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Mandrake
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Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Mandrake »

Tired of your Lithium Ion batteries catching fire or exploding ? Would you like to double the energy density over current Lithium Ion technology ?

Maybe you want a Solid State Lithium battery that uses a solid plastic as the electrolyte instead of a highly flammable paste, that can keep working even when stabbed with a screw driver or cut with scissors ? If so I have just the thing for you: :-D



I'm not sure when this video was recorded or how far along this guy is to making this commercially available, but a battery with 2x the energy density of current state of the art Lithium Ion that is extremely safe could be just what the BEV needs to really get it off the ground.

Of course this is not as good as the 3x energy density promised by the Sodium Ion Solid State battery I linked to earlier, and still requires lithium metal to be mined instead of sodium from sea water, however depending on which technology arrives to market first it could still be a useful stepping stone and much safer than current batteries to boot.

A battery that is not explosive and highly flammable doesn't need nearly as much heavy and explosion/fire resistant casing around it, which would reduce weight.

When you look at current battery tech for mid priced EV's like the Leaf and Zoe being in the 30-40kWh hour range, a 2x increase in energy density is all that is needed to get us past the magic 60kWh / 200 mile range point where EV's should really take off. A 3x increase in density and an elimination on the reliance of Lithium from the sodium solid state battery would be the final nail in the coffin of ICE.

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Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by NewcastleFalcon »

These are the Solid State Batteries which are currently in use in the Bollore range, including Citroen's rebadged e-mehari discussed earlier.

Bit of detail on them in this article here...

Maybe you could cast your eye over them Simon and give us your verdict? Are they ahead of the game?

https://www.blue-solutions.com/en/blue- ... batteries/

Regards Neil

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Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Mandrake »

I'm no chemist Neil so I'm not sure I can give such a verdict. :) I'll do some reading on it though.

In other thoughts, yesterday I watched a quick review for the Nissan E-NV200:



So apparently Nissan make a version of the NV200 panel van that is more or less a Leaf in disguise - same 24KWh battery, same motor etc etc. As I watched I kept thinking to myself "what's the point?", surely a van that is trying to carry heavy loads will need a bigger battery otherwise the already short range of a 24kWh leaf (70-90 miles at most) will be abysmally low when it's carrying a full load and probably weighing twice as much as a Leaf. Even 70-90 miles is of marginal use for a van, let alone the maybe 40-50 miles you would get heavily loaded.

I then stopped in my tracks and realised the error I had just made, and thought it would make an interesting point of discussion - energy/fuel efficiency of ICE vs BEV under different driving conditions such as load, speed and so on. So here are some of the factors that affect energy efficiency of ICE vs BEV vehicles - and what is apparent is that its VERY different, and requires a different driving style and mindset to get your head around to get optimal efficiency and range.

The first factor is something that I think most people are aware of - heating. First generation EV's that use a resistance heater suffer a large loss of range when the heater is on, while an ICE car suffers no loss of range at all. I suspect this is hard to get used to at first as we are all used to the "free" heating of an ICE car.

The reality is that an ICE engine is so inefficient and throws away SO much heat during normal operation (at least 70% of the total energy) that even at idle there is sufficient waste heat to maintain a comfortable cabin temperature with freezing conditions outside. All you are doing when you turn the heater on is redirecting some of that waste heat into the cabin instead of chucking it directly out into the environment via the radiator.

On an electric car the motor efficiency is >90% typically, and there is no idling either. So it would take something close to full acceleration to generate just enough heat to warm the cabin, and not enough under normal driving conditions to be useful. So early EV's used a resistance heater. Imagine a 2kW fan heater plugged into your precious 24kWh battery reserve drawing power even when you are stopped at a traffic light and you can see how this can eat through the battery and thus reduce mileage per charge. 20% range reduction is typical on these cars depending on the size of the car and battery.

A/C consumes some power and will reduce range but much less than the heater - and you get a range reduction with A/C use in an ICE car as well, so A/C use is not a big deal unless you have a model with a really small battery with marginal range to begin with.

Newer EV's use heat pumps for both heating and cooling and are MUCH more efficient, since you are more or less getting free heat from the environment. This cuts the range penalty for using the heater down to a few percent at most. The drawback of a heat pump system though is that it is not effective in very cold conditions. They work OK down to about -10 C but once you get down to -20 C or below the effectiveness of a heat pump goes way down and would have to be supplemented or replaced by a resistance heater anyway. So not too good for places like Canada, but pretty usable in the UK.

A heat pump is also more complex than a resistance heater with all the same possible failure modes as an A/C system, since it is basically A/C running backwards. If your A/C dies on you in the UK its annoying but not the end of the world - if your heater died on you that is a major problem in the winter, that would put the car off the road.

So on the issue of heating the ICE car wins hands down - however it is a bit of a Pyrrhic victory when it is only due to the gross inefficiency of ICE engines that you can get the heat for "free"...

Next up is mass - and the main subject of this post. With ICE cars we are so used to the concept that if you carry a heavier load you will use more fuel. Makes sense right ? Not really! Go back to high school physics and you'll remember that the equations for "work" done to move objects only has a height term, since raising an object increases its gravitational potential energy - in theory no energy is required to move objects horizontally, other than to overcome friction, so if rolling friction is low this will be very low.

Whilst you put energy in to accelerate something horizontally (adding kinetic energy) you get that energy back when you decelerate it to a stop at the destination, for no net energy consumption. The key is what form that energy turns into when you decelerate.

In an ICE car deceleration is done almost entirely through frictional brake pads, in which case all kinetic energy regained by decelerating goes up in heat at the brake discs, and none of it can be usefully recovered. So if you load up your car or van with a heavy load it takes a lot more energy to accelerate that heavier load up to the same speed as the empty car, thus more fuel is consumed, however when you brake all of that energy is lost as heat regardless of whether the car is empty or full - with the full car your brakes just get hotter! Therefore if your car carries twice the load you consume twice the fuel, assuming that you drive with similar levels of acceleration.

Not so with an EV with regeneration. :) Lets start with an ideal theoretical situation - regeneration is 100% efficient, you can brake as hard as you need to using regeneration, and the battery is never fully charged.

You accelerate your empty car up to speed, travel for a while then slow down to a stop. Some energy is used to accelerate but the regeneration gives you that back when you slow down. The only net energy use is tyre rolling resistance and wind resistance. Now you load the car up with a full load so that it's twice as heavy. It now takes twice the energy to accelerate to the same speed, however when you slow to a stop you get twice as much energy back! And assuming you went the same speed during the trip wind resistance will be the same, and rolling resistance would probably be similar if you inflated the tyres correctly as well.

So whilst ICE gives you penalty free heating, BEV with regeneration gives you penalty free load carrying! :-D Load your car up with passengers and luggage and still get about the same Watt/Hour per mile and same range. Add a trailer and the mass component of the trailer won't cause you any penalty - only the extra wind resistance.

Why is nobody talking about this when they criticise range loss due to heating ? [-X Ok, there are some caveats in the real world:

1) The above assumes that there is no net change in height from the start to the end of the trip. Obviously if the drive is a net climb in height (such as delivering goods to the top of a mountain) then extra energy will be consumed with extra mass, and if you unloaded those goods and then took the return downhill trip lighter loaded you wouldn't get all that energy back. However there is no way around this and an ICE car would have the same issue with delivering a load to a higher altitude. However I think for most typical driving, especially of a cyclical nature like a work commute, the net change in altitude over time would be zero. What you lose going up hill you gain back going down hill again - even if this is during a different charge cycle. It all averages out eventually.

2) Regeneration is not 100% efficient. I don't know exact figures, but its something on the order of 80%. So not perfect, but pretty good. This means that there WILL be some penalty for carrying increased loads, but it will be much less than a no regeneration friction brake scenario. At 80% the increase in energy consumption for carrying extra load would only be 20% as much as an ICE vehicle. So the extra load carrying is "mostly" free but not entirely.

3) Regeneration is limited to a certain degree of braking, usually measured in kW. For example a Tesla Model S whilst having combined motor power exceeding 400kW on the top end models will still only do at most about 50kW of regeneration when braking. Why ? A couple of reasons I can think of. Firstly many electric cars are rear wheel drive - the original Tesla models were rear wheel drive and only added all wheel drive later, with rear wheel drive models still available. The C-Zero/Ion is also rear wheel drive. (Leaf and Zoe are front wheel drive however, as is the Chevy Bolt)

What happens if you put only the rear brakes on hard in a car - like pulling on the handbrake in most cars ? You lock the rear wheels and go into a skid... Basic chassis dynamics says that you can't brake hard using rear brakes only as the weight throws to the front and the rear wheels lose traction. This is why over 70% of braking is normally done at the front, with rear brakes really only there to help keep the car straight. So if you only have a motor at the rear to regenerate then you have to limit yourself to the braking force that you can safely apply to the rear on patchy surfaces without locking the rear wheels. Any further braking would have to be done by the front wheels and if you're RWD only then it will have to be using brake pads. Naturally this issue is solved by a front wheel drive or all wheel drive configuration, however I think even FWD/AWD EV's don't regenerate more than about 50kW for other reasons.

The second reason I can think of as to why regeneration is limited is because 50kW is a lot of power - that is equivalent to a Chademo Rapid charge. So even though regenerative braking lasts for short periods of time it is a very rapid charge for the battery. Excessive rapid charging of batteries is one of the things that shortens their life so the efficiency of strong regeneration has to be balanced against not over-stressing the batteries and shortening their life. If you only have a 24kWh battery 50kW is already a 2C charge - pretty fast. In the future FWD/AWD and better batteries chemistry that can take fast charging better will allow for greater regeneration.

The end result of all this is that to get maximum benefit from regeneration and thus recoup as much kinetic energy as possible you have to limit your braking force to a level that is within regeneration ability. If you are someone that brakes hard and late you will be using the friction brakes and not get as good a range. So part of learning to drive an EV is to think about your braking ahead of time and try to brake earlier and more gently. With an EV with decent regeneration all normal slowing down in motorway and city traffic should be possible without using the friction brake - which is only really needed to hold you stationary or for emergency stops.

4) Regeneration can only take place if the battery still has some room to charge. If you charge your battery to 100% then regeneration will be disabled until the battery has been drained enough. So charging to 100% will actually reduce your overall energy efficiency as regeneration will be disabled for the first part of your journey. On an EV with a "large" battery it's typically recommended to charge up to only 80% - 80% leaves enough room for regeneration, and is also the point at which charging starts slowing down significantly. This is why rapid chargers by default only charge batteries up to 80%.

So in summary: Don't charge the battery past about 80% unless you really need to, (a bigger battery helps here!) brake early and gently as much as possible, and you will have very little penalty for carrying a heavy load.

Once batteries of sufficient capacity become available for goods vehicles like vans it will be quite interesting, the fact that you hardly pay any extra penalty for carrying heavy loads, as long as you drive within the limits of the regeneration system...

I'll cover the effect of speed on efficiency for BEV vs ICE in another post.

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Post by NewcastleFalcon »

Another excellent article Simon for the our FCF "All things electric" daily newspaper :-D

With today's rather uninspiring PSA "takeover" of Vauxhall/Opel, and prospects of rationalisation, cost-cutting, and reducing capacity,......meanwhile in China they are more than getting ready for the change to electric vehicles....
from http://oilprice.com/Energy/Energy-Gener ... -Race.html

While the Tesla Gigafactory is vitally important from an EV vertical integration perspective, the majority of new lithium-ion battery capacity is being built in China. Some of these plants are expected to be huge such as the CATL facility at 50GWh – there is little doubt that China’s lithium-ion industry has come of age.

Contemporary Amperex Technology Ltd (CATL) has plans to build the largest lithium-ion megafactory of all – but the company is little known in North America. It’s already worth $11.5 billion, and could be a dominant force globally in the battery sector if it successfully increases its lithium-ion production capacity six-fold to 50GWh by the year 2020

Other Chinese manufacturers are on a similar trajectory. Panasonic, LG Chem, and Boston Power are building new megafactory plants in China, while companies such as Samsung and BYD are expanding existing ones. All lithium-ion plants in China currently have a capacity of 16.4GWh – but by 2020, they will combine for a total of 107.5GWh.
Regards Neil
Last edited by NewcastleFalcon on 06 Mar 2017, 22:59, edited 1 time in total.

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Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by NewcastleFalcon »

No real news on the Ampera-E as a result of the GM offload of Vauxhall/Opel to PSA. Seems like GM have created a good car, that many markets would take up, but they don't seem as if they want to sell it! or they aren't organised enough to build enough of them.

https://electrek.co/2017/03/06/gm-psa-e ... qus_thread

Nice comment on the deal in General..."like shuffling deck chairs on the Titanic"

Regards Neil

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Post by Peter.N. »

Very informative Simon, although I am familiar with much of it its good to have it all in one place, as with the ICE its largely down to the way you drive, I think my driving style would gets good results with an electric vehicle as it does with my 406 Hdi, 50-60 mpg most of the time. The real problem is its going to be a long time, if ever, before I can afford one.

The ideal scenario would be an electric car running on rails in East Anglia. :wink:

Peter

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I forgot to mention in my previous post that regeneration also largely nullifies the additional weight of the battery (over a fuel tank) in terms of range and energy efficiency.

A few years ago before EV's started to take off I remember thinking that the weight of the battery to get sufficient range would simply make the car too heavy, and that heavy weight would offset any benefits of an EV drivetrain.

Turns out that's not true for two reasons -

1) An electric motor is so much more efficient (about 3x) than an ICE engine that even if you did carry the full burden of additional weight for the battery the net energy consumption would still be less due to the increased efficiency - still a net win. I mentioned this point in an earlier post.

2) However a point I have not mentioned or even thought about until a few days ago to be honest is that regeneration largely nullifies the effect of the additional weight on range and efficiency. Battery pack weight is a fixed additional weight in the car (unlike luggage, which can vary) so whilst any additional weight from a heavy battery will increase energy consumption during acceleration, you will get more energy back to charge the battery during regeneration deceleration.

If regeneration is 80% efficient and the battery weighs 300Kg, only 20% of that weight - 60Kg - contributes towards your net energy consumption to drive the car horizontally. This is about the weight of a full fuel tank, so no burden at all compared to an ICE car. Of course for this to hold true you have to drive "efficiently" in a way that regeneration can work to its fullest potential.

Driving efficiently in an EV means not only avoiding hard acceleration as it does on an ICE car (although hard acceleration doesn't hurt economy nearly as much as an ICE car, which I'll get to in another post) it also means braking in a more predictive gentle way so that you don't need to slow down faster than regeneration can manage. If you slam on the brakes at the last second you won't get the benefit of regeneration and you will pay the full penalty for increased energy consumption for heavier loads.

Regeneration also explains the perplexing fact that the total energy consumption of EV's, typically measured in Watt-Hours / Mile, doesn't vary greatly from one EV to another despite massive differences in performance/acceleration and weight. With ICE cars you can see variations of as much as 3 to 1 in fuel consumption - from 20MPG for a Xantia V6 to 60MPG for a petrol C1 for example.

Typical figures for a big heavy (2200Kg!) high performance (0-60 between 2.5 and 6.0 seconds depending on model) Tesla Model S during "normal" driving and making proper use of regeneration is about 300-330 Watt-Hours / Mile.

You'd expect the featherweight C-Zero to get at least twice as good figures as this, since it weighs only 1150Kg and is only 66hp versus up to 600hp, right ? Wrong! :twisted: Typical figures for the C-Zero are around 200-240 Watt-Hours/mile, roughly. Less energy consumption than a Tesla, but not by a factor of two! Why ? Both cars will have motors that are over 90% efficient.

Could there be a difference in regeneration efficiency ? Perhaps, although I don't believe either car quotes regeneration efficiency so it would be hard to compare. No, I believe the main factor is that regeneration itself nullifies the majority of the weight increase when you go from a C-Zero to a Tesla Model S - it takes much more energy to accelerate the heavier Tesla but you get so much more energy back during deceleration as well. So again, provided that you drive using regeneration, most of the weight increase is nullified in terms of per mile energy consumption.

So what is the main determining factor for energy efficiency per mile on an EV ? I'm glad you asked...

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Post by white exec »

You're correct about EV weight having a negative effect for acceleration, but a hugely positive one for deceleration (=regeneration) if kept within the regen abilities of the vehicle. Gently does it, in both directions!

If rolling resistance and engine/drivetrain friction is minimised - far better for EV than ICE - then air resistance remains as the largest consumer of power. Again, this can be minimised by lower and moderate speeds . . . which are the order of the day in an urban (polluted) situation. Win win, again.

I presume a whole new generation of EV tyres are being brewed - low rolling resistance, and quiet tread. Michelin well placed for all this! Higher inflation pressures might be ok, were it not for ubiquitous British potholes*.

* Unknown in Spain, by the way. My own opinion is that a protectionist cartel exists in the UK tarmac industry, which means that repairs remain ineffective. I have not seen such disastrous carriageway repairs in other European towns and cities, even in challenging climatic conditions. It's time the UK Public Accounts Committee started asking questions, and for local highway authorities to start talking to their European colleagues.

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Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Mandrake »

white exec wrote:You're correct about EV weight having a negative effect for acceleration, but a hugely positive one for deceleration (=regeneration) if kept within the regen abilities of the vehicle. Gently does it, in both directions!

If rolling resistance and engine/drivetrain friction is minimised - far better for EV than ICE - then air resistance remains as the largest consumer of power. Again, this can be minimised by lower and moderate speeds . . . which are the order of the day in an urban (polluted) situation. Win win, again.

I presume a whole new generation of EV tyres are being brewed - low rolling resistance, and quiet tread. Michelin well placed for all this! Higher inflation pressures might be ok, were it not for ubiquitous British potholes*.
You've got it in one - the number one thing that affects energy efficiency per mile for an EV (ignoring the range loss from turning on a resistance heater) at speed is air drag, followed by tyre rolling resistance. At low speeds drag drops right down and tyre rolling resistance becomes the major factor.

The difference is quite startling. For example on a C-Zero (most definitely designed as a city car despite a top speed of 80mph) the effects of speed on range is huge. Range per charge is approximately as follows, for a constant cruising speed:

70mph - 48 miles (!)
60mph - 62 miles
50mph - 75 miles
30mph - 90 miles.

Most of that is air drag, and since drag increases with the square of velocity it goes up very, very rapidly once it surpasses rolling resistance. This is the case for all cars of course but on an ICE car the better efficiency you should get at slower speed due to reduced drag is largely offset by a loss of efficiency elsewhere (using lower gears etc) so tends to disguise it.

With an EV the losses from drag at high speed are fully out in the open, and the universal rule with an EV is the slower you drive the further you can go! Even just dropping down from 70mph to 60mph and staying in the slow lane with the trucks would net you an additional 14 miles of range in the above example, not counting the aerodynamic bonus from drafting behind the truck. At 30mph you can drive twice as far as you could at 70mph purely due to aerodynamics.

So aerodynamics is a key factor in getting good motorway range with something like a Tesla having a lot better aerodynamics than the brick like C-Zero. :lol: At city speeds tyre rolling resistance is the major factor hence the C-Zero using rather narrow tyres in an effort to cut rolling resistance to a minimum.

Speed of peak energy efficiency for EV's is very different to ICE cars.

Peak MPG of an ICE car will tend to occur around the slowest speed you can travel in top gear without labouring the engine. And in the case of an automatic, when the torque converter is also locked up. So for example my Xantia V6 will change into top gear at around 35mph however it won't lock the torque converter until about 40mph - so a constant approximate 40mph at about 1500rpm will be about the most fuel efficient that car can be.

If you go any faster than this then drag starts to pick up with the square of the speed, also frictional losses in the engine from things like camshafts and accessories go up with rpm as well, and since you're already in top gear you can't lower those engine losses any further. Above 50mph the efficiency curve would be similar to an EV with a similar drag factor, with MPG dropping rapidly as the speed goes up especially past 70mph.

At lower speeds either the torque converter will unlock (a big source of inefficiency in an automatic, probably the major one) and or you'll need to change down a gear. As soon as you change down a gear or more from top gear a whole load of RPM related inefficiencies come into play. The power to turn a double or quad cam engine's camshafts against valve springs is a major source of parasitic power loss. And that power loss is only proportional to RPM, not to engine load. It can be quite high - even at full output power it can be 10-15% of the total output of the engine just to turn the camshafts and other accessories like steering pump etc.

However at the same RPM with a light load it will consume just as much power but now the overall engine efficiency goes way down since the proportion of useful power output to power to drive parasitic power losses is so much lower. Now imagine you're in 1st gear doing 10mph in a motorway jam. You might be doing 2000 rpm, which would have been enough to do 50mph in top gear but you're only doing 10mph. You still have most of the engine parasitic losses of the higher speed though, so efficiency goes way down.

In a petrol engine you also have pumping losses any time the throttle is nearly closed. Running in a low gear at higher rpm with a lightly opened throttle at slow speeds - like motorway stop start crawl, is the worst thing you could do in an ICE, besides just sit and idle. MPG is horrendous because you still have all the overheads in the engine but the low gearing means you're hardly going anywhere...

You don't have any of these low speed efficiency problems in an EV. EV's are simple and straight forward - the slower you go the more efficient it is for energy used per mile. (Again if you assume the heater is turned off, which would be a power draw regardless of speed of travel) There is no idling so if you're not moving you're not using any real power. And if you are crawling along at 10mph then losses in the motor are very low because the gear ratio has not changed - the motor is just turning really slowly.

If you're speeding up and slowing down a bit - which you typically are in stop start traffic, most of the energy from speeding up can be recovered during slowing down again, although its still more efficient to drive at a constant speed which is the average of the car in front of you. (Not always possible though)

In short, at low speeds and especially in stop start traffic EV's shine, and their energy efficiency goes way up, compared to getting worse at slower speeds in an ICE.

If I could choose between 30mph stop start traffic and 50mph free flowing motorway, my Xantia would get better MPG on the motorway (at 50 anyway, probably not at 60 or 70) than the 30mph, however an EV would get much better mileage in the 30mph stop start traffic!

Another big difference between EV's and ICE is the loss of mileage during hard acceleration in an ICE. In a petrol or diesel the actual efficiency of the engine itself varies widely with RPM and load, and has its best efficiency towards the lower RPM end with a moderate load.

If the load is too light (like idling) then the parasitic power losses in the engine like camshafts will swamp the useful power output and overall efficiency will plummet. (Down to 0% at idle...) Conversely if you floor the throttle and rev it to get peak power output efficiency will also plummet - partly due to the high frictional losses at high rpm and high loads (such as piston side thrust) and partly due to the fact that the mixture in the case of a petrol will have to be a lot richer than stoichiometric to get maximum power and prevent damage to the engine. The end result is that efficiency at full throttle is much worse than it is under cruising conditions.

So there is a bump somewhere in the middle of the load range where efficiency is best (and will give best cruising MPG) with it falling off rapidly towards minimum or maximum load.

This is not really the case with an EV. Good electric motors are over 90% efficient in nearly ALL operating conditions. It doesn't matter if the motor is putting out just enough power to creep along in stop start traffic, cruising moderately, or putting out its full rated power. In all cases efficiency is uniformly very high and pretty much constant regardless of load or speed.

That means that there isn't actually much penalty to hard acceleration in an EV, at least from the perspective of the motor efficiency. What can change is that the batteries themselves can become a bit less efficient at higher output, however this depends a lot on the specific battery chemistry, and how large the battery is in comparison to the load being drawn by the motor. For example if you're trying to put out 120kW of power to accelerate and you only have a 30kWh battery, you're discharging it at a 4C rate which is pretty high. There will be some temporary capacity loss from doing that. However the same amount of acceleration from a 60kWh battery is only a 2C rate - which is much easier on the battery. The loss of efficiency of the battery would be much less therefore the overall energy efficiency penalty from that hard acceleration is much less.

For current Lithium Ion batteries the maximum safe discharge rate for short term bursts of high acceleration without unduly affecting the lifespan of the battery is about 5C or 5x the kWh rating of the battery. So on a 100kWh Tesla that's a peak power output of around 500kW.

As batteries get bigger in capacity and better chemistry is found the efficiency loss in the battery from hard acceleration will be even less than it is now.

As always, it's the batteries that are still the limiting factor. [-X
* Unknown in Spain, by the way. My own opinion is that a protectionist cartel exists in the UK tarmac industry, which means that repairs remain ineffective. I have not seen such disastrous carriageway repairs in other European towns and cities, even in challenging climatic conditions. It's time a Parliamentary Committee started asking questions.
I couldn't believe how bad the potholes and state of the road are over here in the UK after moving from New Zealand.

I used to grumble about potholes in NZ but they were fairly isolated and not in large numbers. Here they aren't just in large numbers, whole sections of road are just broken surfaces that are a mishmash of holes, temporary patches and so on, that looks like someone has been out quilting on the road! :roll:

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Post by harryp »

Just a "throw in". In the '70's I remember reading that to propel an "average family" car at 50 mph took around 15 BHP. .. and drag coefficient as you know, is a pretty useless way of comparing the power required to push a car along as the power required an anything over about 50 Mph starts to rely heavily on the streamlining of the body work. Would still l love to see the 30/40/50/60/70/80 Mph values on "modern" vehicles :wink: :wink:

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Post by white exec »

Peter's celebrated 'light right foot' sets something of a benchbark, I know.
Our 2.5TD XM normally turns in 34-35mpg here - mixed everything - which is tolerable enough. So was decently surprised when we drove from the south to the north of Spain (and on to the UK), and averaged a real 41mpg at an average speed of 62mph. Most of that on clear motorways, cruising at 75mph (120km/h). Shows what a bit of cruising can do, with a very slippery shape.
My guess is that Peter would have hit 50mpg++ without a problem.

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Post by Mandrake »

Another article referring to John Goodenough's solid state battery which goes into a bit more detail:

http://spectrum.ieee.org/energywise/ene ... end-of-oil

Looks like the basic approach can use either Lithium or Sodium as the active metal, although it's unclear whether both would give the 3x energy density of a conventional Lithium Ion or only Sodium. I suspect the increase in energy density comes from the "electrolyte", which in this case is a type of glass! (I still can't wrap my head around a battery with a solid electrolyte like glass or plastic, but I'm no chemist. :) )

The interesting thing is they talk about the dielectric factor of glass being much higher than conventional electrolyte, which is true, but the way they describe it makes it sound like some portion of the energy storage is electrostatic - eg what you have in a capacitor or super capacitor. This is very different than the migration of ions, which is what happens in a battery.

So does that mean that this solid state battery technology is both a battery (with ion's migrating through the solid "electrolyte") and a capacitor (with electrostatic charge stored across a dielectric formed by the same glass layer) effectively connected in parallel ?? If so, that is very cool! :-D

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NewcastleFalcon
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Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by NewcastleFalcon »

Didn't switch on to that "fascinating" tradition today..."The Budget"....fully expected it would be boring and from the little bit I picked up accidentallly from the internet, not much radical addressing of transport/pollution/energy matters and the headline being that in 1hour or so of speaking the word "Brexit" was never mentioned....not once!

Yawn yawn. Kicked the Diesel scrappage scheme down the road a bit, not sure even if they are going to bother to tax them out of existance...probably don't want to upset people ie motor manufacturers and traders with diesels to sell.

If I could be bothered I could read the awfully named "Oral Statement to Parliament" in full

https://www.gov.uk/government/speeches/ ... nds-speech
Today to enhance the UK’s position as a world leader in science and innovation, I am allocating £300 million of the fund to support the brightest and the best research talent, including support for 1000 new PhD places and fellowships, focused on STEM subjects.

£270 million to keep the UK at the forefront of disruptive technologies like biotech, robotic systems and driverless vehicles.
"Disruptive Technologies" :?: Must mean something....this is it apparently
A disruptive innovation is an innovation that creates a new market and value network and eventually disrupts an existing market and value network, displacing established market leading firms, products and alliances. The term was defined and phenomenon analyzed by Clayton M. Christensen beginning in 1995.
Can't get more disruptive than Electric Vehicles :-D

On a slow news day, yes there is the Geneva Motor Show going on, and Renault have showcased a tarted up Zoe with a "sporty look", and loads of other manufacturers parade their ultra expensive offerings which can go from 0-60 in under 3 seconds. Personally speaking I couldn't care less how fast a car can get to 60mph, and should I happen to see someone engaged in that activity on the roads of Northumberland the phrase "What a w****r" wouldn't be far from my lips.

Here's the Zoe from an article on Elektrek "Renault unveils a sexier version of its all-electric ZOE in Geneva: ZOE e-Sport Concept"
https://electrek.co/2017/03/07/renault- ... oe-geneva/
Regards Neil

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Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Gibbo2286 »

I watched the budget speech all through, I did have a chuckle when he mentioned 'driverless' cars and as an aside said "Well members opposite will know something about that."

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white exec
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Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by white exec »

Just a shame his admirable competency and diplomacy at Defence has now given way to arrogance, sneering and excessive 'joke' cracking. In the circumstances the UK is now in, all that is quite inappropriate. Absolutely no laughing matter.

Sorry about the politics, Jim. Will try not to do it again.