. So take your time and do your research when deciding what EV to get, as Tesla’s aren’t always better.
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Sources: NAF, Notebook Check, EV Database, EV Database, Ecoflow, The Guardian, ELB, ABC, MSG, EV Database, EV DatabaseÂ