Electric vehicle battery

Further information: Rechargeable electricity storage system

The Tesla Roadster, the first 100 of which were scheduled for delivery in 2008, uses Li-Ion batteries to achieve 244 miles (393 km) per charge while also capable of going 0-60 in under 4 seconds.

An electric vehicle battery (EVB) or traction battery is a rechargeable battery used for propulsion of battery electric vehicles (BEVs). Traction batteries are used in forklifts, electric Golf carts, riding floor scrubbers, electric motorcycles, and other electric vehicles.

Electric vehicle batteries differ from starting, lighting, and ignition (SLI) batteries because they are designed to give power over sustained periods of time. Deep cycle batteries are used instead of SLI batteries for these applications. Traction batteries must be designed with a high ampere-hour capacity. Batteries for electric vehicles are characterized by their relatively high power-to-weight ratio, energy to weight ratio and energy density; smaller, lighter batteries reduce the weight of the vehicle and improve its performance. Compared to fossil fuels, all current battery technologies have much lower specific energy; and this often impacts the maximum all-electric range of the vehicles.

Batteries are usually the most expensive component of BEVs. The cost of battery manufacture is substantial, but increasing returns to scale lower costs. Since the late 1990s, advances in battery technologies have been driven by demand for laptop computers and mobile phones, with consumer demand for more features, larger, brighter displays, and longer battery time driving research and development in the field. The BEV marketplace has reaped the benefits of these advances.

Traction batteries are routinely used all day, and fast–charged all night.Forklifts, for instance, are usually discharged and recharged every 24 hours of the work week.

The predicted market for automobile traction batteries is over $37 billion in 2020.

On an energy basis, the price of electricity to run an EV is a small fraction of the cost of liquid fuel needed to produce an equivalent amount of energy (energy efficiency). The cost of replacing the batteries dominates the operating costs. Over the life of a battery, the cost of buying and recharging a battery is still usually lower than the cost of fossil fuels suitable for propelling a vehicle.

Types

Main article: Rechargeable battery

Old: Banks of conventional lead-acid car batteries are still commonly used for EV propulsion

75 watt-hour/kilogram lithium ion polymer battery prototypes. Newer Li-poly cells provide up to 130 Wh/kg and last through thousands of charging cycles.

Lead-acid

Traditionally, most EVs have used lead-acid batteries due to their mature technology, high availability, and low cost (exception: some early EVs, such as the Detroit Electric, used nickel-iron.) Like all batteries, these have an environmental impact through their construction, use, disposal or recycling. On the upside, vehicle battery recycling rates top 95% in the United States. Deep-cycle lead batteries are expensive and have a shorter life than the vehicle itself, typically needing replacement every 3 years.

Lead-acid batteries in EV applications end up being a significant (25%-50%) portion of the final vehicle mass. Like all batteries, they have significantly lower energy density than petroleum fuels—in this case, 30-40Wh/kg. While the difference isn't as extreme as it first appears due to the lighter drive-train in an EV, even the best batteries tend to lead to higher masses when applied to vehicles with a normal range. The efficiency (70-75%) and storage capacity of the current generation of common deep cycle lead acid batteries decreases with lower temperatures, and diverting power to run a heating coil reduces efficiency and range by up to 40%. Recent advances in battery efficiency, capacity, materials, safety, toxicity and durability are likely to allow these superior characteristics to be applied in car-sized EVs.

Charging and operation of batteries typically results in the emission of hydrogen, oxygen and sulfur, which are naturally occurring and normally harmless if properly vented. Early Citicar owners discovered that, if not vented properly, unpleasant sulfur smells would leak into the cabin immediately after charging.

Lead-acid batteries powered such early-modern EVs as the original versions of the EV1 and the RAV4EV.

Nickel metal hydride

Nickel-metal hydride batteries are now considered a relatively mature technology. While less efficient (60-70%) in charging and discharging than even lead-acid, they boast an energy density of 30-80Wh/kg, far higher than lead-acid. When used properly, nickel-metal hydride batteries can have exceptionally long lives, as has been demonstrated in their use in hybrid cars and surviving NiMH RAV4EVs that still operate well after 100,000 miles (160,000 km) and over a decade of service. Downsides include the poor efficiency, high self-discharge, very finicky charge cycles, and poor performance in cold weather. GM Ovonic produced the NiMH battery used in the second generation EV-1, and Cobasys makes a nearly identical battery (ten 1.2V 85Ah NiMH cells in series in contrast with eleven cells for Ovonic battery). This worked very well in the EV-1. Patent encumbrance has limited the use of these batteries in recent years.

Zebra

The sodium or "zebra" battery uses a molten chloroaluminate (NaAlCl4) sodium as the electrolyte. This chemistry is also occasionally referred to as "hot salt". A relatively mature technology, the Zebra battery boasts an energy density of 120Wh/kg and reasonable series resistance. Since the battery must be heated for use, cold weather doesn't strongly affect its operation except for in increasing heating costs. They have been used in several EVs. Zebras can last for a few thousand charge cycles and are nontoxic. The downsides to the Zebra battery include poor power density (<300 W/kg) and the requirement of having to heat the electrolyte to ~270*C, which wastes some energy and presents difficulties in long-term storage of charge.

Zebra batteries have been used in the Modec vehicle commercial vehicle since it entered production in 2006.

Lithium ion

Lithium-ion (and similar lithium polymer) batteries, widely known through their use in laptops and consumer electronics, dominate the most recent group of EVs in development. The traditional lithium-ion chemistry involves a lithium cobalt oxide cathode and a graphite anode. This yields cells with an impressive 200+Wh/kg energy density and good power density, and 80 to 90% charge/discharge efficiency. The downsides of traditional lithium-ion batteries include short cycle lives (hundreds to a few thousand charge cycles) and significant degradation with age. The cathode is also somewhat toxic. Also, traditional lithium-ion batteries can pose a fire safety risk if punctured or charged improperly. The maturity of this technology is moderate. The Tesla Roadster uses "blades" of traditional lithium-ion "laptop battery" cells that can be replaced individually as needed.

Most other EVs are utilizing new variations on lithium-ion chemistry that sacrifice energy density to provide extreme power density, fire resistance, environmental friendliness, very rapid charges (as low as a few minutes), and very long lifespans. These variants (phosphates, titanates, spinels, etc.) have been shown to have a much longer lifetime, with A123 expecting their lithium iron phosphate batteries to last for at least 10+ years and 7000+ charge cycles, and LG Chem expecting their lithium-manganese spinel batteries to last up to 40 years.

Much work is being done on lithium ion batteries in the lab. Lithium vanadium oxide has already made its way into the Subaru prototype G4e, doubling energy density. Silicon nanowires, silicon nanoparticles, and tin nanoparticles promise several times the energy density in the anode, while composite and superlattice cathodes also promise significant density improvements.

In 2009 Mitsubishi (i-MiEV) and Subaru (Stella) introduced electric vehicles offered for fleet then public sale.

Battery cost and parity

The cost of the battery when distributed over the life cycle of the vehicle (compared with an upto 10 years life cycle of a combustion vehicle) can easily be more than the cost of the electricity. This is because of the high initial cost relative to the life of the batteries. Battery weight is a problem; in trying to achieve a reasonable miles/charge the weight is still not reasonable for anything but local driving. For example a 1 kWhr battery using LiFePO4 technology costs $500USD. A typical small passenger electric car will use 8 kW-hrs for a 40 mile range each day. That is $4000USD for 40 x 250 x 4 , where annual cycles is 250 and life is 4 years. These are typical figures and as yet the life of LiFePo4 is not well established. Thus the cost/mile for just the batteries is 4000/40000 or $0.10USD /mile. However the cost of buying replacement packs could be easily double the manufacturers cost so giving $0.20USD/mile for the batteries. Add to this the cost of recycling and it is clear that with electricity cost at $0.10 to $0.20 per kW-hr the battery cost per mile is critical for future ecar development.

A solution to the range problem is detailed in an article on Battery Exchange and explains how the total battery needs would be reduced by using a battery exchange or battery swap system http://www.members.cox.net/rdoctors/evs.html. This requires substantial investment in setting up exchange stations but would allow for the use of lighter batteries as they would not be required to provide a many miles of use. Lighter batteries makes the ecar system far more efficient and lowers overall costs.

The LiFePO4 technology has a yielded batteries that have a higher miles/$ over the life of the packs but they require a complex control system to do this. The manufacture of the batteries is still being developed and is not a reliable source.

Some batteries can be leased or rented instead of bought (see Think Global).

One article indicates that 10 kW·h of battery energy provides a range of about 20 miles (32 km) in a Toyota Prius, but this is not a primary source, and does not fit with estimates elsewhere of about 5 miles (8.0 km) /(kW·h). The Chevrolet Volt is expected to achieve 50 MPG when running on the auxiliary power unit (a small onboard generator) - at 33% thermodynamic efficiency that would mean 12 kW·h for 50 miles (80 km), or about 240 watt hours per mile. For prices of 1 kW·h of charge with various different battery technologies, see the "Energy/Consumer Price" column in the "Table of rechargeable battery technologies" section in the rechargeable battery article.

Prototypes of 75 watt-hour/kilogram lithium ion polymer battery. Newer Li-ion cells can provide up to 130 Wh/kg and last through thousands of charging cycles.

Rechargeable batteries used in electric vehicles include lead-acid ("flooded", Deep cycle, and VRLA), NiCd, nickel metal hydride, lithium ion, Li-ion polymer, and, less commonly, zinc-air and molten salt batteries. The amount of electricity (i.e. electric charge) stored in batteries is measured in ampere hours or in coulombs, with the total energy often measured in watt hours.

EV Parity

Cost Parity

See also: Electric vehicle conversion

The parity means that an electric vehicle do not cost more in the showrooms than a similar combustion one. According to Kammen et al., 2008, new PEVs would become cost efficient to consumers if battery prices would decrease from 1300 $/kWh to about 500 $/kWh (so that the battery may pay for itself).

The Nissan Leaf is not going to cost more than its combustion rivals. The Leaf battery pack "costs £6,000 to produce" (US$9,060). That's about $375 per kWh, a very low number considering that many estimates for EV lithium-ion battery packs hover around $1,000/kWh.

Range Parity

Driving range parity means than the electric vehicle has the same range than a similar all-combustion vehicle (generally, 500 km).

Specifics

Internal Components

Battery pack designs for Electric Vehicles (EVs) are complex and vary widely by manufacturer and specific application. However, they all incorporate a combination of several simple mechanical and electrical component systems which perform the basic required functions of the pack.

The actual battery cells can have different chemistry, physical shapes, and sizes as preferred by various pack manufacturers. Battery pack will always incorporate many discrete cells connected in series and parallel to achieve the total voltage and current requirements of the pack. Battery packs for all electric drive EVs can contain several hundred individual cells.

To assist in manufacturing and assembly, the large stack of cells is typically grouped into smaller stacks called modules. Several of these modules will be placed into a single pack. Within each module the cells are welded together to complete the electrical path for current flow. Modules can also incorporate cooling mechanisms, temperature monitors, and other devices. In most cases, modules also allow for monitoring the voltage produced by each battery cell in the stack by the Battery Management System (BMS).

The battery cell stack has a main fuse which limits the current of the pack under a short circuit condition. A “service plug” or “service disconnect” can be removed to split the battery stack into two electrically isolated halves. With the service plug removed, the exposed main terminals of the battery present no high potential electrical danger to service technicians.

The battery pack also contains relays, or contactors, which control the distribution of the battery pack’s electrical power to the output terminals. In most cases there will be a minimum of two main relays which connect the battery cell stack to the main positive and negative output terminals of the pack, those supplying high current to the electrical drive motor. Some pack designs will include alternate current paths for pre-charging the drive system through a pre-charge resistor or for powering an auxiliary buss which will also have their own associated control relays. For obvious safety reasons these relays are all normally open.

The battery pack also contains a variety of temperature, voltage, and current sensors. Collection of data from the pack sensors and activation of the pack relays are accomplished by the pack ’s Battery Monitoring Unit (BMU) or Battery Management System (BMS). The BMS is also responsible for communications with the world outside the battery pack.

Charging

Batteries in BEVs must be periodically recharged. BEVs most commonly charge from the power grid (at home or using a street or shop recharging point), which is in turn generated from a variety of domestic resources, such as coal, hydroelectricity, nuclear and others. Home power such as roof top photovoltaic solar cell panels, microhydro or wind may also be used and are promoted because of concerns regarding global warming.

Charging time is limited primarily by the capacity of the grid connection. A normal household outlet is between 1.5 kilowatts (in the US, Canada, Japan, and other countries with 110 volt supply) to 3 kilowatts (in countries with 240 V supply). Many European countries feed domestic consumers with a 3 phase system fused at 16-25 amp allowing for a theoretical capacity around 20-30 kW. however, this capacity is also required to feed the rest of the location and can hence not be used practically and will also not be supported "en masse" by the distribution network. At this higher power level charging even a small, 7 kilowatt-hour (14–28 mi) pack, would probably require one hour. This is small compared to the effective power delivery rate of an average petrol pump, about 5,000 kilowatts. Even if the supply power can be increased, most batteries do not accept charge at greater than their charge rate ("1C"), because high charge rate has adverse effect on the discharge capacities of batteries.

In 1995, some charging stations charged BEVs in one hour. In November 1997, Ford purchased a fast-charge system produced by AeroVironment called "PosiCharge" for testing its fleets of Ranger EVs, which charged their lead-acid batteries in between six and fifteen minutes. In February 1998, General Motors announced a version of its "Magne Charge" system which could recharge NiMH batteries in about ten minutes, providing a range of sixty to one hundred miles.

In 2005, handheld device battery designs by Toshiba were claimed to be able to accept an 80% charge in as little as 60 seconds. Scaling this specific power characteristic up to the same 7 kilowatt-hour EV pack would result in the need for a peak of 340 kilowatts of power from some source for those 60 seconds. It is not clear that such batteries will work directly in BEVs as heat build-up may make them unsafe.

Most people do not always require fast recharging because they have enough time, six to eight hours, during the work day or overnight to recharge. As the charging does not require attention it takes a few seconds for an owner to plug in and unplug their vehicle. Many BEV drivers prefer refueling at home, avoiding the inconvenience of visiting a fuel station. Some workplaces provide special parking bays for electric vehicles with charging equipment provided.

Connectors

The charging power can be connected to the car in two ways. The first is a direct electrical connection known as conductive coupling. This might be as simple as a mains lead into a weatherproof socket through special high capacity cables with connectors to protect the user from high voltages.The modern standard for plug-in vehicle charging is the SAE 1772 conductive connector.

The second approach is known as inductive charging. A special 'paddle' is inserted into a slot on the car. The paddle is one winding of a transformer, while the other is built into the car. When the paddle is inserted it completes a magnetic circuit which provides power to the battery pack. In one inductive charging system [2], one winding is attached to the underside of the car, and the other stays on the floor of the garage. The advantage of the inductive approach is that there is no possibility of electrocution as there are no exposed conductors, although interlocks, special connectors and ground fault detectors can make conductive coupling nearly as safe. Inductive charging can also reduce vehicle weight, by moving more charging componentry offboard. An inductive charging proponent from Toyota contended in 1998 that overall cost differences were minimal, while a conductive charging proponent from Ford contended that conductive charging was more cost efficient.

Recharging spots

Main article: Charging station

In France, Électricité de France (EDF) and Toyota are installing recharging points for PHEVs on roads, streets and parking lots.. EDF is also partnering with Elektromotive, Ltd. to install 250 new charging points over six months from October 2007 in London and elsewhere in the UK. Recharging points also can be installed for specific uses, as in taxi stands. Public charging has been described as costly, unmanageable, and resource-intensive.

Travel range before recharging and trailers

The General Motors EV1 had a range of 75 to 150 miles (240 km) with NiMH batteries in 1999.

The range of a BEV depends on the number and type of batteries used, terrain, weather, and the performance of the driver. The weight and type of vehicle also have an impact just as they do on the mileage of traditional vehicles. Electric vehicle conversion performance depends on a number of factors including the battery chemistry:

• Lead-acid batteries are the most available and inexpensive. Such conversions generally have a range of 30 to 80 km (20 to 50 mi). Production EVs with lead-acid batteries are capable of up to 130 km (80 mi) per charge.

• NiMH batteries have higher energy density and may deliver up to 200 km (120 mi) of range.

• New lithium-ion battery-equipped EVs provide 320–480 km (200–300 mi) of range per charge. Lithium is also less expensive than nickel.

• Nickel-zinc battery are cheaper and lighter than Nickel-cadmium batteries. They are also cheaper (but not as light) as Lithium-Ion batteries. [3]

Finding the economic balance of range versus performance, battery capacity versus weight, and battery type versus cost challenges every EV manufacturer.

With an AC system or Advanced DC systems regenerative braking can extend range by up to 50% under extreme traffic conditions without complete stopping. Otherwise, the range is extended by about 10 to 15% in city driving, and only negligibly in highway driving, depending upon terrain.

BEVs (including buses and trucks) can also use genset trailers and pusher trailers in order to extend their range when desired without the additional weight during normal short range use. Discharged baset trailers can be replaced by recharged ones in a route point. If rented then maintenance costs can be deferred to the agency.

Such BEVs can become Hybrid vehicles depending on the trailer and car types of energy and powertrain.

Swapping And Removing

Main article: Exchange station

An alternative to recharging is to exchange drained or nearly drained batteries (or battery range extender modules) with fully charged batteries. This is called battery swapping and is done in exchange stations .

On the other hand, MIRA has announced a retrofit hybrid conversion kit that provides removable battery packs that plug into a wall outlet for charging . Also XP Vehicles uses extension-cord-free charging hot-swap battery ( removable power pack to recharge at home without extension cord ).

Advantages of swap stations

1. The consumer is no longer concerned with battery capital cost, quality, technology, maintenance, or warrantee issues;
2. Swapping is far faster and more convenient than charging (or even getting gasoline or diesel fuel);
3. For those who do not have garages in which to charge overnight, it is a necessity;
4. Swap stations would allow for grid storage;
5. Standardization of batteries allows for competition among battery makers, driving down EV costs;
6. Swapping does away with the need for costly, unmanageable, and resource-intensive public charging.

Re-filling

Zinc-bromine flow batteries can be re-filled using a liquid, instead of recharged by connectors, saving time.

Leasing

Three companies are working on battery lease plans. Greenstop has completed trials of their ENVI Grid Network which allows consumers to easily monitor and recharge electric vehicle batteries. Think Car USA plans to lease the batteries for its City electric car to go on sale next year. Better Place is creating a system for consumers to "subscribe" to a service that offers recharging stations and battery exchange.

Electric utilities are considering plans which would include providing electric vehicles to users (at a low price) and get their profits from selling the energy .

V2G and afteruse

Main article: Vehicle-to-grid

Smart grid allows BEVs to provide power to the grid at any time, especially:

• During peak load periods, when the selling price of electricity can be very high. These vehicles can then be recharged during off-peak hours at cheaper rates while helping to absorb excess night time generation. Here the vehicles serve as a distributed battery storage system to buffer power.

• During blackouts, as backup.

Pacific Gas and Electric Company (PG&E) has suggested that utilities could purchase used batteries for backup and load levelling purposes. They state that while these used batteries may be no longer usable in vehicles, their residual capacity still has significant value.

Lifespan

Individual batteries are usually arranged into large battery packs of various voltage and ampere-hour capacity products to give the required energy capacity. Battery service life should be considered when calculating the extended cost of ownership, as all batteries eventually wear out and must be replaced. The rate at which they expire depends on a number of factors.

The depth of discharge (DOD) is the recommended proportion of the total available energy storage for which that battery will achieve its rated cycles. Deep cycle lead-acid batteries generally should not be discharged to below 20% of total capacity. More modern formulations can survive deeper cycles.

In real world use, some fleet Toyota RAV4 EVs, using NiMH batteries, have exceeded 100,000 miles (160,000 km) with little degradation in their daily range. Quoting that report's concluding assessment:

"The five-vehicle test is demonstrating the long-term durability of Nickel Metal Hydride batteries and electric drive trains. Only slight performance degradation has been observed to-date on four out of five vehicles.... EVTC test data provide strong evidence that all five vehicles will exceed the 100,000-mile (160,000 km) mark. SCE’s positive experience points to the very strong likelihood of a 130,000 to 150,000-mile (240,000 km) Nickel Metal Hydride battery and drive-train operational life. EVs can therefore match or exceed the lifecycle miles of comparable internal combustion engine vehicles.

"In June 2003 the 320 RAV4 EVs of the SCE fleet were used primarily by meter readers, service managers, field representatives, service planners and mail handlers, and for security patrols and carpools. In five years of operation, the RAV4 EV fleet had logged more than 6.9 million miles, eliminating about 830 tons of air pollutants, and preventing more than 3,700 tons of tailpipe carbon dioxide emissions. Given the successful operation of its EVs to-date, SCE plans to continue using them well after they all log 100,000-miles."

Lithium ion batteries are perishable to some degree; they lose some of their maximum storage capacity per year even if they are not used. Nickel metal hydride batteries lose much less capacity, but are cheaper for the storage capacity they give, but have a lower total capacity initially for the same weight.

Jay Leno's 1909 Baker Electric (see Baker Motor Vehicle) still operates on its original Edison cells. Battery replacement costs of BEVs may be partially or fully offset by the lack of regular maintenance such as oil and filter changes required for ICEVs, and by the greater reliability of BEVs due to their fewer moving parts. They also do away with many other parts that normally require servicing and maintenance in a regular car, such as on the gearbox, cooling system, and engine tuning. And by the time batteries do finally need definitive replacement, they can be replaced with later generation ones which may offer better performance characteristics, in the same way as you might replace old batteries from a digital camera with improved ones.

Safety

The safety issues of battery electric vehicles are largely dealt with by the international standard ISO 6469. This document is divided in three parts dealing with specific issues:

• On-board electrical energy storage, i.e. the battery
• Functional safety means and protection against failures
• Protection of persons against electrical hazards.

Firefighters and rescue personnel receive special training to deal with the higher voltages and chemicals encountered in electric and hybrid electric vehicle accidents. While BEV accidents may present unusual problems, such as fires and fumes resulting from rapid battery discharge, there is apparently no available information regarding whether they are inherently more or less dangerous than gasoline or diesel internal combustion vehicles which carry flammable fuels.

Patents

See also: Open hardware

Patents relevant to the use of Nickel metal hydride cells in cars are held by an offshoot of Chevron, an oil company. Conspiracy theorists maintain that these patents are being used to suppress development of this out-dated technology.

Research, development and innovation

R&D Magazine's prestigious R&D 100 Awards — also called the “Oscars of Invention”— for 2008:

• Argonne National Laboratory has received an award for EnerDel/Argonne High-Power Lithium-Ion Battery for Hybrid Electric Vehicles – a highly reliable and extremely safe device that is lighter in weight, more compact, more powerful and longer lasting than the nickel-metal hydride (Ni-MH) batteries that are found in today’s hybrid electric vehicles .
• Lawrence Berkeley National Laboratory : Nanostructured Polymer Electrolyte for Rechargeable Lithium Batteries – a polymer electrolyte that enables the development of rechargeable lithium metal batteries with an energy density that is high enough "to enable electric battery-driven transportation technology" .

Carbon nanotube battery

See also: Carbon nanotube

Next-Alternative Carbon Nano Tube battery pack will deliver 380 miles (610 km) range and can be recharged in less than 10 minutes. The nowadays battery short life (three to four years, perhaps 200 full charge/discharge cycles) is extended by at minimum of 4 times with this technology.

Future

The future of battery electric vehicles depends primarily upon the cost and availability of batteries with high energy densities, power density, and long life, as all other aspects such as motors, motor controllers, and chargers are fairly mature and cost-competitive with internal combustion engine components. Li-ion, Li-poly and zinc-air batteries have demonstrated energy densities high enough to deliver range and recharge times comparable to conventional vehicles.

Bolloré a French automotive parts group developed a concept car the "Bluecar" using Lithium metal polymer batteries developed by a subsidiary Batscap. It had a range of 250 km and top speed of 125 km/h.

Firefly Energy who is now bankrupt has developed a carbon foam-based lead acid battery with a reported capacity from 90-160 Watt-hours/kg

The cathodes of early 2007 lithium-ion batteries are made from lithium-cobalt metal oxide. This material is expensive, and can release oxygen if its cell is overcharged. If the cobalt is replaced with iron phosphates, the cells will not burn or release oxygen under any charge. The price premium for early 2007 hybrids is about US $5000, some $3000 of which is for their NiMH battery packs. At early 2007 gasoline and electricity prices, that would break even after six to ten years of operation. The hybrid premium could fall to $2000 in five years, with $1200 or more of that being cost of lithium-ion batteries, providing a three-year payback.

Ultracapacitors

Electric double-layer capacitors (or "ultracapacitors") are used in some electric vehicles, such as AFS Trinity's concept prototype, to store rapidly available energy with their high power density, in order to keep batteries within safe resistive heating limits and extend battery life . The Ultrabattery combines a supercapacitor and a battery in a single unit, creating an electric vehicle battery that lasts longer, costs less and is more powerful than current technologies used in plug-in hybrid electric vehicles (PHEVs).

Since commercially available ultracapacitors have a low energy density no production electric cars use ultracapacitors exclusively.

Promotion

US President Barack Obama has announced 48 new advanced battery and electric drive projects that will receive $2.4 billion in funding under the American Recovery and Reinvestment Act. These projects will accelerate the development of U.S. manufacturing capacity for batteries and electric drive components as well as the deployment of electric drive vehicles, helping to establish American leadership in creating the next generation of advanced vehicles.

The announcement marks the single largest investment in advanced battery technology for hybrid and electric-drive vehicles ever made. Industry officials expect that this $2.4 billion investment, coupled with another $2.4 billion in cost share from the award winners, will result directly in the creation tens of thousands of manufacturing jobs in the U.S. battery and auto industries.

The new awards cover $1.5 billion in grants to United States-based manufacturers to produce batteries and their components and to expand battery recycling capacity.

Vice President Biden announced in Detroit over $1 billion in grants to companies and universities based in Michigan. Reflecting the state's leadership in clean energy manufacturing, Michigan companies and institutions are receiving the largest share of grant funding of any state. Two companies, A123 and Johnson Controls, will receive a total of approximately $550 million to establish a manufacturing base in the state for advanced batteries, and two others, Compact Power and Dow Kokam, will receive a total of over $300 million for manufacturing battery cells and materials. Large automakers based in Michigan, including GM, Chrysler, and Ford, will receive a total of more than $400 million to manufacture batteries and electric drive components. And three educational institutions in Michigan — the University of Michigan, Wayne State University in Detroit, and Michigan Technological University in Houghton, in the Upper Peninsula — will receive a total of more than $10 million for education and workforce training programs to train researchers, technicians, and service providers, and to conduct consumer research to accelerate the transition towards advanced vehicles and batteries.

Energy Secretary Steven Chu visited Celgard, in Charlotte, North Carolina, to announce a $49 million grant for the company to expand its separator production capacity to serve the expected increased demand for lithium-ion batteries from manufacturing facilities in the United States. Celgard will be expanding its manufacturing capacity in Charlotte, North Carolina, and nearby Aiken, South Carolina, and the company expects the new separator production to come online in 2010. Celgard expects that approximately hundreds of jobs could be created, with the first of those jobs beginning as early as fall 2009.

EPA Administrator Lisa Jackson was in St. Petersburg, Florida, to announce a $95.5 million grant for Saft America, Inc. to construct a new plant in Jacksonville on the site of the former Cecil Field military base, to manufacture lithium-ion cells, modules and battery packs for military, industrial, and agricultural vehicles.

Deputy Secretary of the Department of Transportation John Porcari visited East Penn Manufacturing Co., in Lyon Station, Pennsylvania, to award the company a $32.5 million grant to increase production capacity for their valve regulated lead-acid batteries and the UltraBattery, a lead-acid battery combined with a carbon supercapacitor, for micro and mild hybrid applications.

Lead-acid battery

Flooded lead-acid batteries are the cheapest and most common traction batteries available, usually discharged to roughly 80%. They will accept high charge rates for fast charges. Flooded batteries require inspection of electrolyte level and replacement of water.

Absorbed Glass Mat valve regulated (AGM) deep cycle lead acid batteries are more expensive as it takes more to build them, but with reduced internal resistance and more pure lead contents, they charge more quickly and house more power in a smaller package than their flooded brothers. However, they are only to be discharged to 50% to maximize life cycles¹. AGM offers power, without the mess, outstanding charge times, and are OSHA approved for public spaces. AGM Batteries will not crack or freeze but they do go dormant at -40 F.¹

See also

• List of electric vehicle battery manufacturers
• Better Place
• Deep cycle battery
• Exchange station
• Flywheel energy storage
• Patent encumbrance of large automotive NiMH batteries
• Power-to-weight ratio
• Traction battery
• Traction motor
• Vehicle-to-grid (V2G)

External links

• How Electric Car Batteries Work at HowStuffWorks
• Alternative Fueling Station Locator, charging stations (EERE).
• McCain Calls for US$300 Million Prize for Car Battery.
• Under the lead of an organization affiliated with the Ministry of Economy, Trade and Industry, Japan to work out next-gen car battery norms.
• Testing EV Battery Packs in a Manufacturing Environment
• Car Traction Batteries - the New Gold Rush 2010-2020 (IDTechEx).
• AGM Deep Cycle Battery Graphs
• Lead Acid Batteries and the Environment
• Traction Batteries Construction
• Glossary of Battery Terms and Definitions