Navitron Renewable Energy and Sustainability Forum

Transport (electric vehicles, alternative fuels, biofuels, conventional fuels, fuel efficiency, air travel, trains) => Electric vehicles, alternative fuels, biofuels, alternative transport, conventional transport => Topic started by: Bodidly on May 11, 2019, 07:29:06 AM



Title: Thoughts on a second hand EV
Post by: Bodidly on May 11, 2019, 07:29:06 AM
So we are looking to change our car and wondering if it's time to go for an EV. Average 8000 miles a year with the majority of it being less than 10mile round trips. A few 25 mile round trips and the occasional trips to the inlaws which is 130 miles relatively hilly miles. Need space for 2 people, luggage and dog. And Liz recons 100hp as she likes a bit of nip. What are the considerations when looking at SH EVs?

Thanks
Beau


Title: Re: Thoughts on a second hand EV
Post by: oliver90owner on May 11, 2019, 07:47:49 AM
It appears to be a sellerís market at the moment.  Too few new vehicles available and too many wanting them!  That means relatively few vehicles coming up for second person ownership.

Are you wanting views on which models to look for, or general tips/warnings of what not to buy?

PLP cars will likely not have had the battery looked after, as the first owner likely decided to hand the vehicle back when the lease ended.  Short range leads to charging to 100%, discharging to a low state of charge and repeated fast charging.  These all stress the battery, so the state of health of the battery is paramount when considering any second hand electric car.


Title: Re: Thoughts on a second hand EV
Post by: Bodidly on May 11, 2019, 08:40:19 AM


Are you wanting views on which models to look for, or general tips/warnings of what not to buy?



Both. I know diddly squat about them really and also get lost with all the acronyms. I have solved most it here https://pod-point.com/guides/driver/ev-dictionary  but PLP?


Title: Re: Thoughts on a second hand EV
Post by: HalcyonRichard on May 11, 2019, 10:25:19 AM

Short term hire = good to try :-

https://www.evezy.co.uk/

https://evexperiencecentre.co.uk/

Good forum

https://www.speakev.com/recent-activity/

Richard


Title: Re: Thoughts on a second hand EV
Post by: Bodidly on May 11, 2019, 11:30:24 AM
That evezy link looks interesting. Quite tempted to try a Zoe for a bit and see how we get on with it. Shame we would have to go all the way to Bristol but not a deal breaker.

Thanks


Title: Re: Thoughts on a second hand EV
Post by: phoooby on May 11, 2019, 11:34:57 AM
PLP I assume you mean PCP (Personal contract purchase). ie. deposit, monthly payment followed by a 'balloon' payment to buy or hand back and walk away.

From you description of usage pattern and not knowing your budget, I would suggest a 30kw leaf which seem to be about £13-£17k at the moment. You might get away with a 24kw which would about £3-4k cheaper if the 130 mile trip is a round trip and you can charge at the destination via a 3 pip plug for 8hr etc or if you are prepared to do a public rapid charge if this is available on route or close to your destination.

I am perhaps bias having owned a 24kw leaf but they seem to have fewer problems than the Zoe and you dont have the monthly battery rental. Newer Zoes are available with battery included. I borrowed a 40kw one for a week and was quite impressed. It had about 150 miles range so would more than cover your all your usage. The Zoe is quite a bit smaller than the leaf so I guess it will depend on the variety of dog and amount of luggage.

Kia Soul also seems to be liked by owners but there a fewer around on the SH market.



Title: Re: Thoughts on a second hand EV
Post by: HalcyonRichard on May 11, 2019, 11:41:16 AM
That evezy link looks interesting. Quite tempted to try a Zoe for a bit and see how we get on with it. Shame we would have to go all the way to Bristol but not a deal breaker.

Thanks

I think they will deliver but not sure. There is quite a discussion here :-

https://www.speakev.com/threads/the-evezy-discussion-thread.135610/

Richard


Title: Re: Thoughts on a second hand EV
Post by: todthedog on May 11, 2019, 12:38:43 PM
Watching this thread with interest.

Couldn't convince myself when I did a similar exercise a couple of years back.

So hyundai i10 for the moment.

Not flat in Wales!

Keep us posted on what you deside.

Good luck.


Title: Re: Thoughts on a second hand EV
Post by: renewablejohn on May 11, 2019, 01:45:17 PM
I am waiting for the C ion batterys to become mainstream before I dip my toe in the market. Just cannot justify Lithium as a technology to be supported.


Title: Re: Thoughts on a second hand EV
Post by: MeatyFool on May 11, 2019, 04:38:12 PM
For circa £40 you can buy an ODB2 connector and Leafspy app.  This would enable you to check the health of the Leaf battery.  You know then what you are buying.  Speakev website has useful threads about usage.

I was fortunate.  I bought my 24kwh Leaf just as a whole load of 3 year PCPs came to the end and the Leaf 2.0 was imminent.  I ended up spending £500 less than the equivalent age diesel I part exchanged.

Depending on your mileage, you are likely to save quite a sum on fuel. If you are at all twitchy about your occasional longer trips, bear in mind you could probably hire a car a couple of times a year and still be in pocket if you so choose.

30kwh would be better, 40 kWh if budget allows.  My car is most definitely a second car only.  Gets me to and from work, does short weekend trips for local attractions, but would be useless without the first petrol car.  If I was a bit less risk averse, I might try longer trips using public chargers.  Your movement may vary!

Meatyfool..


Title: Re: Thoughts on a second hand EV
Post by: oliver90owner on May 11, 2019, 08:26:17 PM
Yeah, PCP. whistle

Watch out for vehicles with leased battery.  They were a popular on the Zoe, but on other marques/models, too.  One has the satisfaction that you know you are covered in the event of a failure, but may be paying handsomely for that. MExtra mileage, over the lease contract, can be expensive.



Title: Re: Thoughts on a second hand EV
Post by: Bodidly on May 17, 2019, 03:42:56 PM
Been trying to do my research.

We did one of our regular longer trips the other day and checked out charging options which were mixed. The midpoint charger which may be needed in anything less than perfect conditions looks good. It's a 43 kW charger that is in working order and always available. The only charge point near our destination is a 22 kW but due to problems with tampering is only available during working hours of the shop it's connected too. Probably not a deal breaker as the granny charger will probably suffice at that end.

Now I am mulling the big picture. Think I am right in saying we still use plenty of fossil fuels in our electricity generation in the UK.
These are some numbers from internet searches but they may well be off or double counted so looking for more expert numbers.

From what I can make out fossil fuel is converted to electricity at between 33%-50% efficiency

10% is then lost in transmission

The Renault Zoe charges at around 70% efficiency

EV car is 60% efficient

Can some bright spark work out what the total efficiency is?

An ICE car is around 20% efficient which at face value sounds dreadful but looking at the numbers above I am not so sure.



Don't get me wrong I am all for EVs running off renewables but while we are still using loads of fossil fuel in the UK is burning it in a car such a bad place? For us, we can probably charge one from some more PV and a nifty charger I saw called a Zappi that can divert excess PV to the car battery.

Thoughts on the above?




Title: Re: Thoughts on a second hand EV
Post by: renewablejohn on May 17, 2019, 04:34:08 PM
Been trying to do my research.

We did one of our regular longer trips the other day and checked out charging options which were mixed. The midpoint charger which may be needed in anything less than perfect conditions looks good. It's a 43 kW charger that is in working order and always available. The only charge point near our destination is a 22 kW but due to problems with tampering is only available during working hours of the shop it's connected too. Probably not a deal breaker as the granny charger will probably suffice at that end.

Now I am mulling the big picture. Think I am right in saying we still use plenty of fossil fuels in our electricity generation in the UK.
These are some numbers from internet searches but they may well be off or double counted so looking for more expert numbers.

From what I can make out fossil fuel is converted to electricity at between 33%-50% efficiency


Dont forget the efficiency of getting the oil out of the ground transporting to refinery converting to petrol or diesel then distribution to the petrol station. Nothing like comparing apples and pears.
10% is then lost in transmission

The Renault Zoe charges at around 70% efficiency

EV car is 60% efficient

Can some bright spark work out what the total efficiency is?

An ICE car is around 20% efficient which at face value sounds dreadful but looking at the numbers above I am not so sure.



Don't get me wrong I am all for EVs running off renewables but while we are still using loads of fossil fuel in the UK is burning it in a car such a bad place? For us, we can probably charge one from some more PV and a nifty charger I saw called a Zappi that can divert excess PV to the car battery.

Thoughts on the above?





Title: Re: Thoughts on a second hand EV
Post by: Countrypaul on May 17, 2019, 04:38:00 PM
Based on your figures, it suggests that a Zoe would be 13-19% efficient - but it is very easy to get the figures out of context.  It may well be that a ICE is only 20% efficient, but it could be only 10% depending on what the trip is. Just looking at efficiency of the car also does not give a reflection on the energy used, for example, a 38Ton lorry might be 30% efficient on a run up and down the motorway, whilst the BEV might only be 12% efficient on the school run so the ICE comes out better! The energy used however would tell a very different story.

Too easy to get carried away wth efficiency figues and miss the real picture.

On the sort of journeys you are looking at you need to compare the energy used by the ICE and that used by an equivalent BEV.  Also bear in mind that the fossil fuel used to produce electricity tends to be predominately gas which gives out proportionally less CO2 than petrol/diesel and the pollutants it gives out, eg. NOx, hydrocarbons, CO etc. also tends to be away from city centres.  

The efficiency of CCGT power stations is also around 62% from a quick google search, with national grid losses at 8% and DNO losses from 3-10%

I think the cost of producing the petrol/diesel is also around 6kWh/US gallon , so about 1.5kWh/Litre.


Title: Re: Thoughts on a second hand EV
Post by: Bodidly on May 17, 2019, 04:39:54 PM



Dont forget the efficiency of getting the oil out of the ground transporting to refinery converting to petrol or diesel then distribution to the petrol station. Nothing like comparing apples and pears.





Not trying too hence me asking for other opinions just when I discovered the Zoe lost 30% during charging it got me wondering about the whole picture. Also this bit is the same either way "Dont forget the efficiency of getting the oil out of the ground" but not seen numbers on refining but yes they should be in there.


Title: Re: Thoughts on a second hand EV
Post by: GarethC on May 17, 2019, 04:48:20 PM
https://www.carbonbrief.org/factcheck-how-electric-vehicles-help-to-tackle-climate-change?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+carbonbrief+%28The+Carbon+Brief%29

Guardian did analysis too a couple of years ago.


Title: Re: Thoughts on a second hand EV
Post by: kristen on May 17, 2019, 06:49:38 PM
From what I can make out fossil fuel is converted to electricity at between 33%-50% efficiency

Even if your, current, only source of electricity is from Fossil Fuels won't it get greener during your ownership of the car?  Can't achieve that with an ICE :) and can't you choose to use Green Juice from the start?

Quote
The Renault Zoe charges at around 70% efficiency
EV car is 60% efficient

Those seem really low to me, compared to what I remember reading ... but I may have mis-remembered (unless Zoe is less efficient than average EV for some reason?)

Not very empirical, but someone in Australia put a gallon in a generator and charged their Tesla ... and then got more miles than a (reasonably efficient) ICE car did on a gallon.

Generator runs at optimum, constant, Revs - whereas ICE car has to have emission controls that work across all Revs etc.

https://electrek.co/2018/02/16/tesla-model-s-charged-diesel-generator/

I think the other factor is that switching from ICE to EV creates market pressure. There must be some improvement to come for EVs with economies of scale, some of which will be improvements in greening; charging the EV overnight soaking up base-load etc.


Title: Re: Thoughts on a second hand EV
Post by: MR GUS on May 17, 2019, 07:00:48 PM
We bought a nissan leaf (Acenta) last year with 8k on the clock for just over £8k (plus buyer comission) via BCA you can join easily (free) & peruse / keyword search for all electric vehicles in forthcoming auctions...

Athough winter wasn't harsh it did affect estimated mileage for a couple of weeks, "marginally" ...my wife though, smug as hell because of pre-heating & zero need to scrape ice in the morning at 6.45am ..the neighbours love its stealthy silent nature too.

Pre-cooling not so good as you have to remember to set it on the dash before you leave the car, or else it may struggle to really cool when needed, we adore it though.

Wife very happy about the car, not too happy about charging infrastructure, she atypically gets 4.2 miles per kilowatt hour, we mainly charge from home, but travel to milton keynes alot as a result, SO many charging points there, rapid charge, few hours in the dome, drive back guilt free, just shy of 100 miles round trip (inc roadworks).

Sounds like a 24 kWh leaf would do you just fine, pick up is terrific, we drive in max regen, (have to remind wife to change the settings on the dash so the brakes get cleaned occasionally).

No drama charging, just not as much as to give her confidence to really drive long distances into the unknown, though that is a remnant of the smaller battery & her mindset clashing, we have never gone into turtle mode in 10,000 miles of motoring in a year.

cheap is possible, we are on a renewable tariff, charge slowly (95% of time) & it works, mile from a windfarm so you can be sure its all coming from there regardless :garden

Incidentally, since I don't think i'm getting my licence back I picked up an A-B ebike from Bristol yesterday (416 watt hour battery & my large frame) ..cycled across london in peak traffic to catch my train north(ish) "twas a breeze" (unlike 20 years ago on a regular MTB) ...the bike lanes help, but the attitude of drivers seems to have improved also, quite civil.

SO many Prius hybrids I stopped counting, ZERO pure e.v. ...just seems a mental defecit to be carrying a stonkingly heavy car engine in such heavy sub 20 mph stop start traffic!
Rode bike home from the station in 30 minutes, no grating knee-cap, just a sore butt.

It sounds like you are the perfect contender for a smaller battery leaf... we've had a granny cable through the wall & been fine.
No way could we live with the battery rental of renault, which is what put us off a twizy sometime ago, now the twizy is like hens teeth.

My kid (now 15) got home from school, & has nicked my "new" ebike,  ..pedalled off shouting "you're going to have to learn to share this Dad" ..she's got more confidence on the main roads in a 20 minute ride as a result of the instant pick up, despite it being a heavy framed bike.

Makes me think that 15.5 mph for bikes with disc brakes ought to be 20 -25mph instead.

We need to get more law makers onto & into E-transport of all kinds to speed lower carbon transport uptake along.  



Title: Re: Thoughts on a second hand EV
Post by: brackwell on May 17, 2019, 07:24:31 PM
The Nat Grid leccy is c250grms CO2/kwh  and diesel in a ICE is c300grms CO2/kwh

A EV does 4mls /kwh and a ICE does 1ml/kwh (at best) ie a EV produces 20%-25% the polution of CO2 but also NO PATICULATES which kills people, no benzene fumes which are carcogenic,less brake dust pollution.

EV is much superior driving experience, costs less than the ICE equivalent and pollutes a lot less. We need it now!

Ken


Title: Re: Thoughts on a second hand EV
Post by: GarethC on May 19, 2019, 07:34:50 AM
https://insideevs.com/features/350266/electric-cars-vs-gas-cars-emissions/

Links to study by union of concerned scientists that doesn't look too biased.


Title: Re: Thoughts on a second hand EV
Post by: kristen on May 19, 2019, 08:39:18 AM
There are countless arguments of course ...

One of them is that pollution for EVs is "out of town" - at power generation site etc. - so that driving in town is then not polluting the air.


Title: Re: Thoughts on a second hand EV
Post by: Bodidly on May 19, 2019, 08:49:54 AM
https://insideevs.com/features/350266/electric-cars-vs-gas-cars-emissions/

Links to study by union of concerned scientists that doesn't look too biased.

Bias is why I was just trying to follow the efficiency of energy generation to home without getting into EV V ICE cars debated which inevitably brings in bias. Thought there should some spot-on data for this.


Title: Re: Thoughts on a second hand EV
Post by: GarethC on May 19, 2019, 11:22:07 AM
Interestingly, one of the difficulties I used to have with this kind of calculation (also for heat pumps vs gas heating) is that I used to feel that I should use the emissions from a coal fired power station in them when feeding in the emissions associated with the leccy used.

The argument was that additional marginal demand for leccy represented by my EV or heat pump was likely to be met by coal (all other things being equal). Now, it really is near as damn it fair to say that marginal demand will be met by gas. That transforms the calculations by more tha halving the leccy carbon intensity. And is why I'm very very seriously looking at getting a heat pump. Even with an SPF of just 2.5, conservative assumption, it would lop a chunk off my heating emissions.


Title: Re: Thoughts on a second hand EV
Post by: samss on May 25, 2019, 03:52:58 PM
Zoe 60% relates to granny charger, aka 10a max.

IIRC nearer 90% for 7kw home charger, or 22/43kw fast charger.

I can take some measurements on single phase at home at different current settings.


Title: Re: Thoughts on a second hand EV
Post by: samss on May 27, 2019, 07:23:56 PM
Right, just to update my previous reply. I've repaired my prototype 32amp single phase charger, using openEVSE and a Eastron Modbus Meter in the same enclosure. This matches on the "Watts" category very closely with the car's diagnostic measurement, so i trust its accuracy.

I retrieved the DC kW from the car, and other data from the Modbus meter.

10a is the usual pilot for a "Granny Lead", 16a is the usual pilot for a 3.6kw home charger (rare now) 32a is the usual pilot signal for a 7kw home charger (usual). Unless using a smart charger like the Zappi or OpenEVSE with a clamp meter for following solar output, then varying pilot signals aren't usual.

The DC is only to one decimal place in kw, so to nearest 100watt, the AC is to the watt, so could be 50watt either way.

I am assuming all of the DC is going in to the battery, it's not really clear but it does measure a negative figure when you turn the ignition on, so assume its the battery shunt.

Pilot Signal (amps)

6a  55% Efficiency  0.78pf
10a  76% Efficiency 0.92f
16a  84% Efficiency 0.98pf
32a  88% Efficiency  1pf

Power factor isn't really relevant for most people on grid i don't think, but included it anyway.

The Zoe follows the pilot signal change within a second or two, which is quite cool. Really would love a bigger solar array and have it charge off grid as much as possible,