Star63
Posts: 12
Joined: Mon Sep 10, 2018 12:05 pm
Location: Finland

Installation of an auxiliary heater to improve electric range

Tue Feb 12, 2019 11:54 am

We've had a fairly cold winter this year in Finland. Even in the southern part of our country the temperature has occasionally been -25 deg Celsius. This has resulted in clearly reduced range and I found myself putting more clothes on when trying to minimize the need for the electric heating.

I finally decided to install a fuel burning auxiliary device to heat up the water in the heater loop.
This Eberspacher unit is located behind the frunk box:

Image

It could burn ethanol which would be more sustainable. I use fuel oil (diesel) instead because I think it is safer.

Image

The operating switch:

Image

I can use this heater instead of eletric heating while driving and I don't have to lower the temperature anymore to save electricity.
I can even pre-heat the car using the connected drive app. The fuel heater takes a signal from the original water circulation pump. The electric heater also kicks in but the PTC resistor will soon turn down the power consumption when the auxiliary device heats up the water.

It seems that the electric range is now about 30% longer. Very happy 8-)
Last edited by Star63 on Tue Mar 19, 2019 6:19 am, edited 1 time in total.
2014 BMW i3 REX

alohart
Posts: 1613
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Installation of an auxiliary heater to improve electric range

Tue Feb 12, 2019 5:49 pm

Mitsubishi i-MiEV owners who live in cold climates also installed auxiliary heaters powered by diesel or alcohol. By their accounts, this worked very well and did not burn much fuel.

I've been surprised that an auxiliary heater hasn't been an option in early EV's with limited battery pack capacity. This makes so much sense rather than using limited battery pack energy to heat the cabin.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

Star63
Posts: 12
Joined: Mon Sep 10, 2018 12:05 pm
Location: Finland

Re: Installation of an auxiliary heater to improve electric range

Wed Feb 13, 2019 2:15 am

An interesting thread on i-MiEV forum. I had not noticed that before. Thanks!
2014 BMW i3 REX

JohnKelly
Posts: 39
Joined: Sat Oct 07, 2017 7:02 am

Re: Installation of an auxiliary heater to improve electric range

Wed Feb 13, 2019 1:49 pm

The old air-cooled VWs used gas powered auxiliary heaters like that.... it was an option. A friend had it in his VW Thing and it worked extremely well. I think of my Rex as a gas heater... as the need for heat on our 65~mile round trips for groceries etc is main reason I have one. The secondary reason is more flexibility for planning longer trips.
2015 REX / Participating on plugshare w/level 2 Clipper Creek 32 amp, Moclips, Washington coast

Joff
Posts: 12
Joined: Wed Jan 02, 2019 2:44 am

Re: Installation of an auxiliary heater to improve electric range

Sun Mar 17, 2019 4:10 pm

Great solution! Is there separate pumps for interior heating and battery thermal management? have you checked the battery temperature, to make sure it does not get too warm? Inspirational post!

tjburbach
Posts: 39
Joined: Fri Oct 13, 2017 7:28 am
Location: Austin, TX

Re: Installation of an auxiliary heater to improve electric range

Mon Mar 18, 2019 7:53 am

The battery is heated using electrical resistance heating elements and cooled using a refrigerant loop from the A/C system. This water loop is only for cabin heating . It connects the cabin restive heater and the optional heat-pump to the cabin heater core.

AndrewDebbie
Posts: 152
Joined: Sun Aug 04, 2013 10:37 am
Location: Anglesey, Wales, UK

Re: Installation of an auxiliary heater to improve electric range

Mon Mar 18, 2019 8:07 am

alohart wrote:
I've been surprised that an auxiliary heater hasn't been an option in early EV's with limited battery pack capacity. This makes so much sense rather than using limited battery pack energy to heat the cabin.
A diesel air-fuel heater is a factory option on the Renault Kangoo Z.E. van.


British Gas retrofitted Eberspacher heaters on their fleet of 24kWh Nissan eNV200 vans. The BG vans are showing up on the used market now. I thought about getting one but decided the asking prices were too high.
2014 LEAF 24 (gone)
2017 LEAF 30 (gone)
2018 Mazda 2 (Debbie's)
2018 i3s 94Ah Rex

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