EVLN: Cold-weather heat pumps 2reduce EV pack range loss

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EVLN: Cold-weather heat pumps 2reduce EV pack range loss

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Can heat pumps solve cold-weather range loss for EVs?
August 8, 2019  Bengt Halvorson


Mahle Integrated Thermal System


2017 BMW i3 electric car during winter snow storm [photo: owner Chris Neff]

This past winter’s deep freeze and its record-low temperatures exposed a
reality that anyone thinking about an electric car has to come to terms
with: Cold winter weather can cut the effective driving range of some
electric vehicles by 40 percent or more.

Partly to blame is that the resistive heating electric cars rely on (yes,
like those glowing elements in your toaster) takes a lot of energy. But it’s
more than that, as the batteries themselves need to be warmed to be at their

The supplier Mahle is one of several companies looking at the cold-weather
problem comprehensively. Last month it announced what it calls the
Integrated Thermal System, which the company says could recover 20 percent
of the cold-weather loss.

That system is one of several developed by suppliers around heat-pump
technology and other thermal strategies, aiming to reduce the load on
resistive heating.

Heat pumps aid efficiency because they move heat rather than generate it.
Models with heat pumps typically use a reversible setup to transfer thermal
energy out of the cabin during hot weather (functioning as an
air-conditioning compressor), and to bring thermal energy from power
components or outside into the cabin in cold weather. According to Bosch, a
heat pump drawing 1 kw will generate the heat equivalent of between 2 and 3

Climate control systems still need the toaster bits and the traditional air
conditioning operation for quick heat or cooling when you get in the car,
but they help keep things comfortable over long commutes or road trips.

The 2013 Nissan Leaf was the first mass-produced vehicle in the world to
offer a heat-pump-based cabin heater; that system has helped extend driving
range during the winter months. All versions of the BMW i3 EV have offered
it, and the Jaguar I-Pace and Audi E-tron have a heat-pump system. So does
the Toyota Prius Prime, and most versions of the Volkswagen e-Golf.

Not all EVs have it. The Hyundai Kona Electric doesn’t come with a heat pump
while the Kia Niro EV does. Tesla models don’t use a heat pump as part of
the climate control system but do use waste heat from the motor and power
electronics to help warm the battery.

[image]  2019 Kia Niro EV first drive - Santa Cruz, CA - February 2019

The Mahle ITS incorporates several different components into a single system
that can help with heating and cooling, for both the cabin and power
systems. A chiller and condenser serve the functions of an evaporator and
condenser, while in between there’s a thermal expansion valve and at the
other end of the system, an electric drive compressor.

What makes it different is that it’s a neatly packaged, modular system that
“can be adapted to future vehicle architectures,” Mahle says, and a unified
alternative to what the supplier originally teased as a “holistic thermal
management” system in 2017.

With Tesla the one exception, perhaps, EVs that omit the heat pump in the
climate system generally do so to save cost. Climate control systems that
take full advantage of heat-pump systems increase the vehicle’s cost by a
few hundred dollars, we’ve been told, while resistive heat is cheap.

There’s another reason why many more vehicles don’t have it—especially in
the U.S. A heat pump system won’t raise official range estimates
significantly, if at all. Heating especially gets skipped over in the EPA’s
driving-cycle calculations for EVs. (There’s currently a hot-weather
air-conditioning cycle for gasoline and diesel vehicles).

The gains are significant, though. Visteon (now Hanon Systems) claimed some
years ago that in a New York City drive cycle, at 14 degrees, its fully
developed heat-pump-based system offers up to a 30 percent improvement in
driving range. And with a smart thermal management system that Bosch
introduced in 2015, it claimed 25 percent better range in wintry urban

To that, there’s some cost-benefit analysis to be done. Heat pumps don’t
solve the cold-weather range punch, but they do soften the blow. Spending on
a heat pump will save many kwh of energy, and that translates directly to
more miles of range (or less battery capacity needed)—meaning you recover
more miles per minute you’re fast charging.

For electric cars that are truly intended for use outside of California—and
ready for next year’s deep freeze—the tech is becoming harder to ignore.
[© greencarreports.com]

EV startup unveils new insane-looking electric car with ‘400 miles’ of range
Aug. 1st 2019  Human Horizons, a new China-based electric car startup, has
launched its new premium all-electric smart brand, HiPhi, and unveiled its
first car, the HiPhi 1, an insane-looking electric SUV with up to 400 miles
of range ...

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