MSE Guide - Electric vehicles

Xbigman

I'm not going to quote a ton of people and dissect everything but I'll make a couple of observations. 

My ebike battery will last approximately 500 cycles before it drops below 80% capacity. EV batteries are less 'stressed' than ebike ones in terms of discharge rates vrs total capacity so should last longer. But using ebike battery life spans an EV that starts with a range of 220 miles and 500 cycles (charges) later has a range of 180 miles will have traveled 100,000 miles. And that battery will still work but the range will deteriorate more rapidly after that. Many cars will never need a new battery. The potential fly in the ointment for EV owners is that many batteries have a stated lifespan of 10 years. That might become an MOT issue in the future but it isn't yet.
Exactly how sensible it is to use super chargers to speed charge and stress the battery remains to be seen. Likewise allowing your EV to be drained to power the national grid will be burning up battery life. Any payment you get for that should include something towards a new battery one day.

Particulate matter is an issue. Its being ignored because its not an urgent issue. I suggest that anyone who lives near a recently built motorway (I don't) who now suddenly finds their entire house covered in dust every day may be better qualified to give an opinion than the government or so called industry experts.

Weight of vehicles is an issue. Having worked in the transport industry for decades I've seen some big changes and their effects. I can remember when the government allowed bigger and heavier lorry weights on the basis that the axle weights were the same. My employers move over to high capacity triple axle articulated trailers immediately. When I say immediately I mean it. All the equipment was in use months before the law changed and on the day it changed any lorry leaving the depot after midnight was using the higher capacity load limits.
At that time the depot yard was brick. A nice grippy brick that allowed good drainage. Bit by bit the triple axle trailers ripped the bricks up on the corners of the yard where lorries turned, that's OK because the bricks were replaced with concrete. Then a bit more and more, and more. The whole yard is now concrete and floods regularly. The higher axle weights are seen as a great success by the government and the haulage industry. But there were consequences. Consequences that few will acknowledge.

That brings us to EV weights. There was an opportunity for the government to show some leadership. Successive governments in fact. But once again they didn't. We should already know how EV's will be taxed in the future (it looks like pay by mile is favorite) and more importantly what the tax classes will be. Instead the government just let the motor manufacturers and the mythical 'market forces' do their thing in a vacuum. Result - manufacturers simply took FF cars and stuck batteries in them. The manufacturers then decided this was what people wanted and kept doing it, starting an inexorable increase in car weights and volumes. To be fair this trend was already there, EV's just accelerated it a bit. But weight is a concern. One day EV owners will wake up to the news that EV's will be taxed on a pay by mile system, and it won't be cheap. And by a mysterious coincidence the cheapest tax brackets will be just under the weight of most existing EV's. There are a few niche vehicles like the Twizzy and Ami but unfortunately niche = looks crap.

Finally. Regenerative breaking. Its a gimmick. It was tried with ebikes but the extra weight reduced ebike ranges by more than was gained. Its a slightly different situation with EV's where there is a real increase in range to be had but it depends on driver behavior to get the best increases and then its only a few % extra. You will never recover the cost of having it in the first place. 


Darren

MWT

Xbigman said:

Finally. Regenerative breaking. Its a gimmick. It was tried with ebikes but the extra weight reduced ebike ranges by more than was gained. Its a slightly different situation with EV's where there is a real increase in range to be had but it depends on driver behavior to get the best increases and then its only a few % extra. You will never recover the cost of having it in the first place.

The vast reduction in brake use and the associated wear and particulate generation is real though, nearly 4 years of regular driving and there is still no discernable wear on my brake pads...

Petriix

I will never understand why people feel the need to make stuff up. Regenerative braking is far from a 'gimmick'. It doesn't add any weight, motors become generators when you reverse the current. If you don't understand the physics then stay out of the discussion because you're just adding misleading nonsense. 

An extra 100kg isn't going to make such an enormous difference in practice. And EVs are vastly less complicated than ICEVs, having a tiny number of moving parts in comparison.

It's an objective fact that EVs produce a small fraction of the particulate emissions of the equivalent ICEVs. It's not zero, but it's not comparable in any way. EVs generate slightly more tyre wear, but you have to weigh that up against zero tailpipe particulates and practically zero brake dust. Regenerative braking means that you only use a tiny amount of friction to slow down (unless you drive like an idiot).

DaveDarpen

I have been running a Nissan Leaf for 2 1/2 years now, so I have a few comments.

1. Home Charging
I have no drive and park on the road outside my house, using a heavy duty rubber black and yellow cable protector across the pavement. I first checked with Hampshire Highways that this was allowed and it is. 

The article says it is "Not recommended to use a normal 3 pin socket." Oh yes it is! I have been doing so since I first got an EV and have never had any issue. The cable came with the car, and draws 2.4kW power. It plugs into an outside socket, which has its own dedicated outlet in the consumer unit. When visiting friends I plug into their ordinary sockets no problem. I thought about forking out over £1,000 to have a charging point at my house, but couldn't see any reason for doing so. If I have to go somewhere at short notice, there is a rapid charger up the road. Otherwise overnight home charges are sufficient for me.

2. Variable Range
This was really interesting to me. The Electric Vehicle Database (you can google it) gives the ranges of different cars in different conditions. The main variations are ambient temperature (less range if it's cold) and whether you are driving in town or on the motorway (oddly, EVs are more economic in town than on the motorway). The differences are staggering - these are for the Nissan Leaf:
On the motorway at -10C: 105 miles
On the motorway at +23C: 135 miles
In town at -10C: 145 miles
In town at +23C: 220 miles.
[These assume you have heating on in the cold, but no A/C at 23C]

[Deleted User]

One of the key factors affecting range is speed or, more precisely, drag. A vehicle driving at 60mph on a motorway has 4 times the aerodynamic drag of the same vehicle driving around town at 30mph. The drag at 20mph is 1/9 of what it is at 60mph. This is known as the ‘squares rule’.

The same aerodynamic effect is encountered when driving a non EV.

Grandad2b

How do the costs stack up with the new price cap? Are specialist EV tariffs still available?

I hear that most EVs get around 3 or 4 miles per kWh which means that paying 52p per kWh makes the fuel cost very similar. And petrol and diesel have started to come down a little from their peak a couple of months ago.

Petriix

Grandad2b said:

How do the costs stack up with the new price cap? Are specialist EV tariffs still available?

I hear that most EVs get around 3 or 4 miles per kWh which means that paying 52p per kWh makes the fuel cost very similar. And petrol and diesel have started to come down a little from their peak a couple of months ago.

Yes, Octopus Go is still around (7.5p off peak, ~ 40p peak). I wouldn't personally recommend switching to an EV if you're on the price cap and don't have access to free or cheap charging. 

michaels

We have only had an ev for 8 years (purchased new in April 15 for £12,300) so no doubt know much less than most who comment who have never even been driven in one let alone owned one.

In that time and 78k miles we have not had to replace the brake pads - nor the engine oil(!) and indeed the only part we had replaced were the suspension drop links for less than £50 fitted by an independent.  We have also had to replace the tyres twice, each set lasted about 35k miles.  Probably had a couple of cabin air filters and screen-wash and new front wiper blades too.

The battery is at 84% of its original capacity which means the range has also declined by that much compared to new, engine power output is unchanged and there remain the same zero tail pipe emissions as when we bought it.

Our current electricity tariff costs 4.5p per unit at night when we charge (we also use the car battery a a storage battery and all our day electricity thus also costs 4.5p per unit).

We rarely travel more than 80 miles in a single trip but on the odd occasion use fast chargers, despite our car being old and relatively slow charging, a 20 minute charge stop is normally plenty for us to complete our journeys.  Even then this can be done sitting inside in the warm car not standing out on a cold, fumesy forecourt.

Agree with the other posters, EVs only work for those who can charge at home as otherwise fuel costs are high and you have the disadvantage of slower fuelling than with petrol - apparently this is about 60% of car owners but almost certainly a higher proportion of new car purchasers.

Fluffykins

Martins exhortation to renew your EV tax before the end of March isn't limited to those with tax expiring in a couple of specific months. As EVs are currently £0 VED rate it makes perfect sense to re-tax irrespective of when your VED runs out. You CAN do it. You'll just need the reference number on your V5 registration doc. My tax expires in December. I re-taxed successfilly earlier this month. Go figure.

Qyburn

agentcain said:

Disagree on the 2nd point. Everything is not a matter of conversion efficiency but also about storage, weight and time efficiency. Hydrogen sits higher on the specific energy scale, offering more energy per unit of mass, which means less weight to move around. It also offers the benefit of faster refuelling, something battery technologies still can't touch. 

Those are points in favour, but i disagree with the view that efficiency doesn't matter. The hydrogen plant I visited said they "hoped to reach" 65% efficiency, but didn't say what they were actually achieving. That's efficiency based on calorific value compared to electricity used, not accounting for fuel cell or other losses when it's used.

If it used surplus electricity then that would be fine, 65% of something that would otherwise be wasted. But the plant cant run like that, the efficiency they were hoping for requires a good 8 to 10 hour run. It can't stop and start depending on generation mix. So in spite of the "use green renewable electricity" and their pictures of wind turbines the reality is that a lot of thor production is fueled by burning gas.