47 minutes ago, Rooted said:

My MINI Electric has a battery size of 32.6 kWh,  usable capacity 28.9 kWh.

100% charged pretty much shows 100 mile range, like this morning it was 101 miles at 0*oC, and AC on and Heating at 20*oC just 85 miles.

It does more than 100 miles and at worse so far maybe just 90 miles but that is Motorway speeds.

 

Anyway i have noticed that charging from 50% / 50 miles range to 100% is taking about 18kWh on the 3 pin charger at home and a max 10 amp setting.

15% - 100% has needed 28 kWh. 

 

On a Rapid / 50 kW charger it is a few kWh less, sometimes 40% to 100% is 18 kWh. Ambient temps are warmer though and i arrive with a hot battery.

Charging on the 3 pin lead at home the car is not arriving from been driven. 

(Sitting charging many hours, 12-15 sometimes.)

 

So almost empty to 100% / 100 -110 miles charging at home @ 21 pence a kWh might well need 30 kWh. so £6.30

 

I will see what things are like in the next couple of days with temps around 0*oC. 

 

So is the granny cable quite efficient ie close to 90% then ?

 

My Pod Point is only a 3.6 kw one, I was being a bit tight and save £100 rather than going for the 7.2 kW version so it only cost me £449. 

Granny cable was £129 or so I recall. Works at 10A, 220/240v.

 

Both seem fine in terms of efficiency, close enough to 90% to not really bother but yes alway worth noting that one pays for 100% of the energy used at home or public charger but "only" about 90% gets in to the battery as stored charge with the other 10% being waste heat but a little bit of humming as noise.

Still way better than a 35% ICE at converting chemical energy in to motion.

 

 

 

 

 

 

I didn't think it was anywhere near as high as 35%, maybe at the flywheel under wide open throttle at peak torque but far less during normal driving conditions, then there are all the further transmission losses before the energy arrives at the delivery point, the wheels, losses which I believe EVs do not suffer.

 

I admit at present I know nothing about EV power transmission, I'm assuming a motor in the hub of each driven wheel but then I have seen Tesla transaxles which might have differentials. My interest at present is the economics of the power source and the evolution in the electricity supply market.

Interesting video from Bjorn on EV cold charging efficiency. It is where EV would use energy to warm up battery before actually charging at full supplied power. Looks like more and more cars are doing this to protect the battery. But it would mean lower than ideal efficiency as energy is only used to heat the battery.

 

 E

Just now, J.R. said:

I didn't think it was anywhere near as high as 35%, maybe at the flywheel under wide open throttle at peak torque but far less during normal driving conditions, then there are all the further transmission losses before the energy arrives at the delivery point, the wheels, losses which I believe EVs do not suffer.

 

I admit at present I know nothing about EV power transmission, I'm assuming a motor in the hub of each driven wheel but then I have seen Tesla transaxles which might have differentials. My interest at present is the economics of the power source and the evolution in the electricity supply market.

 

Depends on what type of ICE.  Diesels are fair bit higher than petrol though petrol have caught up a lot.  Diesel with hybrid is even more efficient as an overall package of course but pricey.   ICE diesel engines in ships ie Slow speed marine diesels are close to 50% overall efficiency and considered overall, where one is generating massive of "free electricity" by using a diesecon unit ie creating super-heated steam from the exhaust to make MWs of electricity as a free bi-product the overall efficeincy is north of 50% but then one does need the space of a ten story building with about a 2500 sq metre base to achieve this. 

 

Thermo electric generators could find a place in automotive soon, replace the alternator and provide free electrical power for a hybrid system and hence jack up the overall thermal efficiency by several percentage points. 

 

22 minutes ago, J.R. said:

I'm assuming a motor in the hub of each driven wheel but then I have seen Tesla transaxles which might have differentials. My interest at present is the economics of the power source and the evolution in the electricity supply market.

Most have a motor mounted on a single speed reduction gearbox driving a transaxle with a differential.

Edited 24 November, 20232 yr by Luckypants

I based my comment on the knowledge that slow running marine diesels could reach 50% thermal efficiency, that is an engine running at a fixed speed for maximum volumetric efficiency for the given fuel, bunker diesel which is very different to road fuel.

 

Lets say for the sake of argument that a turbo-diesel can achieve 35% thermal efficiency then that will be at full load operation accelerator pedal to floor (cant use WOT for a diesel as it does not have a throttle butterfly) 3000 rpm for my engine, that thermal efficiency will only be realised in a brief transient condition when overtaking and probably above the speed limit, at normal driving and cruising engine speeds say 1200 - 2200 rpm the thermal efficiency will be way less.

 

Petrol engines are indeed improving but their maximum efficiency lets say 20% is again at wide open throttle peak torque RPM, during normal cruising with a barely open throttle the volumetric efficiency is strangled.

 

My gut feeling was that petrol fuelled road vehicles were around 9-10 percent thermal efficiency and diesel in the low to mid teens.

How come ICE cars seems to get best MPG at low RPM? It seems to be directly opposite to what you are saying where best thermal efficiency need to be at max RPM.

 

Thermo electric generator are a great read, very interesting little tech. They should be put everywhere!

30 minutes ago, wyx087 said:

It seems to be directly opposite to what you are saying where best thermal efficiency need to be at max RPM.

 

I absolutely did not say that.

9 minutes ago, J.R. said:

 

I absolutely did not say that.

 

Best efficient in energy per mile seems to be about just where the turbo achieves the normal full pressure, usually somewhere around 0.7 bar from memory.

Usually translates to around 1750 rpm in most 4 cylinder turbo diesels or petrols, sometimes a bit lower in 6 cylinder turbos, could be as low as 1250 rom incredible.

Oddly this usually relates to around 55 mph, the double nickel, which is where aero drag starts to become a significant power sapping speed.

 

Amazing that 55/56 mph is still the speed for ICE cars to do their best mpgs.  True during the early 70s crisis and still true.  

I can get 70 mpg out of the Arkana, use to get even more out of the Audi A4 with the 1.9 PD engine, I have heard of Octavias getting over 80 mpg with 7 speed DSG and 1.6 CR engine. 

  

EV can get efficiency at as low as 20 mph, ie city speeds. The Zoe can exceeds it range at 55 mph by three quarters when running at 20 mph, ie city speeds.

 

Engine match to car and driving style 3 key factors.  Sales reps would get better mpg out of 2 litre than 1.6 litre as they would cane the 1.6s.  Lots of variables.

 

On the telly last Sunday, maybe again this Sunday.  The channel is EarthxTV.  EarthxTV news.  http://earthxmedia.com

 

It was a film on container ships and it said the 17 biggest container ships in the world emit more emissions than all the road vehicles in the world in a year.

Bunker Oil  / Heavy Fuel Oil (HFO).   & Black Carbon emissions.

 

It included about the lighter fuels that can be used near land and when docking etc and the cost which i think was 4 times more expensive to use.

I had no idea that changing over to run from the heavy oil to lighter was not straightforward at sea as it was being done.

Edited 24 November, 20232 yr by Rooted

37 minutes ago, lol-lol said:

Amazing that 55/56 mph is still the speed for ICE cars to do their best mpgs.  True during the early 70s crisis and still true.  

 

Not true, they might be getting the best efficiency from the fuel but are using much more of it than at lower speeds, I do agree that each speed increment above that comes at a big price. Its the sweet spot for most of us, the compromise between longer journey times and minimising fuel cost, its also less stressfull than faster and indeed slower driving.

 

Once when I was very bored during I played with my MK1 Octavia which would happily travel at tickover in 5th gear without any applied throttle, the ECU increasing the fuelling to avoid stalling when necessary, it equated to just under 30mph in town and I would often do just that where there were speed controlled traffic lights.

 

I did a to and fro run to the next village about 5km overall, the average mpg went over the maximum 99mpg that the display would show, the instantaneous one swung wildly from zero indicated to 60mpg when it had to pour back on the coals, I did a similar run up and down the hill to the aéroport which consumed a little more but still exceeded the 99 mpg display maximum.

 

I did the same thing with the MK2 during covid with the same results, that gave the actual average, I cant recall the figure but it was well over 100mpg.

 

Of course nobody is going to drive like that for the sake of the DMF if nothing else and the road & traffic conditions would dictate frequent stops but it proved beyond doubt that when I am down to the last litre of fuel, a regular occurence with my obsession in using the entire range between fill-ups, if I dont know where the next fuel station will be the slower I drive the further I can get and that means well below 55 mph.

55 minutes ago, lol-lol said:

The Zoe can exceeds it range at 55 mph by three quarters when running at 20 mph, ie city speeds.

 

From my very rough and ready tests a diesel engine would do the same but neither would be able to cover any significant distance at 20mph without stopping and restarting frequently at which point the EV has a massive advantage.

 

I have ignored petrol engines as they are capable of being abused in the same manner driving at tickover in the highest gear including up hills.

I regularly drive a near 20 mile trip each way and have done for 35 years and have a choice of 2 different roads to do it and can do it at any speed with only a couple of junctions and often there is no traffic.

Always in Automatics though.

Inland to the coast and then return coast to inland. 

Tried is in all sorts of speeds & done it in all weathers / seasons and some vehicles are more efficient going quicker.

Keeping to 20-30 mph is seldom the most efficient speed to be doing it in a turbo petrol, diesel or EV.

A bit faster, coasting and then getting up to speed works just fine and the average speed might be between 40-45 mph.

That is now a bit less these days as 2 villages now have 20 mph speed limits where they used to be 30 mph. 

2 hours ago, J.R. said:

Lets say for the sake of argument that a turbo-diesel can achieve 35% thermal efficiency then that will be at full load operation accelerator pedal to floor (cant use WOT for a diesel as it does not have a throttle butterfly) 3000 rpm for my engine,

I'm extremely confused, I thought this bit means max or very high RPM.

 

But it is my experience that keeping RPM at lower than 2000 seems to give best efficiency for 2.0 TDI Octy.

1 hour ago, Rooted said:

On the telly last Sunday, maybe again this Sunday.  The channel is EarthxTV.  EarthxTV news.  http://earthxmedia.com

It was a film on container ships and it said the 17 biggest container ships in the world emit more emissions than all the road vehicles in the world in a year.

Bunker Oil  / Heavy Fuel Oil (HFO).   & Black Carbon emissions.

It included about the lighter fuels that can be used near land and when docking etc and the cost which i think was 4 times more expensive to use.

I had no idea that changing over to run from the heavy oil to lighter was not straightforward at sea as it was being done.

 

Those 17 ships are probably capable of carrying more than 20,000 TEUs, twenty foot Equivalent Units so probably carrying more than 200,000 tonnes of cargo so 17 of them will be carrying well over two million tonnes of cargo at any one time, they spend about 20% of their time in port loading and unloading but the other 80% of the time they are steaming at around 25 mph ie 600 miles a day, ever day including weekends.  Unlike most road transport that is probably working a third or less of the time, or 95% of the time sat still in the case of most road vehicles sat on our drives as a status symbol of how well we have done.

 

I will be working for CMA CGM in a few weeks time and they launch their LNG power 23,000 TEU vessels a couple of years ago and there will be eight more of these.

Kilo per mile of CO2 sea transport is the most efficient followed by barge, then train and air and road a long way behind.

Good to see more and more EV trucks and van as well as cars and eventually, already travelled on one in Norway, electric ships.  

 

 

2 hours ago, wyx087 said:

I'm extremely confused, I thought this bit means max or very high RPM.

 

But it is my experience that keeping RPM at lower than 2000 seems to give best efficiency for 2.0 TDI Octy.

 

You are confusing efficiency (getting the most power output from a given calorific fuel input) with lower fuel consumption, generally the slower you drive the less fuel will be used, the main reason being that drag is proportional to the square of velocity, you will consume less fuel driving at 1500 rpm in top gear, say 40mph than you will at say 55mph and 2000rpm but the engine will be burning fuel more efficiently at the higher RPM, producing more power per unit of fuel but also using far more of that power to overcome drag, reciprocating and rotational losses.

 

The text of mine you quoted was not clear in isolation, it should be read together with the other words speaking of the maximum efficiency being at max torque RPM on max power, typically on an engine brake dyno or accelerating during an overtake (hence my speaking of transient), I did say at 3K RPM for my vehicle in the text you quoted, that is a long way from maximum RPM, I rarely exceed that 3k rpm and only when overtaking etc, my cruising is between 1200 and 2200 rpm.

 

https://www.facebook.com/photo/?fbid=2679051228845565&set=pcb.2679052015512153

 

https://www.facebook.com/CelticTuningHome/posts/skoda-yeti-20-tdi-108bhp-up-to-186bhpa-skoda-yeti-5l-on-the-dyno-with-the-20-tdi/2679052015512153/

 

Edited 24 November, 20232 yr by J.R.

 

 

 

 

He seems convinced and has been banging that drum for the past couple of months, but the only price changes I see are upwards (Tesla excepted). It will be interesting to see if anything changes where there is direct competition like shown in the video.

It is growing pains with rapid roll out of the rapid charging network. 

Charge point operators need capital to grow, the return is not clear. Investors need to see the return before investing more, so prices get pushed up. 

 

Tesla is in an unique position where they can easily push through any lack of returns for charging in their car sales. At same time, their hardware and backend is cheaper due to good engineering and bigger production scale. 

 

The only way I can see for price reduction by non-Tesla charge point operators is government support, in the growth period. I think this is the area government should now focus on. The call by manufacturers for subsidies should be ignored, the product itself is already more than good enough and price competitive. It's the usage experience that needs improving. 

He keeps on about the likes of MFG and smelly forecourts, slippy foreourts.   Odd as the Charger Bays have no need to be slippy and no need to go across in front of petrol or diesel pumps if you want to go into the shop, or the nearby KFC, McDonalds, Greggs etc.   'Smells & Fumes' 'Muddy & diesel on your boots' WTF?

I have used a few sites now and nice and easy but expensive.

 

The Ionity membership joining and un-joining will suit me occasionally.    Charging costs are just far too high now with most operators / providers. 

 

Edited 20 March, 20242 yr by Rooted

1 hour ago, Luckypants said:

It will be interesting to see if anything changes where there is direct competition like shown in the video.

It's just occurred to me that this has been happening for quite a while at Banbury. There is an Osprey hub (12 Kempower 150kW) right next to the Tesla (12 V3 250kW) chargers open to all - literally 10 feet apart. This has been the case for at least a year, but perhaps ever since the Osprey hub opened? I used the Tesla chargers there twice in September and both times the Ospreys were not in use and Tesla chargers has non-Teslas charging. I just checked and Osprey are still charging 79p while Tesla are 44p off peak, 55p peak. Are the other CPOs willing to tough it out to maintain their high prices? 

Edited 20 March, 20242 yr by Luckypants

Shell are putting their charging prices UP when electricity prices are going DOWN. Go figure....

https://www.shell.co.uk/electric-vehicle-charging/public-charging-with-shell-recharge/shell-recharge-pricing.html

On 05/04/2024 at 14:35, Luckypants said:

Shell are putting their charging prices UP when electricity prices are going DOWN. Go figure....

https://www.shell.co.uk/electric-vehicle-charging/public-charging-with-shell-recharge/shell-recharge-pricing.html

 

prices of the power may be going down but the grid connection charges are up 500% in the last year. Now several thousand pounds per connector just to have power to a unit

Yesterday in Girvan where there is one Rapid Charger a New Beige Jaguar EV was plugged into the charger the whole day from early morning until night and locked in so stopping anyone else using the DC charging.

New charge is 37 pence a kWh, 60 minutes max charge time and a £30 overstay. 

They were maybe fine getting a full battery for £30,00 and treating the charger as theirs for a day.

Maybe not even 30 x 37 pence plus £30 as i have seen chargers where there is the penalty charged but not the electric charged for.

There are places where it might be a kWh tariff for 40 -say 60 minutes then £1 a minute and people just stay til full, as it is just money. 

 

......................

Lots of money...

Edited 7 April, 20242 yr by Rooted