The discharge voltage curves of Li-manganese, Li-phosphate and NMC are very flat, and 80 percent of the stored energy remains in this flat voltage profile. This characteristic assists applications requiring a steady voltage but presents a challenge in fuel gauging. The voltage method only indicates full charge and low charge and cannot estimate the large middle section accurately.
When measuring SoC by open circuit voltage, the battery voltage must be truly “floating” with no load present. Installed in a car, the parasitic load present makes this a closed circuit voltage (CCV) condition that will falsify the readings. Adjustments must be made when measuring SoC in the CCV state by including the load current in the calculation. In spite of the notorious inaccuracies, most SoC measurements rely on the voltage method because it’s simple. Voltage-based state-of-charge is popular for wheelchairs, scooters and golf cars.
Approximate state-of-charge
Average specific gravity
Open circuit voltage
2V
6V
8V
12V
100% 75% 50% 25% 0%
1.265 1.225 1.190 1.155 1.120
2.10 2.08 2.04 2.01 1.98
6.32 6.22 6.12 6.03 5.95
8.43 8. 30 8.16 8.04 7.72
12.65 12.45 12.24 12.06 11.89
While BCI specifies the specific gravity of a fully charged starter battery at 1.265, battery manufacturers may go for 1.280 and higher. When increasing the specific gravity, the SoC readings on the look-up table will adjust upwards accordingly. Besides charge level and acid density, the SG can also vary due to low fluid levels, which raises the SG reading because of higher concentration. Alternatively, the battery can be overfilled, which lowers the number. When adding water, allow time for mixing before taking the SG measurement. The specific gravity also varies according to battery type. Deep-cycle batteries use a dense electrolyte with an SG of up to 1.330 to get maximum runtime; aviation batteries have a SG of 1.285; traction batteries for forklifts are at 1.280; starter batteries come in at 1.265 and stationary batteries are at a low 1.225. Low specific gravity reduces corrosion. The resulting lower specific energy of stationary batteries is not as critical as longevity.
Temperature of the Electrolyte
Gravity at full charge
40°C 30°C 20°C 10°C 0°C
104°F 86°F 68°F 50°F 32°F
1.266 1.273 1.280 1.287 1.294
Adjust Charging Time - It's all too easy to arrive home in the evening, plug your car in and immediately start it charging for the next day's commute. But while you'll know your car will be fully charged when you need it, you may be reducing your car's available range.
That's because most plug-in cars on the market today slowly self-discharge when they've finished charging, either through battery cell balancing or through natural chemical processes occurring within the battery pack. Over time, this practice can slowly affect your car's battery pack. In fact, allowing your car to sit for hours at a full state of charge is something that many automakers—including Tesla, Nissan, Ford and Mitsubishi—advise against.
While it makes a minimal difference, scheduling your charge to finish charging just before you drive it can give you a few extra miles of range— compared to a car that sat with a full battery pack for many hours. (It's also better for the long-term health of the battery, and allows you to make use of cheaper time-of-use rates.)
A battery is a device for storing chemical energy and converting that chemical energy into electricity. A battery is made up of one or more electrochemical cells, each of which consists of two half-cells or electrodes. One half-cell, called the negative electrode, has an overabundance of the tiny, negatively charged subatomic particles called electrons. The other, called the positive electrode, has a deficit of electrons. When the two halves are connected by a wire or an electrical cable, electrons will flow from the negative electrode to the positive electrode. We call this flow of electrons electricity. The energy of these moving electrons can be harnessed to do work -- running a motor, for instance. As electrons pass to the positive side, the flow gradually slows down and the voltage of the electricity produced by the battery drops. Eventually, when there are as many electrons on the positive side as on the negative side, the battery is considered 'dead' and is no longer capable of producing an electric flow.
The electrons are generated by chemical reactions, and there are many different chemical reactions that are used in commercially available batteries. For example, the familiar alkaline batteries commonly used in flashlights and television remote controls generate electricity through a chemical reaction involving zinc and manganese oxide. Most alkaline batteries are considered to be a disposable battery. Once they go dead, they're useless and should be recycled. Automobile batteries, on the other hand, need to be rechargeable, so they don't require constant replacement. In a rechargeable battery, electrical energy is used to reverse the negative and positive halves of the electrochemical cells, restarting the electron flow.
Automobile manufacturers have identified three types of rechargeable battery as suitable for electric car use. Those types are lead-acid batteries, nickel metal hydride (NiMH) batteries, and lithium-ion (Li-ion) batteries.
Lead-acid Advantages: This chemistry has been proven over more than 140 years. Batteries of all shapes and sizes, available in sealed and maintenance-free products, are mass-produced today. In their price range, lead-acid batteries provide the best value for power and energy per kilowatt-hour, have the longest life cycle and a large environmental advantage in that they are recycled at an extraordinarily high rate. (Ninety-seven percent of the lead is recycled and reused in new batteries.). No other chemistry can touch the infrastructure that exists for collecting, transporting and recycling lead-acid batteries.
Disadvantages: Lead is heavier compared to some alternative elements used in other technologies; however, certain efficiencies in current conductors and other advances continue to improve on the power density of a lead-acid battery's design.
Lithium-ion Advantages: It has a high specific energy (the number of hours of operation for a given weight) making it a huge success for mobile applications such as phones and notebook computers.
Disadvantages: More expensive than lead. The cost differential is not as apparent with small batteries for phones and computers, and owners of these devices may not realize that they are paying much more per stored kilowatt hour than other chemistries. However, because automotive batteries are larger, the cost becomes more significant. In addition, currently there is no established system for recycling large lithium-ion batteries.
Nickel-metal hydride Advantages: It is reliable and lightweight. In hybrid vehicles, these batteries have equal to 100,000 miles.
Disadvantages: The metals in the battery are 25 times more expensive than lead. Nickel has been identified as a carcinogen. Hybrid vehicles have not been on the road long enough to allow the batteries to completely prove their projected cycle life. No significant recycling capability exists.
Note: The Advanced Lead-Acid Battery Consortium has helped to develop and test an advanced lead-acid battery powered system that operates at the partial state of charge demands necessary for a hybrid vehicle and recently equipped a Honda Insight with this system. Advanced lead-acid batteries will challenge the more expensive nickel metal hydride system in hybrid vehicles today.
Lead-acid batteries were invented in 1859 and are the oldest form of rechargeable battery still in use. They've been used in all types of cars -- including electric cars -- since the 19th century. Lead-acid batteries are a kind ofwet cell battery and usually contain a mild solution of sulfuric acid in an open container. The name comes from the combination of lead electrodes and acid used to generate electricity in these batteries. The major advantage of lead-acid batteries is that, they are well understood and cheap to produce. However, they do produce dangerous gases while being used and if the battery is overcharged there's a risk of explosion.
Nickel metal hydride batteries came into commercial use in the late 1980s. They have a high energy density -- that is, a great deal of energy can be packed into a relatively small battery -- and don't contain any toxic metals, so they're easy to recycle.
Lithium-ion batteries, which came into commercial use in the early 1990s, have a very high energy density and are less likely than most batteries to lose their charge when not being used -- a property called self discharge. Because of their light weight and low maintenance requirements, lithium-ion batteries are widely used in electronic devices such as laptop computers. Some experts believe that lithium-ion batteries are about as close as science has yet come to developing a perfect rechargeable battery, and this type of battery is the best candidate for powering the electric cars of the near future. A variation on lithium-ion batteries, called lithium-ion polymer batteries, may also prove valuable to the future of EVs. These batteries may eventually cost less to build than lithium-ion batteries; however, at the present time, lithium-ion polymer batteries are prohibitively expensive.
Any electric car that uses batteries needs a charging system to recharge the batteries. The charging system has two goals:
The most sophisticated charging systems monitor battery voltage, current flow and battery temperature to minimize charging time. The charger sends as much current as it can without raising battery temperature too much. Less sophisticated chargers might monitor voltage or amperage only and make certain assumptions about average battery characteristics. A charger like this might apply maximum current to the batteries up through 80 percent of their capacity, and then cut the current back to some preset level for the final 20 percent to avoid overheating the batteries.So here are my proven recommendations on how to take care of these batteries:
For batteries that need maintenance, the battery should be cleaned using a baking soda and water solution; a couple of table spoons to a pint of water. Cable connections need to be cleaned and tightened as battery problems are often caused by dirty and loose connections. A serviceable battery needs to have the fluid level checked. Use only mineral free water, Distilled is best as all impurities have been removed, and there is nothing left that could contaminate your cells. Don't overfill battery cells especially in warmer weather because the natural fluid expansion in hot weather can push excess electrolytes from the battery. To prevent corrosion of cables on top post batteries use a small bead of silicone sealer at the base of the post and place a felt battery washer over it. Coat the washer with high temperature grease or petroleum jelly (Vaseline), then place cable on the post and tighten. Coat the exposed cable end with the grease. Most folks don't know that just the gases from the battery condensing on metal parts cause most corrosion.
If you can soup up a plug-in hybrid electric vehicle(EV), what features would you want? For some fleet managers, turning plug-in hybrids into a source for powering up construction tools or buildings during a blackout is high on the list.
That’ why Pacific Gas & Electric Co. has been helping VIA Motors to convert new General Motors trucks into plug-in hybrids with the ability to export a large amount of power. The utility, the largest in California, envisions sending a bunch of these trucks into the field for routine maintenance work and to deal with emergencies. The amount of exportable power here will be large enough to run hydraulic lifts to send workers up the powerlines to do repairs or serve as backup power for homes while workers fix faulty circuits or transformers, said Dave Meisel, director of transportation services at PG&E. (EV motors)
Hybrid cars offer fuel savings over time – the price of gasoline has risen and will continue to increase at greater rates than the price of electricity – as well as environmental benefits such as lower emissions, he said. As federal and states introduce stricter fuel economy and emission standards, businesses must comply by buying vehicles with more fuel-efficient engines or ones that run on cleaner sources of fuels. But alternative-fuel vehicles also tend to cost more partly because they aren’t made in large volumes, and fleet managers very much focus on the payback period of their investments. (electric motor conversion kits)
Adding the exportable power feature creates additional savings for fleet owners like PG&E, Meisel said. It eliminates the need for buying portable generators that run on fossil fuels, for example. Using the hybrid trucks to reduce the length of a blackout also is an attractive proposition for utilities, which face fines if their customers experience a high number of outages or if they can’t restore power quickly.
“We are looking at broader savings that a lot of people are not looking at,” Meisel said. “When I look at the total operational savings, including fuel savings, the math starts to look really nice.” PG&E has about 9,000 vehicles in its fleet, and roughly 3,100 of them run on alternative fuels, such as natural gas, electricity and biodiesel. (electric car motor)
PG&E has been field-testing two EV trucks since last year and giving the car company feedback about its experience and suggestions for improvements. The utility estimates that the trucks could deliver annual fuel maintenance savings of $7000 per vehicle compared with conventional trucks, said Greg Pruett, senior vice president of corporate affairs at PG&E, during a press event at the Detroit auto show earlier this month when VIA discussed its plans to launch not just hybrid trucks but also hybrid SUVs and vans. VIA plans to convert only GM models, such as the Chevy Silverado, for now.
VIA has developed a powertrain that includes a 24 kilowatt-hour lithium-ion battery pack, which can last up to 40 miles per charge. The gasoline engine is for generating electricity to run the electric car motor, which moves the wheels. The company is putting its technology in brand new vehicles only, not used cars. When VIA Motors showed up at the Detroit auto show, its executives rattled off a list of things that people can do with vehicles that double as power generators, such as catering to outdoor parties and running outdoor concerts.
“Think of a 3-day camping trip where you have unlimited power with the car you drive into the woods with,” said Bob Lutz, a member of VIA’s board of directors and the former vice chairman of GM, during a press conference at the auto show.
The two VIA trucks PG&E has been trying out cost about $400,000 total, Meisel said. The trucks are the early version of what VIA plans to produce commercially later this year, Meisel said. The price for the trucks at “low volumes” should be in the $70,000 range, and it should continue to drop as production increases, he added. (electric motor conversion kits)
VIA isn’t the only company PG&E is turning to for converted hybrids with exportable power. The utility also is considering vehicles from Electric VehicleInternational, which turns beefier pickup trucks to plug-in hybrids. VIA’s truck delivers 15 kilowatts of exportable power and is working on boosting that to 50 kilowatts while Electric Vehicle (EV) International is working on trucks with 100 kilowatts of exportable power. Figuring out a good way to cool the equipment that generates and routes the power becomes a greater hurdle as the size of exportable power increases.
PG&E and other fleet owners are turning to companies that can do after-market conversion for now partly because major automakers have yet to introduce the plug-in hybrid version of the trucks that the fleet owners want to buy.(EV motors) But that day will come if consumers continue to show interest in electric cars (and the prices for them drop). When that happens, companies such as VIA Motors may find it difficult to compete, said Kevin See, an analyst with Lux Research.
“There may be a short-lived window for them to make their mark,” See said. “I wouldn’t expect their businesses to be long-term because of the competition that will enter the market. (EV motor)” MSD
Media Borough has created another reason to make “Everybody’s Hometown” a destination. This time an initiative will make downtown the hometown for owners of electric vehicles (EV).
As only the third known location in Delaware County, Media has inaugurated a charging station in the municipal parking lot next to the Media Fire Department, across from Media-Upper Providence Library and one block from all that State Street has to offer.The borough is participating in a pilot project for EV charging powered by 100 percent Pennsylvania wind energy. Borough officials and Community Energy, Inc. had the ribbon cutting recently, with attendance by representatives of the energy firm, Mayor Bob McMahon, Councilman Eric Stein, Environmental Advisory Council Chair Walt Cressler and several other borough staff member.While the technology includes several cutting-edge elements, charging station operation is fairly simple: pull into the dedicated parking space (lot is between Jasper and Front streets just east of Jackson Street); plug the electric vehicle (EV) into the charger; dine, shop or attend to other borough business. In the span of an hour or two, EVs can be charged enough for at least several dozen miles.“We are pleased to be partnering with Media Borough and the Media Fire Company as this becomes one of the first charging stations in the county,” said Jay Carlis, Vice President of Retail Marketing for Community Energy, Inc. based in Radnor. “This pilot project, funded by the Pennsylvania Department of Environmental Protection, comes early in the electric vehicle transition. At the government level, Media has been a leader in environmental sustainability. This is a great location for residents and visitors.”Carlis said there are electric vehicle (EV) charging stations in Radnor and Wayne and only a handful in the state, placing the borough in the forefront of the technology. To kick off the enterprise, he drove a Chevrolet Volt and hooked it up to demonstrate the virtual plug, charge and go technique.Representatives from Thomas Chevrolet brought a second Volt. Amy Ercolani of Thomas said the dealership has sold several Volts, has one in stock, and expects the manufacturer to supply a small but steady stream of the model, which has a gasoline back-up capability. EVs are available from other automotive manufacturers as well.Running at a 240-volt service, the public station works twice as fast as a charge from, for example, a home outlet which is generally half the volts. An hour charge is expected to cost $3.50 with Community Energy paying a fee to the borough for the actual electric used. The mileage value of a charge varies depending on the electric vehicle and road conditions, not unlike gas mileage. Not surprisingly, there are “apps” which can monitor the charge from mobile devices.In the borough’s view, the station sends multiple signals about the alternative energy commitment which already includes a solar energy grid and wind-generated electricity purchase.“I’m a strong supporter of renewable energy and any electric car conversion. I have solar energy at my home, so I’m not just talking theoretically,” said Stein, liaison to the Environmental Advisory Council. “It’s good for the economy, and good for the environment.” MSD Continued...
General Motors will be collaborating with Spanish energy company Iberdola on a feasibility study to determine the infrastructure needs to support electric car motor vehicles in Europe. Similar studies are underway already between automakers and utility companies in the United States and elsewhere. The two companies have a relationship through other EV projects being run by EPRI. Under examination will be the needs for private, residential, and commercial customers as well as for publicly-accessible electric vehicle plugs. Among the issues that need to be resolved are how rates will be determined for EV (electric vehicle) charging and billing mechanisms. The study will be focused in Spain and the UK. As long as a good electric auto motor and electric vehicle motor controller can be procured, of which both can be procured at D&D Motor Systems, inc., anyone can build an EV car. (Electric car motors kits) MSD
A Tesla-Like All-Electric Sports Car
Today on CNBC, Chrysler CEO Bob Nardelli revealed a Tesla -like all-electric performance sports car called the Dodge ev along with three other vehicles operating either partially or entirely on an electric powertrain. The four vehicles are Chrysler's ENVI electric car motor program, and include an extended -electric Chrysler minivan, a new "gated community" electric called "the peapod" and a Jeep Wrangler four-door. The ev (electric vehicle), the first of the four unveiled, not only operates entirely on plug-in power like the Tesla Roadster and appears to have similar performance numbers, also has some striking visual similarities with the Tesla. And why shouldn't it? While the Tesla's built on the Lotus Elise, the Dodge ev appears to be based on the Lotus Europa. (electric motor conversion kits)
Which draws more juice from the electric grid, a big-screen plasma television or recharging an EV (electric vehicle)?
The answer is the car. But the electricity draw by plasma televisions is easing the minds of utility company executives across the nation as they plan for what is likely to be an electric car conversion of much of the country's vehicle fleet from gasoline to electricity in the coming years.
Rechargeable cars, industry officials say, consume about four times the electricity as plasma TVs.
But the industry already has dealt with increased electric demand from the millions of plasma TVs sold in recent years. Officials say that experience will help them deal with the vehicle fleet changeover to EV's. (electric motor conversion kits)
So as long as the changeover from internal combustion engines to electric vehicles is somewhat gradual, they should be able to handle it in the same way, Mark Duvall, program manager for electric transportation, power delivery and distribution for the Electric Power Research Institute, said Tuesday.
"We've already added to the grid the equivalent of several years' production of EV hybrids," Duvall said at a conference on EV's (electric vehicles) in San Jose. "The utilities, they stuck with it. They said, 'All right, that's what's happening. This is where the loads are going, and we're going to do this."'
Automakers, such as General Motors and Toyota , are planning to bring EV motors to the market as early as 2010. But speakers at the Plug-In 2008 conference say it will take much longer for them to arrive in mass numbers, due in part to a current lack of large-battery manufacturing capacity. (electric motor conversion kits) MSD
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Electric cars or EVs (electric vehicles) have been around for almost 170 years, but it's not just the limitations of battery power that have thwarted their more widespread use. Since Scottish businessman Robert Anderson pioneered the first electric carriage in the 1830s, most EV's have lacked one of the key markers of auto success: good looks. Just take a look at La Jamais Contente, designed by Belgian Camille Jenatzy in 1899, or Billard and Zarpe's space-age oddity, the Elektra King (1961). Even today's EV models — the REVA, or Zaps Zebra — are proof that the best adjective to describe most electric cars remains quirky.
Now two new models show that green can be given a devastatingly cool makeover. Britain's Lightning GT and the U.S.-built Tesla Roadster both reach 60 m.p.h. in 4 seconds or less, their makers claim, with top speeds approaching 130 m.p.h. The Lightning GT - unveiled at London's International Motor Show last week and set to be available from the end of 2009 - sports an impressive, sleek and sexy design, drawing on Aston Martin's classic British look. Tesla, which launched its hot, little open-top two-seater a couple of years ago, has already sold out of the 2008 model and is eagerly taking reservations for 2009. Battery power has rarely, if ever, looked this good.
Larry Horsley loves that he doesn't buy much gas, even though he drives his '95 Chevy S-10 back and forth to work each day. (Electric Car Conversion)
Horsley, a self-described do-it-yourselfer, simply plugs his EV motor(electric vehicle) truck into an electric wall outlet in his Douglasville, Georgia, garage and charges it overnight, instead of buying gasoline refined from mostly imported oil. Using electric motor conversion kits, many hobbyists are doing the same thing.
"If I can keep a dollar from going overseas, I'll spend two dollars," he said. The whole electric car motor conversion, including the truck and high performance EV motor, cost him about $12,000, which parts dealers say is about standard for an electric car conversion.
Another Atlanta-area tinkerer, David Kennington, converted his Honda Civic del Sol from gasoline to an EV for a different reason: "I'm a raging greenie," he said. (Electric Car Conversion)
Both Horsley and Kennington are fed up. They're among a growing number of Americans who are refusing to wait for big-car manufacturers to deliver a mainstream electric car, called EVs. Not only have they rebelled against the status quo by ripping out their gas-guzzling engines and replacing them with a zero-emission electric car motor, they say just about anyone can do an electric car conversion. As long as you get a good electric vehicle motor controller and electric auto motor, both can be purchased from D&D Motor Systems, Inc, you are well on your way. MSD
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