Electric Vehicles

[Adam Ef]

Owning a Passatt as a family car I looked at the VW option... £30k-£40k ... erm. no.



If I owned one I'd want it fully electric otherwise you're still lumbering yourself with the work needed and servicing etc for a combustion engine as well as the cost of the electrics.

[Luckypants]

Originally Posted by Dave20046

Fast charge does seem to be a nono still though. It's going to be the new 'one lady owner' - 'one laid back git who never needed to get anywhere quick'.

https://www.youtube.com/watch?v=IHz-Kx5h_Tw

It seems to be dependant on a number of things with rapid charging. First off is how well the car itself looks after the battery, active heat management makes a big difference. Tesla have always charged well as they have always had liquid cooling of the battery pack. Nissan Leafs on the other hand have no active battery cooling and rely on the air wafting around to cool the battery - on long trips Leafs "rapidgate" as the battery gets hot charging and is not cooled enough driving, this leads to the charging system throttling the charge to a crawl to prevent the battery overheating. The other issue with rapid charging is taking it to 100%, as this is where the most damage can be done and all EVs throttle back charging as they fill up to prevent battery damage. The recommendation is to charge to 80% max unless setting off on a long journey and not to charge to 100% on a long journey via a rapid charger. Take a look at this, high mileage Teslas which were almost exclusively Supercharged https://electrek.co/2018/07/17/tesla...miles-3-years/

I know I am going on about Tesla, but thats because they are market leaders and also have been around a long time in EV terms, so there is a lot of data about how the cars perform. I will also refer to Nissan Leafs a lot for the same reasons. Renault Zoes are starting to give useful long term data now after being out 4+ years, (In fact I slightly regret not getting one when we had to replace the little car) but the current Zoe is very different to the original.

[SV650rules]

Originally Posted by Dave20046

I was surprised the batteries don't degrade too fast (if looked after), guess I shouldn;t be at the price...it's a whole different kettle of c0cks to a iphone or laptop that I'm basing experience on. Fast charge does seem to be a nono still though. It's going to be the new 'one lady owner' - 'one laid back git who never needed to get anywhere quick'.

The BEV batteries are same technology as an i-phone or samsung battery - just bigger. When you get a new BEV the computer limits the charging and discharging of battery to 80% and 30%, this is like having a 50 litre fuel tank on a car and not being able to fill it more than 40 litres and not being able to use the last 15 litres. This is done to protect the battery ( so the car is actually lugging around a battery that is only half used, and unlike a fuel tank a battery does not get lighter as the fuel gets used ).

As the battery ages the limits are increased to say ( maybe 12 months ) to 85% and 25% in order to use more of the degrading battery to preserve range. When it come to range that is a whole difference between what makers claim and what you can achieve. Take a BEV on the motorway and you get 60% of claimed range, unless you want to go everywhere at 50mph and live in a flat area like Norfolk. Fast charging is also a no-no - I read of a bloke who actually sued Nissan - he had waited for the new larger capacity Leaf to go on sale - a claimed 235 miles and fast charge from empty ( by which they mean 30% ) to 80% ( by which they mean full ) in about 90 minutes. he found that he never got more than 150miles range and the control system on the car would not allow more than 1 fast charge per day - so on his trip from Yorkshire to Cornwall he was stuck on motorway services for hours while his car 'slow charged'.... A trip that would take 6 hours in an ICE car took him all day, most of it spent on motorway services. Anyone with a boat, caravan or anything else that needs towing should avoid BEV, they 'don't do towing' - the battery gets flattened quicker than a hedgehog on a motorway.

As for one lady owner, if the battery is left hooked up for too long not being used it damages it, if the battery is left in a discharged state for too long it damages it... there are a lot of things makers try to hide when advertising electric cars, and so does the government in their headlong rush to de-carbonise UK ( even though we produce less than 1.5% of worldwide emissions ) - the main result of our rush to de-carbonise is to drive jobs offshore, to places that are not as silly as we are ( Germany was building coal fired power stations until very recently and China never stopped building them ). You cannot run a country when you rely on fans on sticks for your electrical power.

[Luckypants]

Originally Posted by SV650rules

The BEV batteries are same technology as an i-phone or samsung battery - just bigger. When you get a new BEV the computer limits the charging and discharging of battery to 80% and 30%, this is like having a 50 litre fuel tank on a car and not being able to fill it more than 40 litres and not being able to use the last 15 litres. This is done to protect the battery ( so the car is actually lugging around a battery that is only half used, and unlike a fuel tank a battery does not get lighter as the fuel gets used ).

Wrong. You are confusing the recommended range for state of charge with physical limits. The recommended maximum charge by most manufacturers is 80% for everyday driving and to plug in to charge at about 20%. The upper limit is to prevent damage by sustained high state of charge, apparently keeping a lithium battery at 100% will promote dendrite growth and lead to loss of capacity. The lower limit is just like a low fuel warning, you get prompted to charge and eventually you would go into limp mode at below 10%. The car shuts down at 0%. The percentages here are of usable battery.

There are physical limits to the battery imposed by the manufacturer and these are 1 or 2% of the battery's physical capacity. These are to protect from damage from overcharging or being discharged to absolutely empty - that will kill a lithium ion battery. These upper and lower buffers are well known from phone and laptop applications and are often not counted as part of battery capacity. The percentage state of charge in an EV does not include these buffers and 100% charge for instance is 100% of usable battery. An example I can quote is the new Skoda Enyaq will have an 80Kw battery but will have 77Kw usable battery.

Originally Posted by SV650rules

As the battery ages the limits are increased to say ( maybe 12 months ) to 85% and 25% in order to use more of the degrading battery to preserve range.

Wrong. Battery degradation is known and battery warranties are based on having a certain percentage of usable battery after x years. Most offer 75%-80% still usable after 8 years.

Originally Posted by SV650rules

When it come to range that is a whole difference between what makers claim and what you can achieve. Take a BEV on the motorway and you get 60% of claimed range, unless you want to go everywhere at 50mph and live in a flat area like Norfolk.

True. Like fossil cars, fuel consumption goes up at high speeds like motorway driving. The WLTP measurement cycle is well known to be inaccurate for both ICE and electric vehicles.

Originally Posted by SV650rules

Fast charging is also a no-no - I read of a bloke who actually sued Nissan - he had waited for the new larger capacity Leaf to go on sale - a claimed 235 miles and fast charge from empty ( by which they mean 30% ) to 80% ( by which they mean full ) in about 90 minutes. he found that he never got more than 150miles range and the control system on the car would not allow more than 1 fast charge per day so on his trip from Yorkshire to Cornwall he was stuck on motorway services for hours while his car 'slow charged'.... A trip that would take 6 hours in an ICE car took him all day, most of it spent on motorway services.

Like all cars, consumption depends on use. See above about WLTP range predictions. The rapidgate for multiple rapid charges for the Nissan Leaf is a well known issue and makes it useless for long distance. See one of my previous posts about the lack of active battery cooling on Leafs. The newly announced Nissan Ariya will fix this. Tesla/VW/Audi/BMW I3/Porsche/Jaguar etc all have active battery cooling and can be rapid charged as often as needed, although it does slow down on hot days when battery gets warmer - but that won't be a UK issue. How did this bloke get on with suing them?

Originally Posted by SV650rules

Anyone with a boat, caravan or anything else that needs towing should avoid BEV, they 'don't do towing' - the battery gets flattened quicker than a hedgehog on a motorway.

True, but as most EVs are not rated to tow, fitting a towbar is illegal due to construction and use regulations. However, towing anything in a car will dramatically increase consumption, so hardly surprising range takes a hit. A 500 mile range diesel car won't do that pulling your caravan ether.

[embee]

The whole business of "green" is veiled in smoke (sic) and mirrors. Electric vehicles are no exception. You have to ask the question "what is the purpose of the action?"
If the purpose of electric vehicles is to improve air quality in cities, reducing NOx and particulates, then absolutely bring it on.
If it's the thought that it reduces CO2, then take a step back and look at the reality.
Consider a true electric vehicle (battery only, BEV). A small BEV like a Nissan Leaf will do around 4mls/kWh of battery charge, a larger one (Tesla etc) are probably nearer 3mls/kWh. If the electricity is generated by wind or water, great ................ except it isn't. Assessments vary, but we still use gas to generate around a third of our electricity (23Twh out of about 75TWh total per quarter)
https://www.ofgem.gov.uk/data-portal...fuel-source-gb
Gas generation produces around 500gCO2eq/kWh, so even ignoring transmisson/charging losses, that's around 125-170g/mile (so probably more like 150-225g/mile in reality) for your typical BEV.
A small petrol car produces around 200g/mile (125g/km), a medium car around 300g/mile.
http://www.aef.org.uk/downloads/Gram...ortmodesUK.pdf
You can see that a small petrol car actually is quite comparable to a similar BEV for CO2 emissions if the electricity is produced by burning gas, a BEV equating to maybe 75% of the petrol car. As long as we use gas for the marginal generation to react to demand above the baseline for renewable/nuclear the savings are not that great and certainly nothing like some would have us believe. If we can increase the renewable up to a much greater share then we start to be in business. It might be argued that forcing the switch from IC to BEV may not be the most cost effective use of investment, there are better ways to reduce net CO2 globally.
The argument is similar for the idea of getting rid of domestic gas boilers. As far as I can find, a typical domestic boiler works out at around 220g/kWh heat produced, that's less than half the CO2 produced by burning gas in a power station and heating your home with electricity. Bonkers suggestion to ban domestic gas boilers until the generation is predominantly by renewables and much less by gas.
BEVs certainly have other attractions, servicing implications etc.

[SV650rules]

Originally Posted by Luckypants

The percentage state of charge in an EV does not include these buffers and 100% charge for instance is 100% of usable battery. An example I can quote is the new Skoda Enyaq will have an 80Kw battery but will have 77Kw usable battery.

The limits are still imposed by battery manufacturers when battery fitted to a car or other vehicle, the battery chemistry is still the same whether a battery is in a phone or a car. The 80/20 rule is imposed by the cars charging control computer and are not visible to the owner, when it says 100% on the screen in the car it is not 100%, and the car will stop moving at 20%, not just show a warning light - Tesla remotely unlocked the minimum charge limit on their cars during the last hurricane in USA to allow drivers to go further. When Top Gear tested a Tesla the car stopped at roadside and Jeremy Clarkson called dealer to tell them to come with a tow truck - a bloke turned up with a laptop and 'unlocked' last 20% of battery so the car could limp to a charge station.

Oh and another thing, not only can you not tow with an electric car, you cannot tow an electric car either, there is no neutral position in transmission and you can damage motors , electronics and battery if you try to tow it like a normal vehicle. So you will need a flatbed trailer type tow truck ££££££££'s

Li-Ion batteries get stored at about 40% charge after manufacture for longest possible shelf life, there is a damned good reason for this as a charge level above or below that reduces battery life.

[Dave20046]

Originally Posted by SV650rules

The limits are still imposed by battery manufacturers when battery fitted to a car or other vehicle, the battery chemistry is still the same whether a battery is in a phone or a car. The 80/20 rule is imposed by the cars charging control computer and are not visible to the owner, when it says 100% on the screen in the car it is not 100%, and the car will stop moving at 20%, not just show a warning light - Tesla remotely unlocked the minimum charge limit on their cars during the last hurricane in USA to allow drivers to go further. When Top Gear tested a Tesla the car stopped at roadside and Jeremy Clarkson called dealer to tell them to come with a tow truck - a bloke turned up with a laptop and 'unlocked' last 20% of battery so the car could limp to a charge station.

Oh and another thing, not only can you not tow with an electric car, you cannot tow an electric car either, there is no neutral position in transmission and you can damage motors , electronics and battery if you try to tow it like a normal vehicle. So you will need a flatbed trailer type tow truck ££££££££'s

I'm now an expert after watching 3 youtube videos and it sounds as though they have cooling technology in the cars that don't appear in iphones etc. That rings true with my own experiences of failing iphones after getting extremely hot.
The statistics cited in the videos directly linked hot batteries to prematurely aged batteries. If the batteries genuinely do more often than not last nigh on a decade (and are still usable in that lifetime) I'm a bit less worried about them on that front.

Other than that I have nothing to add

[SV650rules]

Originally Posted by embee

The whole business of "green" is veiled in smoke (sic) and mirrors. Electric vehicles are no exception. You have to ask the question "what is the purpose of the action?"
If the purpose of electric vehicles is to improve air quality in cities, reducing NOx and particulates, then absolutely bring it on.
If it's the thought that it reduces CO2, then take a step back and look at the reality.
Consider a true electric vehicle (battery only, BEV). A small BEV like a Nissan Leaf will do around 4mls/kWh of battery charge, a larger one (Tesla etc) are probably nearer 3mls/kWh. If the electricity is generated by wind or water, great ................ except it isn't. Assessments vary, but we still use gas to generate around a third of our electricity (23Twh out of about 75TWh total per quarter)
https://www.ofgem.gov.uk/data-portal...fuel-source-gb
Gas generation produces around 500gCO2eq/kWh, so even ignoring transmisson/charging losses, that's around 125-170g/mile (so probably more like 150-225g/kWh in reality) for your typical BEV.
A small petrol car produces around 200g/mile (125g/km), a medium car around 300g/mile.
http://www.aef.org.uk/downloads/Gram...ortmodesUK.pdf
You can see that a small petrol car actually is quite comparable to a similar BEV for CO2 emissions if the electricity is produced by burning gas, a BEV equating to maybe 75% of the petrol car. As long as we use gas for the marginal generation to react to demand above the baseline for renewable/nuclear the savings are not that great and certainly nothing like some would have us believe. If we can increase the renewable up to a much greater share then we start to be in business. It might be argued that forcing the switch from IC to BEV may not be the most cost effective use of investment, there are better ways to reduce net CO2 globally.
The argument is similar for the idea of getting rid of domestic gas boilers. As far as I can find, a typical domestic boiler works out at around 220g/kWh heat produced, that's less than half the CO2 produced by burning gas in a power station and heating your home with electricity. Bonkers suggestion to ban domestic gas boilers until the generation is predominantly by renewables and much less by gas.
BEVs certainly have other attractions, servicing implications etc.

The problem is that the people who are 'driving' the green agenda ( politicians ) have no understanding of much except fiddling their expenses and talking - they rarely understand logic or science. They are however open to lobby groups bearing brown envelopes...... Modern gas boilers are about 90 to 95% efficient at extracting heat from gas, you put a power station and distribution network into the equation and you get nowhere near that figure. Remember these are the people who dreamed up 'bio-mass' = chopping down forests and shipping the resulting wood pellets 1000's of miles to burn in a power station. These are the same politicians that reduced investment in UK industry that much that we can no longer build our own nuclear power stations ( advanced gas cooled reactors which are the safest design in the world ) and rely on other to build dodgy and dangerous water cooled reactors.

[Luckypants]

I explained the difference between physical buffers and usable SoC. This 80/20 rule you are stating is complete rubbish. Please point out an article that demonstrates this rule and so contradicts everything I've read for the past 2 years.

For example "The battery of the Volkswagen ID.3 Pro S has a total capacity of 82 kWh. The usable capacity is 77 kWh." https://ev-database.uk/car/1203/Volkswagen-ID3-Pro-S By your concept of "you can only use 80% down to 20%" (60% of the battery) an ID.3 would have a useable battery of 49.2Kwh (82*0.6).

Wrong.

[SV650rules]

It is the chemistry of the battery, which is the same for a phone, laptop or car. The chemistry does not change because the battery is fitted to a car. The upshot is that the car is carrying a battery around that is larger than needed because of the limits of its charge and discharge on number of charge and discharge cycles. The limits of li-Ion batteries are well documented, and have always been there - the are better than the NiCad and NiMh that we used to have ( that had a memory effect built in ) - but all batteries have their limits, your lead acid motorbike or car batteries get sulphated up if regularly kept below 70 to 80% charge, and get damaged if fully discharged.

https://www.eyerys.com/articles/40-8...mical-problems