Saturday, January 12, 2013

Should you buy a full electric vehicle

Price and data listed here are average and used for comparative purposes only

Maker             Model      Price      Battery      Weight     Range      Economy     

Mitsubishi
I-Miev
38,000
usd

16 kWh
($8000)
1080 kg 112 kms 30 kW-hrs
/160 kms

Nissan
Leaf
40,000
usd
24 kWh
($12,000)
1521 kg 117 kms 34 kW-hrs
/160 kms

Ford
Focus
40,000
usd
23 kWh
($12,000)
1674 kg 122 kms 32 kW-hrs
/160 kms

Chevrolet
Volt
30,000
usd
16 kWh
($8000)
1715 kg 56 kms 36 kW-hrs
/160 kms


Tesla
Roadster
140,000
 usd
53 kWh
($28000)
1235 kg 400 kms 36 kW-hrs
/160 kms

Purpose : We will assume that you purchase a vehicle to get you from A to B within your budget and circumstance. For a family saloon the choice would be the Nissan Leaf, Ford Focus and the Chevrolet Volt. The Mitsubishi I-MiEV would be for the short range city commuter while the Tesla will be for those with deep pockets.

Price : Full EV's are priced around US$40,000. This price is about twice the price of a standard vehicle. If you deduct the cost of the battery the price would be comparable to that of a standard vehicle.

Range : For the full EV range per charge is around 120 kms. This is a function of the battery size and weight of the vehicle. This makes the EV suitable only for the short commutes. The Chevy Volt also has a gasoline engine making it suitable for use as a standard family car. The Tesla has a range of 400 kms but the price makes it suitable for those who needs a vehicle as a personality statement.

Battery : This is the bane of all electric vehicle. The lithium ion battery is expected to last 7000 cycles and at 100 kms per cycle the standard EV should do 700,000 kms over it's useful life. I am very sceptical that this figure can be achieved. Even half the distance in my reckoning would be a stretch.

When the time comes for battery replacement the cost of replacement will most probably be more than the vehicle is worth. The argument that with economies of scale the cost of batteries will come down. This is a fallacy. Both Lithium and Yttrium the rare earth metal used in it's production are exotic metals.  If demand increases price will increase due to supply constraints. Economies of scale does not apply.

Putting a life span of 8 years or even 10 years for a vehicle is a turn off for vehicle owners. A typical vehicle goes through several class of owners. First are those who purchase the vehicle new and would use it foe 2 to 3 years selling it then for half it's value. Then comes those who would purchase a near new vehicle also keeping it for 3 to 5 years. Finally those who would purchase a cheap used vehicle expecting to spend a little more for maintenance and fuel economy.

The problem here is that with the cost of battery replacement the people in the second group ie those that would purchase a near new vehicle will find that their vehicle has no resale or even trade in value.

People in the third group will not have the money for a new battery. Those in the first and second group can afford a new battery but they would not settle for a 5 to 6 year old vehicle. It is for this reason that EV's will have great difficulty in finding a mass market.

Hybrids : Hybrid vehicles have taken off and will soon displace the standard petrol vehicles. For one the batteries used are Nimh to facilitate the fast charge and discharge and cost only around $2000 to replace. Many early hybrids (Prius NHW10) are still running 16 years later thanks to HV battery reconditioning technology coupled with HV battery augmentation with the Power Jockey allowing weaker HV batteries to work comfortably with the vehicle systems.

Already we see Renault and Mitsubishi giving up on EV's after spending more than $4 billion in development. Are electric cars dead? I believe not. We cannot keep burning fossil fuels as we are basically fowling our own nest.

"How many times must you be socked in the face before you admit that global warming is causing the wild fluctuations in our weather and 1 billion cars is the main cause ?" When we deem that the cost to us in infrastructure destruction and rebuild is too high we will place a premium on burning fossil fuels. It is when we decide to do this that I see a come back of the EV's with better battery technology and clean energy to drive it.

Car makers turn to petrol 
Electric cars will flop despite subsidies


Thursday, January 3, 2013

Fuel octane rating and vehicle performance

About a couple of years ago I had an argument with a motor diagnostic specialist about the use of hi octane fuels. I have always used 91 octane in all our hybrids. His opinion was that we will get 5% improvement in fuel economy if we changed to 95 or 98. I have always resisted this change as the Prius is not a particularly high compression engine and therefore I see no added advantage. In any case the extra cost would cancel out any improve performance.

Chris Read has this to add which to me settles the matter.

Nearly all modern cars (certainly Japanese cars) learn various characteristics, a key one of which is octane rating, any car that has learnt a particular grade will probably react very badly when a fuel at the other end of the scale is used.

If I had a pound for every time somebody had told me they only buy a particular brand or grade of fuel 'because the car suddenly performs badly if another type of fuel is used' then I would be a rich man.  They have all been right in the short term and wrong in the long term.  Every scientific test I have ever seen (last one was performed by the Consumer Association in the UK for the Which? magazine, you can't get any more independent than that) concludes that standard unleaded (91 RON in the UK) gives the best value for money and there is no discernible difference between fuel brands (Shell, BP, etc.).

I choose a RON rating that is within the suitable range for the vehicle and stick to it, avoid premium or performance fuels as the extra costs in producing and marketing such fuel make it uneconomic to use (once the car has learnt to use 'basic' fuel).  If you want to change fuels then disconnect the 12v battery for a few minutes just before changing fuels to force the car to re-learn quickly, this will stop the warning lights.


(If you can, watch the long and short term fuel trim on a scanner (most will do OBD2 or E-OBD), for a few minutes after the 12v is re-connected and the car started.  The long and short fuel trims learn at the same pace for a while, then the long term gets heavily weighted by previous data and changes very very slowly.  It's this slow change that makes the car run so badly for a while after fuel is changed and sometimes puts an error light on.  Without a 12v disconnect, after a few days of learning the long term fuel trim adjusts enough to put the error light off and the cars running improves as it matches the fuelling better, happens much quicker with a 12v disconnect.)

Regards,

Chris.