Power Consumption on Preheating

[geoffshep69]

Just doing some calculations to work out my combined mpg when factoring in electricity costs, and I was wondering what it costs me for 10 minutes of pre-heating each morning ? Can anyone tell me what power the system draws to run the electric heater in the car ? I have a vague recollection that it is in the range of 3-4 KW, but can anyone confirm ?

 

[maby]

The maximum power drain of the heater is about 4kW. It will reduce as the temperature in the vehicle increases, but I guess that on a cold morning it would be running close to full power for the full 10 minutes of pre-heat

 

[lazarette]

So, what's that. 4kw at 10p per kWh= 40p/6 = about 6.5p for 10 mins..

 

[maby]

Sounds about right...

 

[geoffshep69]

Thanks all, thats pretty much in line with what I thought, had estimated it to be about 6p for 10 mins. By running the preheating I can pretty much do my 26 mile commute (13 miles each way) on full EV, but if I don't preheat then I struggle to get more than 20 miles at the moment.

 

[maby]

Pre-heating is very good - at least if you have a dedicated 16A fast charger at home because that can (almost) keep up with the power demands of the pre-heater. It's a bit less clear if you are using the slower charging box that plugs into a 13A socket - that cannot meet the demand of the heater by a moderate margin and you will get in the car to find that your battery has lost a noticeable amount of charge - which could translate to lost EV range.

 

[anko]

It will reduce as the temperature in the vehicle increases, ...

Will it indeed? Never noticed this. And if you pre-heat for 30 minutes at moderate temperatures,, the car will turn into an oven. No signs of taking it a step down ....

 

[maby]

It will reduce as the temperature in the vehicle increases, ...

Will it indeed? Never noticed this. And if you pre-heat for 30 minutes at moderate temperatures,, the car will turn into an oven. No signs of taking it a step down ....

You are probably correct where pre-heating is concerned - mine still runs for a maximum of 10 minutes, so I cannot test, but it does seem that pre-heating ignores the thermostat setting. I was thinking more in terms of the behaviour of the electrical heater in general terms - that is controlled by the thermostat and will turn itself down once the cabin comes up to temperature.

 

[Claymore]

The maximum power drain of the heater is about 4kW. It will reduce as the temperature in the vehicle increases, but I guess that on a cold morning it would be running close to full power for the full 10 minutes of pre-heat

It doesn't. The heater runs on full power for the period selected.

JimB

 

[Kim]

Initially it draws 4.5 kW
but when the heating elements are hot, it "drops" down to 3.8 kW for the rest of the heating periode.
The charger can compensate a max. of 3.3 kW