The EV fact thread

[BTB 500]

Why would you want to include cabin pre-heating in the energy cost-per-mile calculation?

Because if you've used this it's an actual cost you've incurred for that trip. It saves you consuming power from the battery to heat the cabin up (and possibly warm the battery, depending on the vehicle and temp.) after you set off (which would be reflected in your on-board consumption).

 

[BTB 500]

No such thing AFAIK. Block heaters like they use in cold countries are about it.....and if course they use electric.

I guess they've died out now that modern engines heat up a lot quicker and HVAC typically has built-in electric heating, but quite a few Merc. models had the option of a diesel-powered auxiliary heater. Common on VW vans too. Never had one myself but I'm pretty sure you could set them to come on at a particular time to pre-warm the vehicle. Usually there's a vent for them in one front wing e.g.

 

[Steveml63]

Hi
Below is a screenshot from my TeslaFi app which gives very extensive data on your Tesla - including how much power you put into your car along with how much was consumed.
On Saturday, I purposely ran my battery down to a very low state of charge (2%) and then charged it fully to 100% on my home charger.
This allows the BMS (Battery Management System) the opportunity to recalibrate and after doing this each time (every 3 months or so) - you see the potential full range increase slightly (and therefore the percentage battery degradation since new is reduced slightly)
You can see from my screenshot that to charge from 2% to 100% on a 3-phase 11kw home wall box it took exactly 7 hours and 0 minutes.
It put 71.07kw/h into the battery but consumed 75.87kw/h from my home electricity supply (at an equivalent cost of $9.48 - converts to around 34.8 AED or £7.53 - this will give me around 460 km (285 miles) if I drive sensibly!
The conversion efficient is therefore shown as 93.7%.
I lost 4.8 kw/h in charging due to losses - which costs me around 30p
The bottom screenshot shows a DC fast charger session on a 250kw Supercharger at our local shopping mall - which is just a few minutes from our house.
This charged from 25% to 90% in 37 minutes with 97.7% efficiency - and in fact would have been quicker and more efficient if I lived further away from it - as the battery charges better if you navigate to the charger and the battery then gets pre-heated to the optimum temperature to accept the fastest charge.

Cheers
Steve

 

[SmartAmg]

Hi
Below is a screenshot from my TeslaFi app which gives very extensive data on your Tesla - including how much power you put into your car along with how much was consumed.
On Saturday, I purposely ran my battery down to a very low state of charge (2%) and then charged it fully to 100% on my home charger.
This allows the BMS (Battery Management System) the opportunity to recalibrate and after doing this each time (every 3 months or so) - you see the potential full range increase slightly (and therefore the percentage battery degradation since new is reduced slightly)
You can see from my screenshot that to charge from 2% to 100% on a 3-phase 11kw home wall box it took exactly 7 hours and 0 minutes.
It put 71.07kw/h into the battery but consumed 75.87kw/h from my home electricity supply (at an equivalent cost of $9.48 - converts to around 34.8 AED or £7.53 - this will give me around 460 km (285 miles) if I drive sensibly!
The conversion efficient is therefore shown as 93.7%.
I lost 4.8 kw/h in charging due to losses - which costs me around 30p
The bottom screenshot shows a DC fast charger session on a 250kw Supercharger at our local shopping mall - which is just a few minutes from our house.
This charged from 25% to 90% in 37 minutes with 97.7% efficiency - and in fact would have been quicker and more efficient if I lived further away from it - as the battery charges better if you navigate to the charger and the battery then gets pre-heated to the optimum temperature to accept the fastest charge.
View attachment 153481View attachment 153482
Cheers
Steve

That may aswell be in Chinese as far as I'm concerned.

 

[Mactech]

Hi
Below is a screenshot from my TeslaFi app which gives very extensive data on your Tesla - including how much power you put into your car along with how much was consumed.
On Saturday, I purposely ran my battery down to a very low state of charge (2%) and then charged it fully to 100% on my home charger.
This allows the BMS (Battery Management System) the opportunity to recalibrate and after doing this each time (every 3 months or so) - you see the potential full range increase slightly (and therefore the percentage battery degradation since new is reduced slightly)
You can see from my screenshot that to charge from 2% to 100% on a 3-phase 11kw home wall box it took exactly 7 hours and 0 minutes.
It put 71.07kw/h into the battery but consumed 75.87kw/h from my home electricity supply (at an equivalent cost of $9.48 - converts to around 34.8 AED or £7.53 - this will give me around 460 km (285 miles) if I drive sensibly!
The conversion efficient is therefore shown as 93.7%.
I lost 4.8 kw/h in charging due to losses - which costs me around 30p
The bottom screenshot shows a DC fast charger session on a 250kw Supercharger at our local shopping mall - which is just a few minutes from our house.
This charged from 25% to 90% in 37 minutes with 97.7% efficiency - and in fact would have been quicker and more efficient if I lived further away from it - as the battery charges better if you navigate to the charger and the battery then gets pre-heated to the optimum temperature to accept the fastest charge.
View attachment 153481View attachment 153482
Cheers
Steve

Yes, I understand the Tesla system is likely to be more advanced that the 'vintage' BMW one and that my home charging is at a much slower rate that you are charging at. However, the efficiency figures look a great deal closer to what I expect of the ones I can't accurately measure!

 

[ALFAitalia]

....and HVAC typically has built-in electric heating

Do they?.....not sure I've ever come across a car with that feature. Thought they all just relied on hot engine coolant for heating......Every day is a school day!

 

[Steveml63]

Do they?.....not sure I've ever come across a car with that feature. Thought they all just relied on hot engine coolant for heating......Every day is a school day!

Hi,
I worked in automotive electronics, diagnostics & fuel injection (for two different tier 1 suppliers) for nearly 20 years.
One of my diagnostic customers was Citroen and I often attended their dealer service training courses in their Slough UK HQ - when they introduced new technologies to their vehicles.
These included the first common rail diesel engines - the Citroen Xantia for instance had resistors in the water heating system to warm up the cabin temperature quicker. This is because the diesel engines were more efficient than petrol and therefore took longer to warm the coolant water.
Higher spec cars actually had a Webasto or maybe Eberspächer miniature diesel powered heater inside the front wing - like a little jet engine!
Cheers
Steve

 

[Mactech]

Hi,
I worked in automotive electronics, diagnostics & fuel injection (for two different tier 1 suppliers) for nearly 20 years.
One of my diagnostic customers was Citroen and I often attended their dealer service training courses in their Slough UK HQ - when they introduced new technologies to their vehicles.
These included the first common rail diesel engines - the Citroen Xantia for instance had resistors in the water heating system to warm up the cabin temperature quicker. This is because the diesel engines were more efficient than petrol and therefore took longer to warm the coolant water.
Higher spec cars actually had a Webasto or maybe Eberspächer miniature diesel powered heater inside the front wing - like a little jet engine!
Cheers
Steve

Yes, my V8 FFRR had one, but in keeping with the rest of the car, wasn't exactly reliable ....

 

[markjay]

Hi,
I worked in automotive electronics, diagnostics & fuel injection (for two different tier 1 suppliers) for nearly 20 years.
One of my diagnostic customers was Citroen and I often attended their dealer service training courses in their Slough UK HQ - when they introduced new technologies to their vehicles.
These included the first common rail diesel engines - the Citroen Xantia for instance had resistors in the water heating system to warm up the cabin temperature quicker. This is because the diesel engines were more efficient than petrol and therefore took longer to warm the coolant water.
Higher spec cars actually had a Webasto or maybe Eberspächer miniature diesel powered heater inside the front wing - like a little jet engine!
Cheers
Steve

The M270/M274 engine has an electric heater inside the thermostat housing.

 

[markjay]

Also, Thermotronic had a REST button on the climate control panel that allowed heat circulation inside the cabin with the engine switched off (e.g. when stopped for a break).

 

[Bobby Dazzler]

Also, Thermotronic had a REST button on the climate control panel that allowed heat circulation inside the cabin with the engine switched off (e.g. when stopped for a break).

REST is short for Restwärme (residual heat).

 

[BTB 500]

You can see from my screenshot that to charge from 2% to 100% on a 3-phase 11kw home wall box it took exactly 7 hours and 0 minutes.
It put 71.07kw/h into the battery but consumed 75.87kw/h from my home electricity supply (at an equivalent cost of $9.48 - converts to around 34.8 AED or £7.53 - this will give me around 460 km (285 miles) if I drive sensibly!
The conversion efficient is therefore shown as 93.7%.
I lost 4.8 kw/h in charging due to losses - which costs me around 30p
The bottom screenshot shows a DC fast charger session on a 250kw Supercharger at our local shopping mall - which is just a few minutes from our house.
This charged from 25% to 90% in 37 minutes with 97.7% efficiency - and in fact would have been quicker and more efficient if I lived further away from it - as the battery charges better if you navigate to the charger and the battery then gets pre-heated to the optimum temperature to accept the fastest charge.

Cheers
Steve

That's got to be one of the most confusing user interfaces I've ever seen! But it does explain where the incredibly low charging loss figures quoted from Tesla owner forums are coming from. If they're true then I'm very impressed. Total system losses as low as 2.3% seem inconceivable with DC charging currents of 400+ amps. Never mind the AC to DC conversion and powering the car's systems during charging.

As mentioned ADAC measured much higher loss figures in the independent testing they carried out in Germany

 

[BTB 500]

Yes, I understand the Tesla system is likely to be more advanced that the 'vintage' BMW one and that my home charging is at a much slower rate that you are charging at. However, the efficiency figures look a great deal closer to what I expect of the ones I can't accurately measure!

Very easy to validate if you're charging from a domestic mains socket - power meters that log kWh are cheap and easily available. Random example from Screwfix here:

Energenie ENER007 Energy Saving Power Meter Socket - Screwfix

Order online at Screwfix.com. Monitor and measure the energy use and costs of running household appliances. Simply plug into a powered mains socket and then plug any 13A rated appliance in. Discover which appliances use most energy, helping you lower power bills and reduce emissions. FREE next...

www.screwfix.com

But similar ones sold all over Amazon, eBay, etc. as well.

 

[BTB 500]

Do they?.....not sure I've ever come across a car with that feature. Thought they all just relied on hot engine coolant for heating......Every day is a school day!

Yep electric heating to speed demist etc. after a cold start has been quite common for years. My 17 year old Vito van has it.

 

[BTB 500]

Also, Thermotronic had a REST button on the climate control panel that allowed heat circulation inside the cabin with the engine switched off (e.g. when stopped for a break).

Even the manual aircon in our old Vito has this. But as mentioned it just uses the residual heat in the coolant system after a run.

 

[ALFAitalia]

Interesting... im amazed I've not come across it before.... even Google seems to know nothing apart from aftermarket add ons. The only thing I found was BMWs residual heat device that stored heat on an insulated ceramic container. It could stay warm a day or so to speed up cabin heating and demist.... but none that use electrical assistance.

 

[Steveml63]

That's got to be one of the most confusing user interfaces I've ever seen! But it does explain where the incredibly low charging loss figures quoted from Tesla owner forums are coming from. If they're true then I'm very impressed. Total system losses as low as 2.3% seem inconceivable with DC charging currents of 400+ amps. Never mind the AC to DC conversion and powering the car's systems during charging.

As mentioned ADAC measured much higher loss figures in the independent testing they carried out in Germany

The TeslaFi is a third party app that has permission to access all the data from your Tesla via an API.
It has multiple screens that give you numerous data about your car including battery health, charge stats, software updates etc.
There are other apps that also do similar things.
There is also a comprehensive service & diagnostic menu within the Tesla car itself - that technicians (and owners) can access to interrogate all the systems on the car and do very comprehensive self diagnostic checks - with a report that you can pass on to Tesla service if there is a problem detected.
Whatever you say about Tesla - it’s refreshing for a car owner to have so much free access to diagnostic data & information on their own vehicle - rather than the stonewalling you get from legacy automakers and the costs associated with getting faults diagnosed and then repaired!
This is coming from somebody that worked for a company that supplied the dealer diagnostic tools to many leading auto manufacturers for 15 years of my automotive working life!
Cheers
Steve

 

[Mactech]

Very easy to validate if you're charging from a domestic mains socket - power meters that log kWh are cheap and easily available. Random example from Screwfix here:

View attachment 153498

Energenie ENER007 Energy Saving Power Meter Socket - Screwfix

Order online at Screwfix.com. Monitor and measure the energy use and costs of running household appliances. Simply plug into a powered mains socket and then plug any 13A rated appliance in. Discover which appliances use most energy, helping you lower power bills and reduce emissions. FREE next...

www.screwfix.com

But similar ones sold all over Amazon, eBay, etc. as well.

I'd been looking for a smart plug with the capacity of over 2400 watts to turn on car charging with my phone when the sun shines.
I have now found one under the guise of a 'monitoring socket' with the capacity I need, will switch remotely and monitor consumption.
Might give this a try.

https://www.amazon.co.uk/gp/aw/d/B0CGC6235V/?_encoding=UTF8&pd_rd_plhdr=t&aaxitk=8b2b1aa41b4b0be6a01bb6ce574e5aed&hsa_cr_id=0&qid=1708411762&sr=1-2-e0fa1fdd-d857-4087-adda-5bd576b25987&ref_=sbx_be_s_sparkle_mcd_asin_1_title&pd_rd_w=eKx9t&content-id=amzn1.sym.25f7c301-a223-4ff8-91c9-accfeab9fda8%3Aamzn1.sym.25f7c301-a223-4ff8-91c9-accfeab9fda8&pf_rd_p=25f7c301-a223-4ff8-91c9-accfeab9fda8&pf_rd_r=CKW7XQQE9KF9NVN6PN48&pd_rd_wg=Q1KkH&pd_rd_r=aebbf4d0-7166-4e93-b865-3d67b2a8aec7&th=1

 

[Mactech]

That's got to be one of the most confusing user interfaces I've ever seen! But it does explain where the incredibly low charging loss figures quoted from Tesla owner forums are coming from. If they're true then I'm very impressed. Total system losses as low as 2.3% seem inconceivable with DC charging currents of 400+ amps. Never mind the AC to DC conversion and powering the car's systems during charging.

As mentioned ADAC measured much higher loss figures in the independent testing they carried out in Germany

As this an EV thread I'm not sure we would want to look at the energy losses in fuel for an ICE vehicle as it makes its way half way around the world, through various processes, multiple transport links, etc.....
But I'm quite sure the conversion from Norfolk sunshine to actual EV motion will be just a smidge more efficient....

 

[markjay]

Even the manual aircon in our old Vito has this. But as mentioned it just uses the residual heat in the coolant system after a run.

The heat will be residual, though the circulation will use electricity from the 12v battery (=fuel)