Posted by Max Dunn
Fri, 25 Apr 2008 15:47:47 GMT | no comments
RAV4-EV owners have a very high level of satisfaction with their electric cars. In particular, they pleased that their RAV4-EV NiMH batteries are still going strong past 100,000 miles and are only showing signs of slowing down when they start approaching 150,000 miles. As Avi Shai reported on the RAV4-EV mailing list:
Mine is at 146,037 miles. It sure is showing signs of advanced age.
The maximum SOC I see, after full charging, is around 92%. The volt meter movement is almost directly coupled to the accelerator paddle. Even moderate acceleration causes the needle to deep precipitously close to the yellow range. Going uphill is a risky business and I try to stay in the right lane and go slow (60-65 mph) otherwise I get a visit from the turtle.
The car still fatefully does the job it was intended to, and it takes me through my 90+ miles daily commute with no problem (charging at both ends).
So even though Avi’s batteries are definitely worn down, they still get him to work and back, which is a commute of over 90 miles. And this is on battery technology that is over 10 years old. With real-world experience like this, who can still say that battery technology isn’t ready yet to support electric vehicles?
Posted in Electric Vehicles
Posted by Max Dunn
Wed, 23 Apr 2008 15:36:00 GMT | no comments
Last night, NOVA broadcast an interesting and informative show about cars of the future. It includes segments on ethanol, biofuels, hydrogen, plug-in bybrids and electric cars. You can watch it online at:
NOVA – Car of the Future
Posted in Electric Vehicles
Posted by Max Dunn
Sat, 12 Apr 2008 20:33:12 GMT | 1 comment
A new $3.2 million hydrogen fueling station opened in Sacramento last week that has 80kW of solar PV panels are used to produce the hydrogen, so it won’t use any outside energy. Let’s take a look at how efficient this is:
SOLAR OUTPUT:
- 80 kW * 5hrs = 400 kWh per day
WITH FUEL CELL CARS:
- 400 kWh / 65 kWh per kG (Stuart Energy) = ~6 kG per day (AT 5000 PSI)
- 6 kG * 45 miles per kG = 270 miles per day
- 100,000 miles per year
WITH ELECTRIC CARS :
- 400 KWH * 3 miles per kWh (RAV4 EV) = 1200 EV miles per day
- 438,000 miles per year
Considering the solar array probably cost probably cost around $10/watt, or $800,000 out of $3,200,000, the hydrogen “refueling station” cost approximately $2,400,000.
If that money had been used to build $2,400,000 of solar installation plus $800,000 of EV chargers – about 240 kW of solar and 160 EV charger stations – enough for well over a million miles per year (80 cars worth) instead of just a hundred thousand hydrogen fuel-cell vehicle miles (8 cars worth). So the hydrogen fueling station is only 10% as efficient as building solar recharging stations for battery electric vehicles.
(From RAV4-EV Digest, Vol 58, Issue 12, comment by William Korthof of EESolar)
Posted in Electric Vehicles
Posted by Max Dunn
Wed, 12 Mar 2008 00:23:10 GMT | 1 comment
I have put over 1,000 miles on my Zapino since we got it last August, and I was wondering if I needed to get a battery management system (BMS) to keep the batteries going as long as possible. So today, after a pretty long ride where the indicator started to dip into the red, I took off the covers and checked the voltage.
The batteries were labelled:
Electier
Danwant Silicone Power Battery
6-DW-38Ah (12V38Ah)
Before charging, the voltage on all 5 batteries was between 12.58V and 12.61V. During charging, it was from 14.5V to 14.9V. Then about 30 minutes after charging was done, they were between 13.52 and 13.54V. This is very close and within specs, so it looks like the batteries are doing fine and don’t need a BMS, at least for now.
Posted in Electric Vehicles
Posted by Max Dunn
Sat, 08 Mar 2008 00:33:21 GMT | 5 comments
I was trying to explain to my wife how an air car worked, and with a smile on her face she said “So it farts as it moves forward?” Well maybe that sums it up nicely.
But do air cars really make sense? The information from the manufacturers seem like they are the solution to our energy crisis, and to everything else too [1]. But there are several fundamental problems with air cars.
Read more...
Posted in Electric Vehicles, Global Warming, Peak Oil
Posted by Max Dunn
Fri, 29 Feb 2008 04:46:08 GMT | 5 comments
When companies talk about electric vehicles costing pennies per mile in electricity costs to operate, they are being truthful. However, with current battery costs and lifetimes, the battery replacement cost in an electric vehicle will be more than the electricity cost. Let’s look more closely at this.
Read more...
Posted in Electric Vehicles
Posted by Max Dunn
Thu, 28 Feb 2008 19:21:48 GMT | 1 comment
After my stop yesterday by the policeman who thought my electric Zapino scooter was a motorcycle and I shouldn’t be riding in the bike lane, I decided to try to find out more information about what California Motor Vehicle law says about this. I found this interesting “Motorized Bicycle Instruction/Application” from the DMV site that defines a “motorized bicycle” (also commonly known as a “moped”):
- Having two or three wheels
- Fully operative pedals or powered solely by electric power
- Maximum speed of 30 MPH on level ground
- Automatic transmission and a motor with less than 2 gross brake horsepower
The first two requirements are easily met, and for the third, Zap states that it can only go 30 MPH, but the Zapino actually can go a bit faster. Regarding the fourth point it does have an automatic transmission but the 3000 watt Zapino motor puts out about 4 HP, which exceeds the maximum 2 HP allowed for a motorized bicycle.
Based on this, the Zapino is close to being a motorized bicycle, but not quite since it has more power than is allowed. However, since most people want know the conversion between watts and HP, it is not obvious whether the Zapino is a motorized bicycle or not.
Posted in Electric Vehicles
Posted by Max Dunn
Thu, 28 Feb 2008 18:42:50 GMT | 5 comments
A cop just pulled me over on my scooter. I was riding in the bike line – like usual – and there was a bicyclist in the lane so I swerved around him. The cop saw this and said that since I was riding a motorcycle, I shouldn’t be in the bike lane. I explained that the manufacturer stated that it was a moped since it couldn’t go more than 30 MPH and it was all electric and so I should be riding in the bike lane. He said that I was probably going about 35 or 40 MPH (which is probably true) and that I should be riding just outside of the bike lane. However, he seemed a little unsure once I explained that the scooter was electric, so just gave me a warning.
However, this brings up a good question: should electric scooters ride in the bike lane or just outside of it? What is the maximum speed that we should go in the bike lane? In the California Motorcycle Handbook 2007 it says on Page 3:
You may ride a moped in a bicycle lane at a reasonable speed.
So is 30 MPH a “reasonable” speed to ride in the bike lane, or is this too fast?
Posted in Electric Vehicles
Posted by Max Dunn
Tue, 12 Feb 2008 20:32:09 GMT | 2 comments
I should ride my bike more. It is good exercise and saves the environment. However, I don’t like to ride my bike on everyday errands.
I was reminded of this today when I got new tires for our car. Like usual, I threw my bike in the back and rode home after dropping off the car. It isn’t far, about 2.5 miles, but I was hot and sweaty when I got home. I was smart this time and brought a piece of string to wrap around my pant leg. Usually I forget this and wind up getting chain oil on my pant leg.
When the car was ready, I rode back to the shop to pick it up, and I was a bit tired.
So it certainly worked out fine to ride my bike, but it isn’t something that I would normally do. Also, for the same reasons, I don’t think we can expect many Americans to forgo their cars and start doing a lot more bike riding either. Good thing I have my electric scooter to scoot around on!
Posted in Random Thoughts, Electric Vehicles, Global Warming, Peak Oil
Posted by Max Dunn
Wed, 06 Feb 2008 02:15:27 GMT | 4 comments
Regardless of what Bush thinks, hydrogen powered vehicles are not a viable alternative.
First off, hydrogen is not something that can be “mined”, but instead must be produced using other energy sources [1]. With current technologies, electricity from hydrogen fuel cells is four times more expensive than electricity from the grid [2]. Secondly, hydrogen is very difficult to ship and store. Leave a hydrogen car at the airport for two weeks and half of the fuel will be lost due to evaporation [2]. Thirdly, while hydrogen fuel cells are clean, currently hydrogen fuel cells are costly to produce and fragile [3] and only about 50% efficient [4]. Lastly, hydrogen is not very dense so cars would need to have a tank 2-3 times larger than their gasoline tanks [3].
With all things considered, it doesn’t make sense to power cars with hydrogen; instead, just put batteries in the car and use the electricity directly.
References:
Posted in Electric Vehicles