Eschew Obfuscation: Category Electric Vehicles

Long Distance EV Driving

Max Dunn — Fri, 03 Feb 2012 09:59:00 -0800

Some people envision that a network of public charging stations would allow EVs to make long trips. However, I am not so sure.

Even though the Leaf claims a 100 mile range, this is only possible with non-freeway driving. For the normal American driving habits, the EPA gives a range of 73 miles which is in-line with my Leaf experience. Also, if I drive hard on the freeway, then my range can be as low as 60 miles.

This means that when driving a far distance, you could drive for about an hour, then have to stop and DC fast charge for 30 minutes. Since the DC fast charge fills up the battery to only an 80% level, the next leg would be even shorter. Driving the 400 miles LA to from San Francisco normally takes about 6 and a half hours in a gas car, but an EV would require at least 6 recharges and take about 10 hours. Doable, but not very efficient.

EV Public Charging Cost

Max Dunn — Tue, 31 Jan 2012 07:58:00 -0800

David Herron asked a question today on LinkedIn about the cost to charge an EV at a public station. For those of you not on LinkedIn, here is the answer.

Currently, most public charging stations are free, but you sometimes need to pay for parking. For instance, when I am in SF, I usually park my Leaf at Pier 27 and pay $15 ($10 at night and weekends) to park. A 2-hour charge costs them about 75 cents in electricity, so it is cheap for them. But, they have 2 spaces reserved for EVs and these are often empty and so overall, they are probably losing money.

A company called 350Green is installing charging stations at Walgreens. Walgreens pays for just part of the cost and 350Green will make revenue by selling charging subscriptions for about $70 a month. Coulomb Technologies is also planning on charging too, at about the same rate.

Why does it cost $70 a month? Well it is expensive to install a charging station. EVs take about $35/month in electricity so a $70 subscription leaves $35 for equipment and profit. A networked charging station costs about $2,000 but installation can be expensive depending on how far the power lines need to run. So figuring another $2,000 for installation means a total cost per charger of $4,000. Most people that buy a monthly subscription probably can’t charge at home (maybe they live in an apartment and park on the street) so they will probably want to plug-in while they are at work. This means there can only be one subscription per charger, which will take about 5-years just to pay for the charger and installation before the company makes any money at all.

EV Electricity Costs With PG&E

Max Dunn — Sat, 01 Oct 2011 09:49:00 -0700

Figuring out how much electricity your electric vehicle (EV) will use is pretty easy. From the wall, 1kWh of electricity will power the Leaf about 3.5 miles (and a similar amount for other EVs). So for a normal 1,000 mile a month usage, it would take about 300kWh of electricity each month (rounding up).

This should add about $35/month for electricity at the average price of $0.11 per kWh. However, for most users it will push them up into higher tiers and be at least twice that. For us, we went from a $70/mo electric bill to $170/mo!

But wait, it gets more complicated. EV owners are required to contact PG&E and go on a special E-9 time-of-use rate plan.

The great thing about this plan is that off-peak, you can charge your EV for $0.05 to $0.06! The bad thing about this plan is that the bottom tier only goes up by 30% and then all times have higher costs. For instance, after 130% of base usage is reached, off-peak charging goes to $0.16 and then at 200% goes to $0.20!

We just switched over a few months ago and are still analyzing our bill, but it looks like it was reduced from $170 to about $120. We think with some reduction (turn off those lights kids!) and shifting our dishwasher to after midnight we can get it down to about $100, which means the EV will cost about $30 per month. Just where it should be!

Li-Ion Battery Cost Breakdown

Max Dunn — Fri, 04 Feb 2011 19:58:00 -0800

It would seem obvious that lithium is the most expensive part of a li-ion battery. However, it turns out that lithium contributes only 10% to 14% of the battery cost, while the separator is responsible for 40% to 60%! Here is the breakdown of how each material in a li-ion battery contributes to its overall cost:

Anode: Made from carbon, 5% to 15%
Cathode: A metal oxide, 5% to 11%
Electrolyte: A lithium salt in an organic solvent, 10% to 14%
Separator: Made from polyolefin, 40% to 60%

It is very surprising that the plastic polyolefin is the most expensive part of a li-ion battery!

(From the Pike Research blog post Lithium-Ion Battery Materials: Japan Dominates in the EV Era

Public EV Charging Station Ratio?

Max Dunn — Tue, 14 Dec 2010 11:57:00 -0800

In previous analysis, I relied on the Better Place estimates that initially there should be 4 public charging stations per electric vehicle (EV) and that this number could drop to 2 to 1 as the EV population grew.

However, new numbers from Pike Research suggest that we only need 1.15 to 1.3 charging stations per EV.

While these numbers are all guesses, it is important for anyone trying to determine how much revenue they could expect from installing EV charging stations since at 4:1 there will be a lot more unused charging time at each station than at 1.15:1.

(Source: Pike Research – Charge Spotting: Determining the Right Mix for Public EV Access)

Making Money From Public EV Charging Stations

Max Dunn — Tue, 12 Oct 2010 17:14:00 -0700

Electric vehicles (EVs) will soon be available in large numbers and will need to be charged daily. This is no problem for half of the US population that can charge at home, but the other half that park on the street or in apartment complexes will need public charging stations. Is it possible to make money from EV public charging stations?

There are several ways to do this. One is to add a percentage surcharge over the price of electricity used (although this maybe prohibited by some PUCs), another is to charge a fixed fee every time a charging station is used and a third is to charge a monthly fee.

Nissan Leaf to Retain 40% of Value

Max Dunn — Tue, 12 Oct 2010 08:39:00 -0700

There has been some concern that electric vehicles (EVs) will not hold their value as much as gas powered cars because of the high cost to replace the battery pack. However, a new report by CAP (a leading Europe-based vehicle valuation firm) forecasts that the Leaf will retain 40% of its value after 3 years and 30,000 miles. Their reasoning:

The Leaf should have a shallower depreciation curve than conventional cars; the electric motor has fewer moving parts than an internal combustion engine so when mechanical issues and wear and tear begin to affect other cars, the Leaf should still be running well.

For my Leaf, I ordered the SL option package and the fast charger but got a discount from North Bay Nissan. With tax and everything, my out-the-door cost will be about $37,000. However, with the $7,500 federal rebate and the $5,000 state rebate, my net cost will be $24,500. So if it retains 40% of its original price, the real depreciation after 3 years would be about $10,000. Not bad!

(Source: AutoBlog Green)

Electric Cars Best Way To Reduce U.S. Oil Dependency

Max Dunn — Thu, 30 Sep 2010 07:11:00 -0700

A new report from Rice University confirms what I have been saying for a long time – electric vehicles (EVs) are the best way to reduce America’s oil dependency.

The report found that if only 30% of vehicles are electrified by 2050, oil usage would be reduced by 2.5 million barrels a day and carbon emissions cut by 7% – even if the electric generation mix remains the same as today. They also found that a carbon tax of $30 a ton would actually increase US dependence on foreign natural gas!

So even if our government is not able to get its act together and institute a comprehensive renewable energy policy, the widespread adoption of EVs will do the job anyways.

(Source: AllCarsElectric.com)

3.2 Million Plug-in Electric Vehicles to be Sold Worldwide by 2015

Max Dunn — Wed, 01 Sep 2010 19:30:00 -0700

Pike Research released a new report “Plug-in Electric Vehicles” which estimates that by 2015, sales of electric vehicles (EVs) will total over 3 million worldwide with over 800,000 sold in the U.S. While I think these numbers are conservative, they are higher than Pike predicted just a year ago.

Around the World With No Emissions

Max Dunn — Tue, 24 Aug 2010 09:52:00 -0700

Five teams from four continents started the ZERO Race on August 16th in an attempt to drive their electric vehicles (EVs) around the world in 80 days using only renewable energy – which means they will produce no emissions at all!

It is not a race about speed, but the start to creating a greener planet and a better place to live for future generations by making small, efficient vehicles popular. The team with the smartest, most efficient, most reliable, most usable and most popular concept will be the winner.

Zapino Li-Ion Conversion: Cost

Max Dunn — Sun, 22 Aug 2010 09:25:00 -0700

I have been putting off this post about the cost of converting my Zapino electric scooter to lithium batteries because it was certainly more than I would have liked to spend. But anyone that is considering doing the same conversion should know about the cost, so I am going to bite the bullet and put out the numbers.

Thundersky 40ah batteries, balancers and charger: $1,476
Battery box conversion: $200
Total: $1,676

Whew, that wasn’t as bad as I thought!

I considered saving $300 by not buying the charger, but I am glad that I got it. Besides being 3 times faster than my current charger, it also works great with the battery balancers by providing pulsed charging at the end to equalize all the batteries.

Also, with care these batteries should provide about 60,000 miles of use, which works out to about $0.03 per mile. So even though the purchase price was high, the lifetime cost will be about 1/3 that of the cheaper lead-acid batteries all while providing higher performance.

Zapino Li-Ion Conversion: First Ride

Max Dunn — Mon, 02 Aug 2010 16:08:00 -0700

Putting in lithium-ion batteries in my Zapino scooter was a big investment and I am still a little nervous about how well they will work and how long they will last. But I just went for my first ride on my newly converted Zapino and came back with a big smile on my face after covering 18 miles!

I had planned on just riding to the library and back which would have been about 6 miles, but it felt so good after I got there that I decide to ride down to Los Gatos along the long stretch of Hwy 9. The entire trip, the acceleration remained peppy as the voltage on the batteries never sagged below 60 volts. I could also feel the difference that the 80 lb lighter weight made in acceleration and handling. I passed one radar speed sign and it said I was doing 37 MPH. The whole way the voltage of each battery pack remained very similar, which was a good sign.

I am estimating that with the new lithium batteries and lighter weight, I should be able to get about 40 miles out of my newly converted Zapino. Next up, a longer trip to test this range!

Elite Power Thundersky Balancers

Max Dunn — Mon, 02 Aug 2010 15:40:00 -0700

This post is very specific about the new Elite Power Solutions Thundersky battery balancers. I am posting it in order to help other people that might have the same questions I did about how to mount them.

First off, here are the old battery balancers that Elite Power Solutions provided for Thundersky batteries:

Notice that the circuit boards have a short wire attached. This makes it easier to mount and allows both LEDs on the board to be seen. However, some might think that the wires look a little sloppy.

Here are the new battery balancers:

Zapino Li-Ion Conversion: Battery Box

Max Dunn — Fri, 30 Jul 2010 08:06:00 -0700

I finally did it – I got Li-Ion batteries for my Zapino and started the conversion! This will reduce the battery weight from 150 lbs to 70 lbs and increase the range from about 20 miles to about 40 miles. While quite a bit more expensive than lead-acid AGM batteries, they will last more than 3 times as long so the lifetime cost will be less.

The first challenge I ran into is that the batteries are slightly taller so the two in front wouldn’t fit. The fix for this was to take the Zapino to my mechanic and have him reweld the battery box to add about 2 inches to it. This worked fine, but does reduce my clearance so I will need to be more careful about speed bumps and going up curbs.

Before

After

Batteries Mounted

Toshiba SCiB EV Battery Lasts Longer Than 4 EVs

Max Dunn — Tue, 06 Jul 2010 16:55:00 -0700

Battery life has always been a big concern of electric vehicles (EV). Being the most expensive element of an EV, if they don’t last long it would drastically increase the cost of owning an EV. Early ead acid batteries last about 300 to 500 cycles, which is good for only a year or two of driving. Lithium ion (Li-ion) batteries are much better, lasting about 1,500 cycles and with a 100 mile range, this would give a life of 150,000 miles, or about the same as the life of the car.

However, Toshiba has been working on a new battery technology with a greatly increased life span of 6,000 cycles. This would give an EV a lifetime range of about 600,000 miles, or enough to swap into 4 different EVs! Imagine that you buy an EV and 10 years later it is starting to fall apart, but you can use your batteries for your next EV greatly reducing the cost of your subsequent EVs.

Another advantage of the SCiB technology is that it is safer and can withstand fast charging. Now word on price or when it will be available, but they are working with Mitsubishi and several other partners to bring it to market.

Source: AutoBlog Green: Toshiba partners with Mitsubishi for development of li-ion SCiB EV batteries

Shale Oil Extraction Energy - Put In EVs Instead

Max Dunn — Sun, 28 Mar 2010 07:17:00 -0700

There was an interesting article today on The Oil Drum today titled Using heat to refine kerogen from oil shale. The basic idea is that in order to get oil out of shale you need to heat it up, but then the oil can flow away and water can flow in. So first, it is necessary to create an ice wall around the site.

However, both the freezing and the heating takes tremendous amounts of energy. The article states:

“It has been suggested that the technology would need a dedicated power source of some 1.2 gigawatts, in order to yield a production of 100,000 bd.”

Let’s look at these numbers: 100,000 barrels of oil contains 4.2 million gallons of oil and if this were all converted to gas and used in standard cars that get 20 miles per gallon, it would power cars 84 million miles.

However, a 1.2 GW power plant would produce about 28 million kWh of electricity per day and if used for a standard electric vehicle (EV) which gets about 3 miles per kWh (plant to wheels) then it would power cars for 86 million miles.

So why spend all that effort and energy to extract oil from shale when the same amount of energy would power EVs farther?

Lithium batteries - $450 kWh

Max Dunn — Thu, 11 Mar 2010 19:43:00 -0800

Lithium-ion (Li-ion) battery prices are dropping rapidly and automakers are already seeing quotes of $450 per kWh for next year.

This is a huge drop from the historical price of $1,000 per kWh and even better than this year’s price of $650 per kWh.

In addition, this new report by Deutsche Bank not only predicts that performance of Li-ion batteries will double in the next 7 years, they also predict the price will decline by another 50% in the next 10 years.

At $450 kWh, the 16kWh battery in the Chevy Volt would add only an additional $7,200 to the price of the car which will pay for itself in the gas savings after 90,000 miles – or sooner if gas rises above $3 per gallon.

(Source: GM-Volt.com. Report Reveals Lithium-ion Battery Prices Already Dropping Steeper Than Expected.)

EV Charging Controller

Max Dunn — Tue, 09 Feb 2010 21:33:00 -0800

Electric utilities are are scared of plug-in hybrids and battery electric vehicles (EVs) – scared they will all plug-in to recharge after work on a hot summer day and bring down the grid.

As long as EVs are charged off-peak, there is more than enough power to charge about 160 million EVs without building any new power stations. Below is an outline of some of the ideas I have about making sure EVs don’t charge during peak times but instead, actually help the electric grid.

Nissan Leaf Electric Car

Max Dunn — Thu, 03 Dec 2009 08:23:00 -0800

The Nissan Leaf electric car is making a 22 city tour and stopped at Stanford yesterday for a lecture and viewing of the car (although we didn’t get to drive it). The car looked – well, like a car – and the most of the information was standard electric car stuff. For instance, a 24kWh Li-ion battery pack with a 80 kW (106 HP) motor will propel it up to 100 miles with a top speed of about 90 MPH. They covered the usual stuff about 95% of all trips in the US being less than 100 miles and 80% of the charging will be at work and home. The also estimated that it will save about $1,400 a year in gas costs, which just about covers the cost of the battery over the 10-year life.

They are working hard to be the first affordable EV. They expect to start taking orders in Spring of 2010 and start delivering cars later that year.

For me, the most valuable information from this lecture is that they are collecting zip codes of people interested in the Leaf on the web site and sharing these statistics with the electric utilities and some utilities are starting to upgrade the transformers in the areas that will likely have a lot of EVs. They also mentioned that some places can be very difficult to get permits to install the charging stations in personal garages. They said that the Mini-EV program gave up trying to setup the electric car program in New Jersey because of these problems. The reason this was interesting to me is that it points to a possible business opportunity!

For more information, see my detailed notes.

Smaller Cars Are Safer

Max Dunn — Mon, 03 Aug 2009 09:29:00 -0700

What would you think is the safer car to drive – the Toyota Camry at 3300 pounds or the Ford Explorer at 4800 pounds. Would you believe the lighter Camry?

Safety statistics show this to be true. For every million Camrys on the road, 41 Camry drivers perish in crashes and an additional 29 people die in accidents involving Camrys. However, for every million Ford Explorers on the road, 88 Explorer drivers die and it kills 60 other people. So driving an Explorer is twice as dangerous as driving a Camry!

Why is this? The bigger Explorer can’t avoid accidents as easily as the nimbler Camry and is more prone to rollovers.

So next time someone says they feel safer in a big car, point out that the smaller car is actually safer.

References:

Why a Scooter and the Prius Get the Same MPG

Max Dunn — Sat, 25 Jul 2009 07:57:00 -0700

A friend of mine recently got a 400cc Suzuki Burgman scooter and loves it. He gets 53 MPG which is pretty good, but realized that it was about the same as a Prius that gets 48 MPG. “Why is this?”, he asked. The Prius weighs about 3000 lbs while the scooter is only 400 lbs.

Let’s look into this.

Regenerative Breaking

Even though the scooter is a lot lighter, the Prius captures about 50% of the energy when breaking and uses it to accelerate. So this brings the effective weight of the Prius down to 1500 lbs.

Wind Resistance

Even though the scooter has a frontal area 4 times smaller than a Prius, a scooter is not very smooth going through the air. It has a coefficient of drag (Cd) of about 0.9 versus about 0.26 for the Prius. Adding this up, the total drag coefficient (Cd x A) for the Prius is 6.24 and the scooter is 5.4. This means that the scooter takes almost as much energy to overcome wind resistance as the Prius!

Motor Efficiency

Small engines are not very efficient, while Prius engines are very efficient.

Conclusion

Add them up: the extra weight is not as significant because of regenerative breaking, the wind resistance is about the same and the motor is much less efficient. Given all this, it is not surprising that the scooter and the Prius get about the same gas mileage!

Oil Production Energy vs EVs

Max Dunn — Mon, 29 Jun 2009 08:54:00 -0700

One of the factors that we often forget when comparing Electric Vehicles (EVs) to gas powered cars is that it takes a lot of energy to extract and refine oil into gas.

For instance, in California it takes about 14kWh of electricity to get a barrel of oil out of the ground, and about double that to refine it. About half a barrel of oil gets refined into gas, which means this 20 gallons of gas takes about 21 kWh of electricity.

It also takes a lot of natural gas to refine oil, and if this natural gas was used instead to produce electricity, it would produce about another 20 kWh of electricity.

Therefore in a typical gas car that 20 gallons will last 400 miles. But if we just left that barrel of oil in the ground and used the electricity and natural gas for an EV instead, we could go about 120 miles or about 30% of the distance of the ICE car.

So the next time a comparison is made between the efficiency of gas cars and EVs, remember even before the gas gets into the tank, we are already giving up 30% of the energy that we could have used to power an electric vehicle.

Tesla Efficiency

Max Dunn — Thu, 19 Mar 2009 11:39:00 -0700

I admit it – I am a numbers geek. I love to play around with numbers and think about them, and no more so than with electric vehicles. So imagine how happy I was too see some fantastic numbers about the Tesla Roadster!

The first of these graphs shows how much energy it uses at different speeds. The fact that energy goes down to a certain point is not surprising – all cars have a sweet spot where they operate most efficiently – but what is surprising that it is about 20 MPH versus about 55 MPH for gas cars. Another interesting point is that at 65 MPH the Tesla uses about 280 Wh per mile. This is measured from the battery to the wheels, so adding in the charging losses will decrease it to about 3 miles per kWh, which is the figure I normally use.

Li-Air Battery - Fill-er up!

Max Dunn — Thu, 05 Mar 2009 10:11:00 -0800

A lithium air (Li-air) battery with a novel structure is looking very promising for use in battery-powered vehicles.

One problem with battery-powered vehicles (and an argument for hydrogen fuel-cells) is that it takes a while to recharge the batteries. While this is fine for city driving (since the batteries can be recharged overnight) it makes it tough to drive a long distance, like driving from San Jose to ski at Lake Tahoe.

This Li-air battery could solve the problem of long charge times by allowing service stations to replace the liquid electrolytes and metallic lithium cassette, allowing battery-powered cars to be driven continuously.

Then the metallic lithium can be electrically regenerated from the used liquid electrolyte making the process sustainable.

This Li-air battery could prove very useful in making battery-powered vehicles more practical.

(Reference: AIST Develops New-type ‘Li-air Battery’)

Hydrogen Hype

Max Dunn — Tue, 24 Feb 2009 16:17:00 -0800

Natural Capitalism is a terrific book. But it got one thing wrong – its hope for hydrogen cars. Dan Neil at the LA Times put it well: "Any way you look at it, hydrogen is a lousy way to move cars." (Ref) Here are a few of the reasons why hydrogen won’t work:

Hydrogen is only an energy carrier. It is not an energy source. (Ref)
Hydrogen is made from fossil fuels. And this will likely be the case for the next several decades. (Ref)
Hydrogen production produces CO2. (Ref) For instance, the Honda FCX Clarity hydrogen car indirectly produces 176g CO2/mile while the Toyota Prius hybrid produces less CO2 at 167g CO2/mile. (Ref)
Hydrogen cars are very expensive. The FCX Clarity costs several hundred thousand dollars and it will take many years to even drop below $100,000. (Ref)
Hydrogen leaks. A hydrogen car left in an airport parking lot for two week could lose 50% of its hydrogen. (Ref )
Hydrogen isn’t very efficient. (Ref) Only 20% to 25% of the energy needed to make hydrogen can be recovered. (Ref) Even using renewable energy, battery powered vehicles can still go 3-times further on the same electricity than hydrogen vehicles. (Ref)
Hydrogen cars fill up slowly. It currently it takes about 30 minutes to fill up a hydrogen tank. (Ref)

In the long-term, maybe the challenges with hydrogen cars will be solved. However, it is also likely that the few remaining problems with battery powered vehicles will be solved too. Physics will then remain firmly on the side of battery powered vehicles and it will be easier and more efficient to just transfer renewable electricity over power lines to charge battery vehicles than to convert the electricity to hydrogen, ship it, and convert it back into electricity again.

Lithium Supplies Are Adequate

Max Dunn — Mon, 02 Feb 2009 21:32:00 -0800

There has been some worry that there wouldn’t be enough lithium production to meet the rising demand for Li-ion batteries for electric vehicles. However, a recent study has concluded that due to the recession, demand for lithium will drop and there will be adequate supplies at least through 2020.

(Reference: TRU Presentation Lithium Supply & Market)

Cost of Reducing CO2 with Electric Vehicles

Max Dunn — Fri, 23 Jan 2009 07:33:00 -0800

There are some questions about whether electric vehicles (EVs) actually reduce the amount of CO2 emitted, especially when electricity is produced by coal. However, we have seen that EVs in clean energy states produce only 1/6 as much CO2, and even in the worst case, produce no more than a regular gas car.

Providing more evidence of this, a new study by Boston Consulting Group not only shows how much less CO2 electric vehicles produce, but also puts a figure on how much this costs:

While this report shows that the cost of reducing CO2 with electric vehicles is not cheap, costing between $7,000 and $14,000 to reduce CO2 in half, the CO2 savings far surpass anything possible with advanced gas (ICE) engines. And the CO2 emissions caused by electric vehicles is only going to get lower as electric power generation becomes cleaner and the premium for electric cars will continue to fall as batteries become cheaper.

(Reference: The Comeback of the Electric Car)

Crazy RAV4-EV Prices

Max Dunn — Thu, 08 Jan 2009 10:32:00 -0800

The prices that people are paying for RAV4-EVs are a little crazy. Last year, several sold on eBay for over $45,000.

Today there was an auction for a 2003 RAV4-EV with 97,000 miles – which means the battery pack will need to be replaced at a cost of about $15,000. Nevertheless, the sale price was $32,600, so the total cost will be over $47,000 – crazy!

I mean the RAV4-EV is a great car, but it makes more sense to wait for another year or so when the new electric vehicles like the Chevy Volt will be available and will likely be less than $40,000.

Real Electric Vehicle Costs

Max Dunn — Mon, 05 Jan 2009 11:42:00 -0800

Interested in what it really costs to operate an electric vehicle? Here is what one RAV4-EV owner estimated his costs to be, including replacing the battery pack:

First 115,000 miles:

$30,000: Original price minus $20,000 rebate
$5,000: Charger, solar panels, some grid power
$4,000: Tires, brake pads, minor dent removals, AAA, rear glass, seat covers, registration
$6,000: Insurance
$45,000: Total, or $0.39 per mile

Next 120,000 miles:

$15,000 battery pack replacement
$3,000 electricity
$5,500 tires, registration and others
$4,000 insurance
$27,500 total, or $0.23 per mile

The takeaway from this is not just that the total per mile cost of an electric vehicle will be lower than a regular car, but also that replacing the battery pack can be done economically.

Source: RAV4-EV Archives (registration required)

180,000 Battery Miles

Max Dunn — Mon, 24 Nov 2008 07:44:00 -0800

One of the arguments against electric vehicles (EVs) is that the batteries won’t last very long and are expensive to replace. However, even the 10-year old NiMH batteries in RAV4 EVs can last up to 150,000 miles and we now we have test results showing that Li-ion batteries can last over 180,000 miles.

Since batteries can now last longer than the car itself, this argument can finally be put to rest.

Zapino Lithium Battery Update

Max Dunn — Wed, 15 Oct 2008 10:52:00 -0700

I just talked to Bob in customer service at Zap. He said that they are testing Lithium (Li-ion) batteries for the Zapino scooter right now and that they should be ready in 4 to 6 months. The cost will be between $1,500 and $2,000 and will include the batteries and charger, but no battery management system (BMS).

So for now, the best option will probably be to use Thunder Sky batteries from Elite Power. They have a package of 20-40Ah batteries and charger for $1600 that should work well in the Zapino. While half the weight of the current lead-acid battery pack, they are a 1/2 inch higher so there might be some rework needed to fit them in.

Converting Trucks to Hybrids - HEVT

Max Dunn — Wed, 23 Jul 2008 15:24:00 -0700

At Plug-in 2008, Andy Grove presented his vision of converting 10 million SUVs, trucks and vans to electric hybrid operation in the next 4 years. Many people in the audience doubted that this goal was achievable, and wondered if the technology to convert an existing vehicle over to hybrid electric operation was even feasible.

However, a company that was exhibiting at the show did exactly this. Hybrid Electric Vehicle Technologies based in Chicago had on the floor a Ford F-150 truck that they had converted to electric hybrid. They did this by leaving the gas engine alone and adding an electric motor to the back of the rear differential. Then the put a 12kWh battery pack behind the seat and used a controller that would regulate the power to the gas and electric engine to achieve hybrid operation.

The F-150 conversions are currently very expensive running $60,000. However, they hope to get the price down a lot as their volume of conversions increase.

Andy Grove should invest a lot of money in HEVT because their technology might be the key to achieving his vision.

EV Charging Infrastructure by Coulomb Technologies

Max Dunn — Wed, 23 Jul 2008 10:57:00 -0700

Electric Vehicles (EVs) will have limited range at first due to battery limitations. To increase their range, they will use “opportunity” charging, which basically means trying to find a plug wherever they are.

To help with this, Coulomb Technologies announced at Plug-in 2008 their smart charging infrastructure for plug-in vehicles. One of their offerings is the Smartlet Charging Station so subscribers can charge their EV at any Smartlet station using a supplied smart card.

Let’s hope that Coulomb is successful and receives plenty of funds to continue operations while EV usage ramps up. These charging stations will be one of the keys that will make EVs successful.

CARB ZEV Standard to be Raised

Max Dunn — Tue, 22 Jul 2008 11:24:00 -0700

Many of us EV advocates were disappointed by the ZEV mandate revisions that CARB enacted this year. So we are glad to hear that at the Plug-in 2008 conference today, CARB board member Dan Sperling said that he agreed that the revisions this year were too complex and too soft and next year they expect to simplify them and also increase the number of vehicles required – possibly by an order of magnitude. Wouldn’t that be great!

Why Can't Hobbyists Buy A123 Batteries

Max Dunn — Tue, 22 Jul 2008 10:49:00 -0700

Another interesting tidbit of information that I got from Elizabeth from A123 Systems at the Plug-in 2008 conference was why A123 doesn’t sell batteries to hobbyists for use in electric vehicles. Her answer: liability.

A123 is worried that someone will put together an unsafe vehicle and then A123 would be sued when it catches on fire or someone gets hurt. This extends also to organizations like CalCars that is working on plug-in hybrids. So A123 only supplies batteries to OEMs and manufacturers where they can be sure the batteries will be used in a safe way.

Why PHEV Engines Always Turn On

Max Dunn — Tue, 22 Jul 2008 10:40:00 -0700

One downside to current plug-in hybrid electric vehicles (PHEV) is that the gas motor always turns on when first starting out. At the Plug-in 2008 conference I asked Elizabeth from A123/Hymotion why this was and she said that the engine needed to turn on for about 57 seconds when first starting out to warm up the catalytic converter, otherwise the car wouldn’t pass smog tests. It is too bad that on short trips the gas engine still needs to turn on, but at less than a minute this shouldn’t waste too much gas.

EEStor UltraCaps - Too Good To Be True?

Max Dunn — Wed, 09 Jul 2008 15:56:00 -0700

If EEStor can achieve what they claim, it will blow open the electric vehicle market which is currently held back only by battery technology. Here is what they claim:

For a 52 kWh unit, an initial production price of $3,200, falling to $2,100.
No degradation from charge/discharge cycles
4-6 minute charge time assuming sufficient cooling of the cables.

Currently, a lithium battery pack this size would cost more than $30,000, would last less than 2,000 cycles and takes at least a couple of hours to charge.

However, EEStor is a private company and is not releasing much information to be able to verify their claims. Let’s hope that they are successful!

(Ref: http://en.wikipedia.org/wiki/EEStor)

eVolvo - Electron Hog

Max Dunn — Mon, 23 Jun 2008 11:30:00 -0700

You have heard of a “gas hog”? Well my eVolvo is an electron hog!

Most electric cars get between 2 and 4 miles per kWh. The ones that are light and streamlined and have efficient AC motors with regenerative breaking get the best mileage – and my car is none of these. It is a heavy car with a big DC motor and no regenerative braking. It does have a lot of zip, but at the cost of poor electron mileage.

Battery to wheel, I get about 2.5 miles per kWh. This is based on my maximum range so far of 25 miles, the battery pack of 15 kWh maximum, and a Peukert effect that reduces the useable energy from the lead-acid AGM batteries to about 10 kWh.

However, the Soneil 1206S chargers that are being used are not very efficient, probably around 75%. That combined with charging efficiency of the batteries which is probably around 85% gives a charging efficiency of only about 64%. So from the wall to the wheels I am getting about 1.6 miles per kWh. This figure is consistent with the data I have been collecting:

Miles	kWh	Charge Time	Miles/kWh
22.2	14	–	1.6
6.6	4.3	–	1.5
4.6	3.4	6 hrs	1.4
13.3	8.4	17 hrs	1.6
18.3	11.9	–	1.5

eVolvo Specs

Max Dunn — Fri, 20 Jun 2008 06:49:00 -0700

For those of you wondering what is in my eVolvo, here are the specs:

Batteries: Deka AGM 8A31DT 105AH @ C/20. 144 volts: 4 batteries in front, 8 in back
DC-DC converter 55 amp: IOTA DLS-55
Auxiliary battery: Deka Gel 8GU1H 32AH
Charger: 12 – Soneil 1206S 3amp (one on each battery)
Motor: Advanced FB-4001a (19 HP continuous, 85 HP peak)
Controller: Auburn Scientific PWC600-144 Kodiak water cooled
Brake vacuum: Thomas 107CDC208
Belt: A/C, Steering, Alternator

25 Watt Fuel Cell - Only $5,000

Max Dunn — Wed, 11 Jun 2008 19:26:00 -0700

With all this talk about fuel cells, I have been wondering if it is possible to actually buy one. Here is one I stumbled across a reformed methanol fuel cell that puts out 25 watts. With the standard 12 oz cartridge of methanol, it will produce power for about 7 hours. One drawback is that it takes between 12 and 30 minutes to start-up, not very convenient if you need to get someplace quick. However the real kicker is the price – $5,000! If you wanted enough of these to power a car which takes about 15,000 watts, it would cost over $3 million! Or course this is a methane fuel cell and not a hydrogen one, but it provides another reason to believe that fuel cells are not the answer to the future of transportation.

Book Review - Zoom, The Global Race to Fuel the Car of the Future

Max Dunn — Fri, 06 Jun 2008 19:03:00 -0700

ZOOM: The Global Race to Fuel the Car of the Future
by Vijay Vaitheeswaran

I wanted to like this book – I really did. With a name like "Zoom" and the promise to show the car of the future, I was excited to read it. But in the end, the book turned out to be at best a dud, and at worst misleading and harmful to the future of transportation.

Easy CO2 Calculation for Vehicles

Max Dunn — Fri, 06 Jun 2008 17:05:00 -0700

Sometimes you will hear that electric vehicles produce more CO2 than gas vehicles, however, this isn’t true. Let’s look at an easy CO2 calculation to see why.

Burning a gallon of gas creates 20 lbs of CO2. So a car that gets an average of 20 MPG produces 1 lb of CO2 per mile. Ok so far?

Electric cars get an average of 3 miles per kWh and 1 kWh creates an average of 1.3 lbs of CO2. So an electric car produces about 0.4 lbs of CO2 per mile. So electric cars produce only about 40% as much CO2 as gas cars. Easy, right?

eVolvo - My Electric Car

Max Dunn — Wed, 04 Jun 2008 14:04:00 -0700

I finally did it – I got an electric car!

We had been considering a Miles NEV, but were concerned that even after tweaking it to go 35 MPH (rather than the 25 MPH it is supposed to go) that we would still get run over when driving on streets where the speed limit was 40 MPH or higher. The Miles also would have cost close to $20,000, and even then it was pretty minimal – vinyl seats, manual crank windows and no air-conditioning. So when a converted 1995 Volvo 850 came up for sale nearby for $14,000 we jumped on it!

Powering Electric Vehicles

Max Dunn — Mon, 02 Jun 2008 08:34:00 -0700

One question that is often asked is that if we start to have a lot of electric vehicles, won’t this strain our electric system and require us to build a lot of new electric power plants?

The answer is no – at least at first. The reason is that electric usage goes down considerably at night. By simply charging at off-peak times, then we can use electricity from the plants that would have otherwise been idle.

Let’s look at the math. An electric vehicle consumes 1 kWh from the wall socket for every 2-4 miles driven. The average car is driven about 30 miles per day – so the average daily energy needed per car is only 10 kWh. If these vehicles are charged over 10 off-peak hours, the average power consumption per car is 1 kW. Since California has 25 GW of spare off-peak electric capacity, this can power 25 million electric cars in California alone.

This is just a rough calculation, but the same conclusion was reached in a detailed analysis which found that 84% of all cars in the US could be powered by the existing electricity infrastructure.

Gas vs Electric Motor

Max Dunn — Sat, 31 May 2008 16:27:00 -0700

Which do you think provides more performance by weight and size – a gas motor or an electric motor?

You are right if you said an electric motor. Here is a picture of an electric motor that provides twice the performance of the gas motor, yet is much smaller and has only 1 moving part!

(Reference: EVDrive BMW Project)

RAV4-EV Sold for $70,000

Max Dunn — Wed, 28 May 2008 08:33:00 -0700

There certainly a lot of excitement over electric cars these days. A 2001 Toyota RAV4-EV with over 47,000 miles sold on eBay for almost $70,000! (The selling price listed was $89,000 but this was an illegally retracted bid and the seller confirmed that it was sold for $69,850.)

It was in good shape with only minor scuffing on the left bumper and had an HOV stickers so it can drive in the car pool lane, but $70k seems like a lot of money for an electric car with almost 50,000 miles. Hopefully next year we will start seeing brand new electric cars closer to $40,000.

If you still are dying to get one, there is another RAV4-EV for sale on eBay and the bidding is currently at $50,000.

AGM Battery Charging - Temperature Dependent

Max Dunn — Fri, 23 May 2008 19:00:00 -0700

As we have seem, the biggest per mile cost of running an electric vehicle is not the electricity, it is the battery depletion. So it is important to maximize the life of your batteries. One trick that works with all battery techologies is to take short trips and recharge after each one. By minimizing your depth of discharge (DOD) you will maximize the total energy that the batteries will deliver over their life.

Another very important factor is to charge the batteries correctly. Especially for sealed lead-acid batteries like gel or AGM, correct charging is critical. Deka states that if their batteries are continuously charged with a voltage that is only 0.70 volts over the proper charging voltage, it will reduce the battery life by 60 percent! This is because if sealed batteries are overcharged, they will dry out and there is no way to replace the lost moisture. It is likely that all sealed lead-acid batteries will suffer from this, not just Deka batteries.

Here is the kicker: the proper charging voltage varies depending on the temperature. It ranges from 15.10 volts when it is below 40 degrees 13.60 volts when it is above 120 degrees. And it is not good enough to just measure the air temperature, instead it is important to measure the temperature of each battery since they will often be warmer than the outside air.

So unless your charger or BMS has a temperature probe on each battery, it is almost guaranteed that the batteries are not being charged correctly and that their potential life span will be reduced.

Ford EV Ranger Cost Analysis

Max Dunn — Wed, 21 May 2008 11:19:00 -0700

BlueSky Motors in Sacramento periodically sells EV Ford Rangers on eBay.

When I contacted them about the reserve price for a previous EV Ranger, here is what they said:

The reserve on the vehicle is $26,998 + License, Calif. sales tax, doc fee, and registration. The total cost with a PSC charger ($600.00) ends up close to $29,000. You can call for a test drive – (916) 929-7508 ask for Scott.

Paying almost $30,000 for a Ford Ranger seems pretty expensive – is there a way to justify this? One way is to think about the extra cost as just “pre-paying” for your gas.

The gas 1999 Ford Ranger gets a combined mileage of 16 MPG, so this is about $0.25 per mile at $4 per gallon. Assuming electricity will cost $0.05 per mile, you will save $0.20 per mile with the EV Ranger. (The EV Rangers NiMH batteries will likely last for the life of the car, or about 150,000 miles, so you don’t need to worry about battery replacement costs.)

So one way of looking at the extra $20,000 that this EV Ford Ranger costs is that you are just pre-paying for gasoline at $4 per gallon for the next 100,000 miles and after that, it is like getting free gas. And when gas goes up to $6 a gallon or more, this will seem like a real bargain!

Hill Climbing in EVs

Max Dunn — Mon, 19 May 2008 08:42:00 -0700

When driving an electric vehicle (EV), it is important to know how far you can go on a full charge. On flat ground, the range will be pretty consistent and the only variable will be if you are driving around town or on the freeway. But how will your range be affected when you are driving up a hill?

This is an important question to me because I like to go surfing in Santa Cruz which is about 30 miles away and requires a climb of 1500 feet over a mountain range.

As a rule of thumb, you can add 10 miles for every 1000 feet you climb. So to take the Santa Cruz example, the peak is 15 miles away and a climb of 1500 feet, so it would actually take 30 miles of energy to get to the peak.

Going downhill of course, won’t take as much energy and will actually add some energy if you have regenerative braking. So the total trip to Santa Cruz is likely to take about 37 miles worth of energy.

RAV4 owners have reported that it takes less energy to climb a hill, only 6 miles per 1000 feet. One owner reported driving to Mt. Baldy which was 20 miles away and a climb of 6000 feet. He used about 60 miles worth of charge to get to the top. However, coming back down he added 20 miles of charge, so the round trip only took 40 miles of charge, or only the linear distance disregarding the climb. Ref

Bottom line is that while you need to be aware that it takes extra energy to climb hills, EVs can handle them with no problem.

Zapino Batteries Weakening

Max Dunn — Wed, 14 May 2008 11:10:00 -0700

While Altairno batteries have demonstrated 25,000 cycles, my Zapino batteries are starting to weaken after less than 500 shallow cycles.

This was evident in a ride I took today to Los Gatos to get a new battery for my MacBook. (Yes, even the lithium-ion battery in my MacBook gave out after less than 300 cycles! But this was likely just a manufacturing problem, not an inherent limitation.)

I knew the Electier batteries in my Zapino batteries were getting weak, so I rode in the “economy” mode the whole way, accelerated slowly and rode 25 MPH or less. There were some small hills but I took it really easy going up them. Nonetheless, by the time I was approaching home, the needle was dipping into the yellow upon acceleration and even starting to get in the red. The entire ride was 14 miles, and I probably could have nursed it another 3 to 5 miles, but this was still only about half of the 30 mile range that we got when the Zapino was new.

Altairnano Batteries - 25,000 Cycles

Max Dunn — Mon, 12 May 2008 18:45:00 -0700

The electricity to power an electric vehicle costs very little – usually around 3c per mile. A bigger cost is the wear-and-tear on the batteries, which will cost 8c a mile or more.

For instance, if an electric car has a range of 75 miles with a 25kWh lithium-ion battery pack that has a life of 2,000 cycles, then the car could go 150,000 miles on the battery pack. If the batteries cost $25,000, this adds about 17c per mile to the cost of operating the car in addition to the electricity.

But what if the batteries lasted longer – much longer? Then the total cost per mile would be a lot lower.

For instance, lets say that instead of 2,000 cycles you could get 25,000 cycles out of the batteries. Maybe these batteries cost twice as much, but this would still bring the cost per mile down to about 3c per mile.

Well it appears that Altairnano might have done this. In their recently released 2007 annual report, it states that in January 2007 they completed 25,000 deep charge/discharge cycles of their batteries and they still retained over 80% of their original charge capacity.

The batteries are not cheap – it appears they are selling them for about $2,000 per kWh, about twice what other lithium-ion batteries sell for. But if they can really go 25,000 cycles in the field, it will be an exciting breakthrough!

Hydrogen 13 Times More Expensive Than Electricity

Max Dunn — Mon, 12 May 2008 08:59:00 -0700

Here is another illustration of how expensive hydrogen is. Popular Mechanics looked at how much it would cost to drive across the country in vehicles using different types of fuel. As a baseline, a car getting 33 MPG would cost $213 (with fuel at $2.34/gallon). A hydrogen fuel-cell vehicle would cost $804, while a battery electric vehicle would cost only $60!

Popular Mechanics: Fuel of the Future

RAV4-EV 146,000 Miles and Still Going

Max Dunn — Fri, 25 Apr 2008 08:33:00 -0700

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?

NOVA Car of the Future

Max Dunn — Wed, 23 Apr 2008 08:29:00 -0700

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

Hydrogen Fueling Station: 10 Times Less Efficient

Max Dunn — Sat, 12 Apr 2008 13:21:00 -0700

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)

Zapino Battery Report - 1000 miles

Max Dunn — Tue, 11 Mar 2008 16:18:00 -0700

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.

Farting Along With Air Cars

Max Dunn — Fri, 07 Mar 2008 16:32:00 -0800

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.

Electric Vehicle Battery Costs Per Mile

Max Dunn — Thu, 28 Feb 2008 20:44:00 -0800

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.

What is a "Moped"?

Max Dunn — Thu, 28 Feb 2008 20:07:00 -0800

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.

Scooters in the Bike Lane?

Max Dunn — Thu, 28 Feb 2008 10:36:00 -0800

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?

Bike Riding for Errands

Max Dunn — Tue, 12 Feb 2008 12:30:00 -0800

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!

Hydrogen Powered Vehicles are Not Viable

Max Dunn — Tue, 05 Feb 2008 17:46:00 -0800

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:

Battery Electric Vehicle User Experiences

Max Dunn — Mon, 04 Feb 2008 10:10:00 -0800

Ron Freund, past Chairman of the Electric Auto Association, took a survey of 116 RAV4 -EV owners to see how they liked driving a battery electric vehicle (BEV) in general, and in specific, how their experience with the RAV4-EV has been. This is a great reference for anyone interested in how a BEV performs in the real-world. Some of his conclusions are:

Users frequently commented that the RAV4 has been the best car they ever owned
The RAV4-EV dependability is remarkable
The technology is working, no more research is needed
It is a tragedy that the choice for BEVs does not exist in the market today

Living with a BEV: A Survey of User Experiences

Vehicle-to-Grid (V2G)

Max Dunn — Wed, 30 Jan 2008 16:20:00 -0800

What is with this vehicle-to-grid (V2G) stuff? Why is everyone so excited about it? I already showed how using batteries to store energy at night when it is cheap and then use it during the day doesn’t make sense economically¹.

However, this is only part of the picture. It turns out that electricity generation is very complicated, in large part because there is no real storage on the electrical grid. Think about this: what happens when the power plants on the grid don’t produce enough electricity? There will be brownouts or blackouts, both of which are bad. But what happens when they produce too much electricity? Where does it go? Well, actually, since there is no real storage on the grid, it can’t go anywhere, so this is bad.

Which Alternate Energy Vehicle is the Most Efficient?

Max Dunn — Thu, 24 Jan 2008 17:33:00 -0800

There are several better energy alternatives to power cars than using gas. The top ones are hydrogen, air or battery. However, it turns out that there are big differences in the efficiencies of these technologies. For 100MJ of input electricity, this is how far each of these cars could go: [18]

133 km: Lithium-ion battery vehicle
46 km: Compressed air car
42 km: Fuel cell vehicle

So it turns out that battery electric vehicles are 3 times more efficient than either compressed air or fuel cell vehicles!

Can Battery Backups Make Money?

Max Dunn — Wed, 23 Jan 2008 10:12:00 -0800

I don’t have a lot of confidence in PG&E. It seems that every time we have a big storm, our power goes out. Once, it took 3 days for them to get the power back on! So I have been considering installing a battery backup system for my house to get through these power outages.

If I install a battery backup system, I was wondering if it would be profitable to charge up the batteries at night when electricity costs are low, at $0.05/kWh, and then use it during the day when electricity costs are high, at $0.11/kWh to $0.29/kWh [9]?

The Trouble with Lithium

Max Dunn — Wed, 09 Jan 2008 11:39:00 -0800

It turns out that lithium is not very abundant or easy to mine, and that the price is going up. In this paper, the author even argues that there is not enough lithium available in the world to convert all cars over to plug-in hybrid (PHEV) if we expect to use lithium batteries in them:

The Trouble with Lithium – Implications of Future PHEV Production for Lithium Demand

Lithium Silicon Nanowire Battery - 10 Times As Much Energy!

Max Dunn — Wed, 09 Jan 2008 10:16:00 -0800

An revolutionary new technology is being developed by Stanford researcher Yi Cui that could could generate 10 times more energy from lithium-ion batteries. The trick is that instead of using carbon anodes, they use silicon nanowires because silicon can hold large amounts of lithium atoms. The nanowire technology allows these small wires to swell to four times their normal size without breaking. [1]

When Cui’s paper was originally submitted six months ago, they had only achieved 30 charge-discharge cycles. Since that time however, Cui’s team has pushed the battery through 1000 cycles. [2]

Ultimately, these batteries should be cheap to build. However, they are probably 5 years away from being commercialized. [3]

In reality though, the “10 times more energy” figure is just the theoretical charge capacity increase in the silicon anode, so a real production battery won’t see that much improvement. But even if it improves the overall energy density of a lithium ion battery by 2 or 3 times, that would still be very significant.

[1] Nanowire battery can hold 10 times the charge of existing lithium-ion battery

[2] New Nanowire Battery Life Reaches From iPods to Electric Cars

[3] GM-Volt.com: Interview with Dr. Cui, Inventor of Silicon Nanowire Lithium-ion Battery Breakthrough

Electric Vehicles Produce a Lot Less CO2

Max Dunn — Sun, 30 Dec 2007 09:35:00 -0800

When I talk about how clean electric vehicles are, people sometimes ask if they really do reduce greenhouse gases since burning coal to produce electricity creates a lot of CO2. My standard answer to this question is that even in the worst case, electric cars are twice as clean as gas powered cars. However, while reading an article in Forbes about vehicle-to-grid (V2G) systems. I realized that in general, electric cars are much cleaner than even this.

This article had an interesting chart that said electric cars produce about 1.1 tons of greenhouse gases a year while gas powered cars produce 6.3 tons – over 6 times more! Let’s see if we can verify these numbers.

The average car is driven 15,000 miles per year and electric vehicles normally get 4 miles per kWh, so it takes about 3,750 kWh of electricity a year to power an electric car. In California, the mix of electricity production produces about 0.6 lbs of greenhouse gases per kWh so this would produce 2,250 pounds, or 1.1 tons of greenhouse gases – right on the money with the Forbes chart.

A gas car, on the other hand, produces about 1 lb of CO2 for every mile driven (based on producing 20 lbs per gallon and getting 20 mpg). So 15,000 miles would produce 15,000 lbs of greenhouse gases, or about 7.5 tons – which is more than the Forbes estimate of 6.3 tons (maybe they are using a higher mpg).

So electric cars are even cleaner than I had thought, producing about one sixth as much greenhouse gases as a gas car.

When to Buy an Electric Car?

Max Dunn — Tue, 04 Dec 2007 09:09:00 -0800

That is the question – whether to buy a low-speed electric vehicle now, or wait for a high-speed electric vehicle later? Here are the factors I am looking at:

What type of transportation do I need?
When will high-speed electric vehicles really arrive?
How much will they actually cost?
When will the severe oil shortages start?
Will there be subsidies for electric vehicles?

The short answer is that I am going to buy a low-speed NEV now and wait for later to buy a freeway capable electric car. Here is the long answer:

Grocery Shopping on the Zapino

Max Dunn — Wed, 12 Sep 2007 13:26:00 -0700

Today, I went grocery shopping on our electric Zapino. I was a little worried that I wouldn’t be able to fit all the groceries in the basket and under the seat, so I took a Trader Joe’s bag too and planned to hold it between my feet. However, it turned out that I didn’t have any problems. Here is what I bought:

Large powdered Gatorade
2 – Boxes of cereal
Half gallon milk
Quart of goat’s milk
Jar of mayonnaise
2 – Tamales
Frozen fish
Asparagus
French rolls

As you can see from the pictures, they all fit in nicely! I definitely could have squeezed a few more things in, and then could have filled up the shopping bag and put it between my feet.

Zapino Charging

Max Dunn — Sun, 02 Sep 2007 08:02:00 -0700

After running the Zapino battery all the way down last night, I put the charger on it with the Kill-A-Watt meter to record how much power it would take to recharge. The charging rate started at about 360 watts and then increased to 400 watts. The total power consumed was 2.68kWh.

This is an interesting number and does make sense since the battery pack is rated at 2.28kWh (60v-38ah) and you would expect that there are some losses when charging. Sealed lead-acid batteries typically can be up to 95% efficient and chargers are typically 90% efficient, so combined these numbers lead to the total efficiency we measured of 85%.

Another useful fact about charging is that for every hour that the scooter is being charged, you are adding about 4 miles to the range. (Based on the charger putting out 400 watts, and the Zapino using about 100 wh/mile.) So, for instance, my wife works part time at an office about 18 miles away. So if she is there for 4 1/2 hours, the Zapino will be completely recharged.

Zapino Range

Max Dunn — Sat, 01 Sep 2007 19:01:00 -0700

After the excursion with my wife today where we traveled about 20 miles, I went to go pickup my son at the pool which was a little over 5 miles away. I was still taking it easy in economy mode and staying around 25 mph. However, I did go through the neighborhood where there were a lot of stop signs. Coming back home, we got about 3 miles away and the range indicator starting to drop into the yellow when we accelerated. At 2 miles it was dropping into the red, so I started driving 15-20 mph. At about 1 mile away, the engine cut out because the indicator dropped below the road while accelerating. Coasting to a stop, I turned off the key and back on again and was able to continue. I then starting going really slowly, about 10 mph. The engine cut out a few more times, but we made it home. So i consider that we fully utilized all the available range.

Total distance today 31.2 miles. Not bad!

Zapino Excursion

Max Dunn — Sat, 01 Sep 2007 17:02:00 -0700

Last Wednesday, after weeks of looking around at electric scooters, we finally bought a Zapino and love it! Today, Suzanne and I took a little excursion around town to see if it could carry both of us and to see how the battery would hold up on a longer trip.

The first thing you should know is that it was hot in San Jose today, getting up to 94 degrees. Riding the Zapino was nice because the breeze cooled us off. However, we were worried that it would overheat because we were pushing its 282 lb weight limit with our combined weight of 275lbs. (And no, Suzanne forbids me to break out our weights separately. ;-)

Since we were just out cruising, we were using the energy saving mode which limits the top speed to 30mph. Most of the time, this is plenty fast, but I did kick it into high-speed mode several times going down Highway 9 to Los Gatos.

The Diagnosis light was flashing its 2-3 combination which means that it is overheating, but I just ignored it and kept going

We stopped at a store and looked around for about 5 minutes. When we got back on the Zapino, the overheat protection kicked in and it made us go really slow. This was probably because after stopping, there was no more wind to cool off the controller and it was so hot out anyways. This slow speed was fine since we only needed to ride a block. We then got off again and walked around for about 20 minutes before getting back on the scooter, at which time it had cooled down.

Going home, we continued to take it easy but the “overheating” warning starting flashing again very soon. This didn’t seem to make any difference, although our top speed was a little lower, around 25 mph in the energy saving mode. Just for fun, right before we got home I put it back into high-speed mode and it sped right up past 30 mph, no problem.

I realized on this trip that the diagnosis light is a little annoying. In order to read the flashing codes, you have to look at it continuously for about 5 seconds, which is very dangerous while driving.

Our total outing ended being about 20 miles and the charge indicator was only about halfway down in the green. So we have now confirmed that driving conservatively with a heavily loaded bike can take you at least 20 miles on the Zapino.

Suzanne and I really enjoyed our little excursion on the the Zapino!