EV disappointment

Battery & Chargers
1

I was all gung-ho to do an EV conversion, as I’m not thrilled with my Prius’ mileage on short rural trips, but I now see that there isn’t much to be gained.

Until an EV is efficient enough to do better than 3mi/kw (or so), my Prius, even at only 45mpg, is cheaper to operate. And from an environmental viewpoint, relocating the CO2 emissions from my tailpipe to a power plant is a marginal improvement, especially if the power plant is coal fired.

Although I’m not very experienced in the EV conversion business, a “cheap” DC motor conversion isn’t going to meet the 3m/kw figure. I think the EV-1 met the number (by a factor of two) but that was pretty sophisticated equipment.

I hope someone can convince me otherwise!

2

there’s plenty of people out there that get closer to 200Wh/mile…with small cars. Motorcycles are even better (closer to 100wh/mile)… so that’d be 5m/kwh

(wh per mile or wh/mile is the standard unit for most ev’s)

I don’t see how its cheaper to operate your prius… sure, a conversion has high up front costs, but when you factor in batteries and energy to charge it for 2-3 years that the batteries last, you’ll spend MUCH less on energy than you would on gas. You can’t count the cost for conversion/controller/etc… you pay to have an electric car. What you need to look at is recurring costs only, not the sunken cost.

Plus, the scrubbers and cleaning that energy generation plans do at their smokestacks is MUCH CLEANER than what we put out of our car. They have to reduce NOx, SOx, COx etc to levels outlined by EPA… its strictly controlled. Our tailpipes are not well controlled and spit out MUCH more. PLUS if you live in an area like me that has lots of greener energy (wind, water) then its much cleaner to drive. Sounds like you need to do some research… just because a plant may be coal fired, doesn’t mean its that dirty… its cleaner than an automobile.

3

I guess I’m confused.

On the recurring cost side,

With my Prius, I average 46-48mpg, which makes my per mile cost about $.04 with gas at $2.

With a 2.5m/kw conversion, the per mile cost is about $.04 with $.10 per KW electricity.

The total cost of ownership is a pretty complicated calculation. I drove all my prior cars at least 300K miles, so assuming the Prius holds, up, thats probably one battery replacement ($3K?), which is ($23K+3K)/300K = $.09/mi.

Let’s say a conversion costs the same $23K, and in the 15 years it takes to get to 300K miles, it needs 5 replacement batteries, (23K+5*8K)/300k = $.21/mi.

The Prius seats five tall adults, has unlimited range. There may be conversions that get way better than the 400w/mi number, but as you say, their either tiny or very expensive technology. There are many Prius drivers that average into the 6o+ mpg, and I understand that Toyota could boost the mileage significantly if they re-programmed the charge/discharge, which would shorten the battery life.

The Prius batteries are warranted for 8 years, but the EV batteries are only good for a much shorter period of time (I didn’t realize their life was as short as you mention).

There are several conventional cars that can get 40-45mpg, which pencil out way better than either the Prius of the EV.

I guess I was just hoping the EV would be a no-brainer, which I don’t yet see.

4

You’re basing a LOT of your argument on assumptions. Most cars (the size of a prius) that I’ve seen converted can get 200-300Wh/mile… check EValbum… I’m talking small to midrange, not the economy/micro sized cars. Trucks might get 400Wh/mile…so, going by 250 as a median value, it’d get you 4 miles on 1kw… and cost you 2.5 cents/mile.

As far as battery life, Lead batteries are cheap… you’re conversion doesn’t need to cost $25k, you can do one for $7-10k with bats easily. Now if you want lifepo4, thats another story. If you want AC thats additional. 25k could get you a nice car with lead and an AC system. If you want lifepo and a series wound system (still a good choice) you could do it for $25k and it’d get better mileage (lighter)

Prius’s don’t have unlimited range, they just have an infrastructure for gas refueling. EV’s have infrastructure, you just need to charge them… so they could be considered just as “unlimited” as the prius… you just have to wait longer to “refuel”

EV batteries if they’re lead are good for 3-5 years if taken care of, I use conservative numbers. If you use lifepo, they’re supposed to get you 2-3 times that life. you might have to replace the pack once in 150k miles on an EV with lifepo. If you use lead, maybe 6 times but at a fraction of the cost of lifepo.

If you don’t think an EV adds up right now, then keep driving the prius, I think its a great little car… hell of a lot better than my Durango… just remember that EV technology is getting way better.

You’re right though, with hybrids available, and the cost of batteries for EV’s not quite low enough, and the range not quite high enough, we have to add everything up for total cost of ownership.

there’s also the environmental impact to consider.

5

I’m new here. So pardon a dumb question. Seems to me you are focusing on cost of fuel and batteries. To be more exact you’d need to include the $$ for mainenance. Beside the trivial oil changes and filters (at $22 every $3K you spend 0.73 cents per mile, you have the major services. I haven’t put paper to pencil, but the more expensive services at 15K or whatever they are for the Prius.

Frankly I wouldn’t consider an EV as an only vehicle because of the range limitations. Seems like it would make sense for a 2 (or more) vehicle family where one could be EV.

The business school type of analysis would have you consider the acquisition cost of the vehicle but I won’t bore anyone with that.

6

There is another factor - the current cars all have CAT’s - my Jeep has 3. The first two are part of the exhaust manifold. $500 aftermarket cheap. The stock one has failed after 110,000. Also, I have 4 O2 sensors. Each is about $100. The 2 before the 2 CATS have failed after 110,000. I would guess the 2 after the CAT are not far behind. SO, $900 just for parts in maintenance, assuming the third CAT does not fail soon. If course, the EPA required Jeep to program the computer to go into “limp mode” so you would not be inclined to ignore the emission maintenance.

I drive 70 miles @ 70 mph round trip to work. A conventional EV will not work. Later this fall I will be doing an EV conversion on my now diesel powered Caravan. I will keep the diesel front drive, and install the EV to drive a rear drive axle from a Caravan that had AWD. This will give me some EV range, and no limit for diesel power.

7

[QUOTE=jgurley;5729]I was all gung-ho to do an EV conversion, as I’m not thrilled with my Prius’ mileage on short rural trips, but I now see that there isn’t much to be gained.

Until an EV is efficient enough to do better than 3mi/kw (or so), my Prius, even at only 45mpg, is cheaper to operate. And from an environmental viewpoint, relocating the CO2 emissions from my tailpipe to a power plant is a marginal improvement, especially if the power plant is coal fired.

Although I’m not very experienced in the EV conversion business, a “cheap” DC motor conversion isn’t going to meet the 3m/kw figure. I think the EV-1 met the number (by a factor of two) but that was pretty sophisticated equipment.

I hope someone can convince me otherwise![/QUOTE]

You should get the Ford Fusion plug-in hybrid. Its quality is equal to the best Toyotas, and has much better technology / mpg. It just did a 1440 miles on a single 17.5g tank of gas, with a full charge. It goes on EV along for almost twice the speed the Toyota can do. Much better car.
http://www.at.ford.com/news/cn/Pages/OneThousandMilesandCountingFusionHybridBreaks1,000MilesonSingleTank,Presseson.aspx