The essential device every electric car should have - and why it makes a difference

Phones, laptops, WiFi - there are lots of things people can't live without. But there's another thing electric cars swear by.

And while this new technology has only been around for a number of years, it is now an essential function of the modern day EV.

Step forward, the heat pump. Here, we explain how heat pumps work, how they benefit your electric car, and how much they cost as an optional extra?

Why does an EV need a heat pump?

Motors, be it for an electric or combustion engine, produce heat when they operate. The heat energy created is often lost, but in a bid to put it to good use, combustion engine cars use a small amount of it to help run a car’s heating and ventilation systems. 

In contrast, electric cars offer a greater level of efficiency: while the motors and batteries do produce excess heat that can limit range, there isn’t enough to be used to power other systems like the heater. So in winter, EV drivers go cold, or are forced to draw extra power from the battery to operate a fan heater, which is far from ideal. 

What does a heat pump have in common with a fridge?

Think of a heat pump as a refrigerator, but in reverse: its function is the opposite of the one found in your kitchen. 

A household fridge contains refrigerant gas which becomes hot when compressed. Once compressed the gas is transported around a number of tubes to the condenser. 

The condenser then radiates the heat out, thus cooling the refrigerant gas which then travels into a grid called the evaporator. Because the evaporator is larger than the condenser, the pressure drops and the liquid refrigerant is evaporated. The temperature then drops and the fridge is cooled. 

How a heat pump works

In an EV, the heat pump draws air in from outside and compresses it, then uses the heat from the condenser to raise the temperature in either the battery or the car's interior.                                                                       

Reversible heat pumps can also warm, as well as cool, the battery. If cooling, any excess heat from the battery can be sent to the inside via the cabin heater. 

Does it increase the range of an EV?

Adding a heat pump brings a number of benefits, but most importantly is its ability to increase the range of your electric car, particularly in winter. When an EV is switched on in a colder environment, it takes longer for the battery to warm up which reduces efficiency. 

Does it increase the range of an EV?

The lithium-ion batteries in an EV rely on chemical reactions to store and create electricity; cold weather slows these reactions down resulting in the drop in performance and range. 

It is estimated that EVs range drops by around 10 per cent in winter, even before you account for using extra energy for cabin heating. Heat pumps can really help reduce that drop-off.

Is a heat pump really worth the extra cost?

If our winter real-world range test is anything to go by then you’ll definitely add a heat pump to your new EV. The electric cars fitted with a heat pump fell short of their official range by an average of 25.4 per cent, while those without suffered a 33.6 per cent deficit. 

Cars with heat pumps also proved more efficient, averaging 3.2 miles/kWh, compared with 2.9 miles/kWh for ones without. 

Are there any other benefits I should know about?

While a heat pump’s primary role is to boost range, most are programmed to be remotely controlled by your smartphone, allowing EV owners to heat their car before they set off on a journey. 

And if you’re plugged into the mains electricity, you won't drain the battery either. 

Do heat pumps come as standard?

With heat pumps becoming more commonplace, brand’s such as Tesla, Porsche and BMW offer its model with the device as standard. Some manufacturers, however, make buyers pay for the privilege, and frustratingly they can be a pricey addition. 

The Hyundai Ioniq 5, for example, offers a heat pump as an optional extra for £995. Skoda asks for £1025 for a heat pump for the Enyaq iV. It is worth noting that heat pumps are often included in the kit list for higher trim levels of many models.

Even if they are an expensive option, a heat pump is worth considering: they have extensive benefits, from improving efficiency, to increasing the range of your EV. 

Whether you’re thinking of making the switch to an EV or about to order your new set of zero-emission wheels, we’d recommend adding a heat pump for peace of mind.