The BMW i3 Auxiliary Cabin Heating System (What You Need To Know)

There has been a lot of talk in the news about the BMW i3 being discontinued. It arrived in the 2014 model year with very few believing that it had the wherewithal and appeal to last as long as it did with the 200,000th unit rolling off the production line in late 2020. Now BMW plans to discontinue the i3 as soon as the i4 is ready for launch.

What does this mean? Whenever a car is discontinued from production, several things become true:

  • All future BMW i3 purchases will be pre-owned
  • BMW i3-specific components may become more expensive over time
  • Stock of BMW i3 cars will be forever limited to whatever is still roadworthy

With buyers increasingly turning to the pre-owned market for their i3 as the new-model market steadily dries up, one thing people will be looking out for is the BMW i3 “auxiliary cabin heating system.” It’s a longer name for something that we more often simply call a heat pump.

The BMW i3 has been a popular seller in cold climates since it is well engineered to work well in wintry weather. Where other EV producers have struggled with the meaning of harsh winters, their batteries and range suffering as the temperature outside plummets, BMW used their keen knowledge of “real winters” and made an EV that bears the winter better. The car’s popularity in colder countries like Norway, Sweden and the US (at least parts of the US) has made the heat pump something of a dealbreaker.

What is the Auxiliary Cabin Heating System? (Heat Pump)

BMW i3 white interior of cabin
BMW i3 white interior of cabin

Heat pumps are an innovative system of both heating and cooling that are becoming a growing trend in electric vehicles in particular. The primary concern with operating any EV is how much of your precious car battery life is being eaten up by every little thing you do in the car.

Before the innovation of the automotive heat pump, electric cars would just use ordinary resistance heaters to generate warmth in the car. Internal-combustion engines don’t have this problem of course because the warmth generated by such an engine gives you all the heat source that you need. What would emissions-free electric cars do? The answer was resistance heaters.

Later, cars started adding in these new devices known as heat pumps, brilliant not just because the consume something like 30 percent less power from the car than resistance heaters, but also that they can be used both for heating and cooling.

In heating mode, the heat pump system’s compressor drives refrigerant to the condenser, but unlike during cooling mode this time it happens in the opposite direction and heads through the evaporator. As the refrigerant goes through the expansion valve, it cools and thus can collect heat from outside the car. It then returns to the compressor warmer and then gets hotter within the compressor. After that, the heat is simply pumped into the car by way of the interior condenser.

Which BMW i3 Cars Had a Heat Pump?

Anyone living in a climate where having an effective car heater feels like a matter of life and death will take a heat pump seriously, especially in an electric car (more below). Residents of Sweden were fortunate in that every single BMW i3 BEV sold in that country did come with a heat pump. In other countries it wasn’t the same.

Among the all-electric BMW i3 models, in the US at least, all units made before the 2019 model year came with a heat pump as standard. In 2019, it became an optional thing. There is a simple way to check if a BMW i3 that you are interested in has a heat pump or not.

If you go to and input the vehicle’s VIN number, it will give you a full list of the equipment on that particular model.

BMW i3 VIN decoder
BMW i3 VIN decoder

If the heat pump is there, then it will always be listed, without exception. What you should find is that any model made before 2019 has the heat pump listed.

If you are looking at an i3 that was made for the 2019 model year or after, then you’ll have to go through the equipment list and make sure it’s there. Once again, if the heat pump is there, on any model, it is listed among the standard equipment. If you’re not sure, you can check for both “auxiliary cabin heating system” and “heat pump.”

BMW i3 REx

Besides the all-electric BMW i3, there was an alternative for those who were suffering from “range anxiety,” and that was the i3 REx, the latter part of which stands for ‘Range Extender.’ The idea of this model was to add a backup engine of 647cc in size. When the battery depleted to a certain level, the engine would kick in and help extend the battery life enough to get you to a charging station or possibly the last part of your journey home.

The REx version was never meant to be used in long-range situations, but those in colder climates found that it had a bigger problem than that. No version of the BMW i3 REx comes with the auxiliary cabin heating system. The reason for this is that the addition of the engine forces the rearranging of other parts, which ultimately left no space for the heat pump system.

The REx has been very popular in the US and Japan where demand for the extra range has been welcomed. In Europe, on the other hand, it wasn’t as popular. One reason for that was the absence of the air pump. As it turns out, drivers in northern Germany, Denmark, the UK and others weren’t interested in driving at greater range if it meant no efficient heat pump to save battery.

Conclusion: Why Do People Value a Heat Pump?

So now you know how to find out if a pre-owned BMW i3 is in possession of the auxiliary cabin heating system. The final question is why so many people really would care? In sum, these are the reasons people value that heat pump in their i3:

  • It saves 30 percent energy consumption compared to resistance heating
  • It can be used both as a heating and a cooling system
  • It’s does its job effectively and is ideal for colder climates

If you’re looking for a BMW i3, and your local area experiences cold winter, then we recommend checking to make sure the mode you are purchasing has the heat pump in the first place. Steer well clear of the REx models, too.

4 thoughts on “The BMW i3 Auxiliary Cabin Heating System (What You Need To Know)”

  1. Very useful information – I have a i3 Rex & have been struggling to find out how to use the heating system……..I now know why!

  2. Your comments on the i3 are really interesting, I am however also interested if any REx versions have had a heat pump retro fitted or if it is possible? There are possibly many others like me and Ron that are facing this during this cold snap.

  3. I have a 2014 i3 Rex. It has a preconditioning system. I set a timer on the dash and it heats the cabin. I’m not sure if it heats the battery.

  4. Also found this article very informative! Thank you. I am the proud new owner of a 2019 i3 that is otherwise loaded with everything. Including the REx…Sounds like jackets and heated seats for us in the cold months of Seattle.


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