Range extender

The key function of the range extender is to increase the vehicle's range. Range autonomy is one of the main barriers for the commercial success of electric vehicles, and extending the vehicle's range when the battery is depleted helps alleviate range anxiety.{{cite web|last1=Vortisch|first1=Peter|last2=Chlond|first2=Bastian|last3=Weiß|first3=Christine|last4=Mallig|first4=Nicolai|date=June 2015|title=Electric Vehicles with Range Extender as a Suitable Technology (EVREST)|url=http://www.ifv.kit.edu/english/26_EVREST.php|access-date=2015-05-18|publisher=Karlsruher Institut für Technologie}}

A range extender can also reduce the consumption of the range-extending fuel (such as gasoline) by using the primary fuel (such as battery power), while still maintaining the driving range of a single-fuel vehicle powered by a fuel such as gasoline. The range-extending fuel is generally considered to be less environmentally and economically friendly to use than the primary fuel source, so the vehicle control system gives preference to using the primary fuel if it's available. However, due to range limitations with the primary fuel source, the range extender allows the vehicle to get many of the cost and environmental benefits of the primary fuel, while maintaining the full driving range of the range extending fuel source.{{cite web|last1=Bradley|first1=Thomas|last2=Frank|first2=Andrew|title=Design, demonstrations and sustainability impact assessments for plug-in hybrid electric vehicles|url=http://www.engr.colostate.edu/~thb/Publications/Design%20Development%20and%20Sustainability%20impacts%20assessments%20for%20PHEVs_FINAL.pdf}} That said, the benefits (cost, carbon emissions) derived from using a vehicle with a range extender ultimately depend on how the vehicle is driven, and in particular how often the range extender is used.{{cite web|last1=Bradley|first1=Thomas|last2=Quinn|first2=Casey|title=Analysis of plug-in hybrid electric vehicle utility factors|url=http://www.engr.colostate.edu/~thb/Publications/Bradley%20and%20Quinn%20Analysis%20of%20Plug%20in%20Hybrid%20Electric%20Vehicle%20Utility%20Factors.pdf}}

As an example, cars such as the BMW i3 with optional range extender and the Chevrolet Volt are equipped with sufficiently large batteries to drive {{convert|50-100|mile|km|round=5|order=flip|abbr=in}}, which is enough for many trips but not sufficient to drive long distances. As such, the driver may use battery power for commuting and daily driving, but still be able to drive from New York to Boston (about {{convert|200|miles|km|round=5|order=flip|abbr=in|disp=comma}}) by using the auxiliary gasoline internal combustion engine, without stopping frequently to charge the battery (which can take hours). The vehicle owner therefore accrues the benefits of using cheaper and less carbon-intensive electric power for most driving, while maintaining the ability to embark on longer trips with the same vehicle.

When a range extender uses conventional fuels they can re-fuel at regular fuel stations, which provides them with a similar driving range to conventional automobiles.{{cite web|author=Michael Graham Richard|date=2009-10-14|title=Could Range Anxiety Sabotage the Promise of Electric Cars?|url=http://auto.howstuffworks.com/range-anxiety-electric-cars1.htm|url-status=dead|archive-url=https://web.archive.org/web/20131203012724/http://auto.howstuffworks.com/range-anxiety-electric-cars1.htm|archive-date=2013-12-03|access-date=2010-03-14|publisher=Discovery's Planet Green}}{{cite web|title=Plug-In Hybrid Electric Vehicle (PHEV)|url=http://www.ceage.vt.edu/phev|url-status=dead|archive-url=https://web.archive.org/web/20110720110541/http://www.ceage.vt.edu/phev|archive-date=2011-07-20|access-date=2010-12-29|publisher=Center for Energy and the Global Environment, Virginia Tech}}{{cite web|title=What Is A Plug-in Hybrid Car?|url=http://www.hybridcars.com/plug-in-hybrid-cars|access-date=2010-12-29|publisher=HybridCars.com}}

As a range-extended electric vehicle is only propelled by the electric motor it can do away with the weight and cost associated with the gearbox transmission system typically used in internal combustion engine cars. Further, as the range extender does not need to increase or decrease output in line with the power needs of the vehicle (this task is handled by the electric motor) the range extender can be sized to satisfy the vehicle's average power requirement rather than its peak power requirement (such as when accelerating). The range extender can also operate much closer to its most efficient rotational speed. These design features allow range-extended electric vehicles to convert fossil fuel energy to electric power and vehicle motion relatively efficiently. The combustion engine may also have a longer lifespan, as it does not need to run at high rpm (which causes increased wear and tear).

• The first generation range extenders are off the shelf internal combustion engines.
• The second generation consists of piston engines with new designs from scratch for fairly constant load in series hybrids. They include the wankel engines, rotary combustion engines and free piston engines.
• The third generation are micro turbines and fuel cells that work at constant load.{{Cite book |url=http://www.idtechex.com/en/research-report/range-extenders-for-electric-vehicles-land-water-and-air-2013-2023/357 |title=Range Extenders for Electric Vehicles Land, Water & Air 2013-2023 |date=2013-07-08 |via=www.idtechex.com}}

According to 2012 Amendments to the Zero Emission Vehicle Regulations adopted in March 2012 by the California Air Resources Board (CARB), a range-extended battery-electric vehicle, designated as BEVx, should comply, among others, with the following criteria:

• The vehicle must have a rated all-electric range of at least {{Convert|75|mi|abbr=in|order=flip|round=5}}. This is higher than the {{Convert|50|mi|abbr=in|order=flip|0}} required of a zero-emission vehicle;
• The auxiliary power unit (APU) must provide range less than or equal to battery range;
• The APU must not be capable of switching on until the battery charge has been depleted;
• The vehicle must meet super ultra low emission vehicle (SULEV) requirements; and
• The APU and all associated fuel systems must comply with zero evaporative emissions requirements.

Range extenders are commonly used in marine (autonomous underwater vehicle), aircraft and Generator/Utility, automotive{{Cite web|url=http://www.klimafonds.gv.at/assets/Uploads/2AVL-Beste.pdf|title=Electric vehicle and range extender}} and hybrid electric vehicle applications.{{Cite web|url=http://www.dukeengines.com/application/range-ext/|title=Multiple Use Engine Including marine, military, automobile, light aircraft|website=www.dukeengines.com}}

File:DCA 06 2012 Chevy Volt 4035.JPG is a series plug-in hybrid referred by General Motors as "an electric car with extended range."]]

General Motors describes the Chevrolet Volt as an electric vehicle equipped with a 16 kWh battery plus a "range extending" gasoline powered internal combustion engine (ICE) as a genset and therefore dubbed the Volt an "Extended Range Electric Vehicle" or E-REV.{{cite web| url =http://wheels.blogs.nytimes.com/2009/06/25/chevrolet-volt-hits-road-ahead-of-schedule/| title = Chevrolet Volt Hits Road, Ahead of Schedule| work = The New York Times|date=2009-06-25| access-date = 2014-01-19}}{{cite web | url =http://www.mlive.com/auto/index.ssf/2010/10/is_the_chevrolet_volt_a_true_e.html | title = Is the Chevrolet Volt a true electric car? General Motors defends EV label| publisher = MLive.com| author = Jonathan Oosting| date = 2010-10-12|access-date = 2010-06-02}} In a January 2011 interview, the Chevy Volt's Global Chief Engineer, Pamela Fletcher, referred to the Volt as "an electric car with extended range."{{Cite news| last = Kuchment | first = Anna| date = January 2011 | access-date = 2011-03-27| title = Practically Green: A Q&A with the Chevy Volt's Chief Engineer| periodical = Scientific American| publisher = Nature America| volume = 304 | issue = 1| page = 25| url =http://www.scientificamerican.com/article.cfm?id=practically-green| issn = 0036-8733}} The Volt operates as a purely electric car for the first {{convert|25-50|mi|km|abbr=in|0|order=flip}} in charge-depleting mode. When the battery capacity drops below a pre-established threshold from full charge, the vehicle enters charge-sustaining mode, and the Volt's control system will select the most optimally efficient drive mode to improve performance and boost high-speed efficiency.{{cite news|url=https://www.nytimes.com/2010/10/17/automobiles/17VOLT.html?_r=1&scp=1&sq=Chevy%20Volt&st=cse|title=Sorting Myth From Fact as Volt Makes Its Debut|work=New York Times|author=Norman Mayersohn|date=2010-10-15|access-date=2010-10-17}}{{cite news

| url = http://www.motortrend.com/features/editorial/1010_unbolting_the_chevy_volt_to_see_how_it_ticks/index.html| title = Unbolting the Chevy Volt to See How it Ticks| work = Motor Trend|author=Frank Markus| date = 2010-10-10| access-date = 2010-10-11}}

According to General Motors' real time tally of the distance driven by Volt owners in North America, by mid-June 2014 they had accumulated more than {{convert|500|mi|km|sigfig=2|abbr=in|order=flip|disp=preunit|million |million all-electric }}. GM also reported that Volt owners driving is more than 63% in all-electric mode. Volt owners who charge regularly typically drive more than {{convert|970|mi|km|abbr=in|order=flip|-1}} between fill-ups and visit the gasoline station less than once a month.{{cite press release |url=http://media.gm.com/media/us/en/gm/news.detail.html/content/Pages/news/us/en/2014/Jun/0617-volt.html |title=Chevrolet Volt Owners Surpass Half a Billion Electric Miles |publisher=General Motors |location=US |date=2014-06-17 |access-date=2014-07-02}} A similar report, issued by GM in August 2016, reported that Volt owners have accumulated almost {{convert|1.5|mi|km|abbr=in|order=flip|1|disp=preunit| billion | billion }} driven in EV mode, representing 60% of their total distance traveled.{{cite news | url=http://www.hybridcars.com/100000th-chevy-volt-sold-in-us/ | title= 100,000th Chevy Volt Sold in US |first=Jeff |last=Cobb |work=HybridCars.com | date=2016-08-01 |access-date= 2016-08-09}}

File:BMW i3 (19939421151).jpg, which allows the car to qualify as a range-extended battery-electric vehicle (BEVx) according to the California Air Resources Board regulations.]]

The BMW i3 all-electric car with at least 22 kWh battery capacity offers an optional gasoline-powered range extender APU.{{cite web|url=http://www.motorauthority.com/blog/1047387_first-major-outing-for-bmw-megacity-vehicle-at-2012-london-olympic-games|title=First Major Outing For BMW Megacity Vehicle At 2012 London Olympic Games|author= Viknesh Vijayenthiran|publisher=Motor Authority|date=2010-07-20|access-date=2010-07-23}} The range extender is the same 647 cc two-cylinder gasoline engine used in the BMW C650 GT scooter with a {{convert|9|L|abbr=on}} fuel tank. The US model originally had its tank electronically limited to a smaller 7 L capacity.{{cite news|url=https://thegreencarguy.com/bmw-i3-ev-gets-range-boost-2017/|title=BMW i3 Range Boost: Up 40% for 2017| author=John O'Dell| website=The Green Car Guy| access-date=2020-09-18}} The range extender engages when the battery level drops to 6%. It generates electricity to extend the range from {{Convert|80|-|100|mi|abbr=in|disp=flip}} to {{Convert|240|-|300|km|abbr=in}}{{cite web|url=http://insideevs.com/bmw-i3-range-extender-to-offer-up-to-87-more-miles-decreases-performance/|title=BMW i3 Range Extender To Offer Up to 87 More Miles, Decreases Performance|author=Jay Cole|website= InsideEVs |date=2013-07-29|access-date=2013-07-29}}{{cite news|url=http://www.autocar.co.uk/car-news/new-cars/first-rides-bmw-i8-hybrid-sportscar-and-all-electric-i3|title=First rides in BMW i8 hybrid sportscar and all-electric i3|author= Greg Kable|work=Autocar|date=2013-02-24|access-date=2013-02-27}} Performance in range-extending mode may be more limited than when it is running on battery power, as BMW designed the range extender as a backup to enable reaching a recharging location.{{cite web|url=http://www.greencarreports.com/news/1082814_bmw-i3-electric-car-rex-range-extender-not-for-daily-use/page-2 |title=BMW i3 Electric Car: ReX Range Extender Not For Daily Use? |author=John Voelcker|publisher=Green Car Reports|date=2013-03-12|access-date=2013-03-12}}

According to BMW, at the beginning of the i3 release, the use of range-extender was much more than the carmaker expected, more than 60%. Over time it has decreased significantly, with some people almost never using it, and by 2016 it is being regularly used in fewer than 5% of i3s.{{cite news|last=Duff | first=Mike | work =Car and Driver| url=http://blog.caranddriver.com/bmw-i-chief-i5-ev-model-coming-will-offer-optional-range-extender |title= BMW i Chief: Larger i Models Will Offer Optional Range-Extender| date=2016-03-08 |access-date=2016-03-18}}

The range-extender option costs an additional {{USD|3,850}} in the United States,{{cite news|url=http://wheels.blogs.nytimes.com/2013/07/29/bmw-unveils-i3-electric-car/?ref=automobiles&_r=1&|title=BMW Unveils i3 Electric Car|author=Benjamin Preston|work=The New York Times|date=2013-07-29|access-date=2013-07-29}} an additional {{euro|4,710}} (~ {{USD|6300}}) in France,{{cite web|url=http://www.avem.fr/actualite-voiture-electrique-la-bmw-i3-officiellement-revelee-4303.html|title=Voiture électrique – La BMW i3 officiellement révélée|language=fr|trans-title=Electric car – the BMW i3 officially revealed|author=Michaël Torregrossa|publisher= Association pour l'Avenir du Véhicule Electrique Méditerranéen (AVEM)|date=2013-07-30|access-date=2013-07-31}} and {{euro|4,490}} (~ {{USD|6000}}) in the Netherlands.{{cite web|url=http://insideevs.com/official-bmw-i3-range-extender-option-adds-4490-euros-5919-us-to-price-tag-in-netherlands/|title=Official: BMW i3 Range Extender Option Adds 4,490 Euros ($5,919 US) to Price Tag in Netherlands|author=Eric Loveday|publisher=InsideEVs.com|date=2013-07-22|access-date=2013-07-29}}

The range-extender option of the BMW i3 was designed to meet the CARB regulation for an auxiliary power unit (APU) called REx. According to rules CARB adopted in March 2012, the 2014 BMW i3 with a REx unit fitted will be the first car to qualify as a range-extended battery-electric vehicle or "BEVx." CARB describes this type of electric vehicle as "a relatively high-electric range battery-electric vehicle (BEV) to which an APU is added." The APU, which maintains battery charge at about 6% after the pack has been depleted in normal use, is strictly limited in the additional range it can provide.{{cite web|url=http://www.greencarreports.com/news/1087888_2014-bmw-i3-electric-car-why-california-set-range-requirements-engine-limits|title=2014 BMW i3 Electric Car: Why California Set Range Requirements, Engine Limits|author=John Voelcker|publisher=Green Car Reports|date=2013-10-23|access-date=2014-01-19}}{{cite web|url=http://www.bmwblog.com/2014/10/24/i3-rex-one-owners-thoughts-bevx-restrictions/|title=The i3 REx: One Owners Thoughts on the BEVx Restrictions|author=Tom Moloughney|publisher=BMWBlog|date=2014-10-24|access-date=2014-01-24}}

File:Fisker at speed in the fog trimmed.jpg is an extended-range electric vehicle.]]

Other range-extended electric vehicles include the discontinued Cadillac ELR and the discontinued Fisker Karma.{{cite web|url = http://www.plugincars.com/frost-sullivan-predicts-boom-sales-extended-range-electric-vehicles-2018-126357.html|title = Frost & Sullivan Predicts Boom in Extended-Range Electric Vehicles|author = Eric Loveday|publisher = PluginCars.com|date = 2013-02-06|access-date = 2013-08-11}}{{cite web|url=http://green.autoblog.com/2009/04/02/greenlings-what-is-a-series-hybrid-extended-range-electric-vehi/|title=What is a series hybrid/extended range electric vehicle?|author= Sam Abuelsamid |publisher=Autoblog Green|date=2009-04-02|access-date=2013-08-11}}{{cite web|url=http://www.greencarreports.com/overview/fisker_karma_2012|title=2012 Fisker Karma -Review|author=John Voelcker|publisher=Green Car Reports|date=2012-03-13|access-date=2013-08-11}} In June 2016, Nissan announced it will introduce a compact range extender car in Japan before March 2017.{{needs update|date=July 2024}} The series plug-in hybrid will use a new hybrid system, dubbed e-Power, which debuted with the Nissan Gripz concept crossover showcased at the 2015 Frankfurt Auto Show.{{cite news | url=http://www.autonews.com/article/20160625/OEM05/306279981/nissans-to-do-list-range-autonomy | title=Nissan's to-do list: Range, autonomy | first=Hans | last=Greimel | work=Automotive News | date=2016-06-25 | access-date=2016-06-27}} The technology, without the plug-in ability, had been deployed to the Nissan Note e-Power and Nissan Kicks e-Power.

The LEVC TX London taxi was launched in 2017 and features a 33 kWh battery that is charged by a 1.5-litre gasoline engine.{{cite web |title=LEVC TX review: London's new electric taxi driven |url=https://www.carmagazine.co.uk/car-reviews/levc/levc-tx-review-londons-new-electric-black-taxi-cab-driven/ |first=Curtis |last=Moldrich |work=Car Magazine |location=UK |access-date=2018-10-17 |date=2018-04-04}}

The Li Auto One is a large SUV which combines a 41-kWh battery with a small 1.2-litre gasoline engine.{{Cite news |url=https://www.carscoops.com/2019/03/li-xiangs-first-model-has-six-seats-four-screens-and-a-hybrid-powertrain/ |title=Li Xiang Launches With "One" SUV With Six Seats, Four Screens, Hybrid Powertrain |date=2019-03-21 |website=Carscoops}}{{Cite web|url=https://www.lixiang.com/mall/one.html|title=理想汽车 | 创造移动的家, 创造幸福的家 |trans-title=Ideal car | create a mobile home, create a happy home |website=lixiang |location=China |language=Chinese |access-date=2021-10-06}}

This approach has also been used for heavy vehicles, such as Wrightbus's Gemini 2{{Cite news |title=A hybrid bus that cuts fuel consumption in half |url=http://www.autoblog.com/2009/05/14/a-hybrid-bus-that-cuts-fuel-consumption-in-half/ |work=Autoblog |date=2009-05-14 |access-date=2015-11-21 |first=Xavier |last=Navarro}} and New Routemaster{{Cite web |url=http://www.wrightsgroup.com/datasheets/Routemaster%20spec%20sheet.pdf |title=New Routemaster technical specifications |access-date=2015-11-21 |website=Wrights Group }} buses.

Hydrogen fuel cells have also been used as a range extender for battery electric buses, allowing them to have greater range.{{Cite web |date=2019-09-05 |title=Hamburg to test the eCitaro with fuel cell range extender in 2021 |url=https://www.sustainable-bus.com/fuel-cell-bus/hamburg-to-test-the-ecitaro-with-fuel-cell-range-extender-in-2021/ |access-date=2022-10-27 |website=Sustainable Bus |language=en-US}} For example, the Mercedes-Benz eCitaro has a range of {{convert|280|km|-1}} as a battery electric model, with the eCitaro fuel cell bus having a range of {{convert|400|km|-1}} thanks to a 60kW Toyota fuel cell that recharges the battery.{{Cite web |date=23 May 2023 |title=Drum roll for Mercedes eCitaro with FC range extender |url=https://www.electrive.com/2023/05/23/drum-roll-for-mercedes-ecitaro-with-fc-range-extender/ |access-date=2023-08-10 |website=electrive.com |language=en-US}}

Ford has patents for a bed mounted gasoline-powered generator for their fully electric pickups.{{Cite web|title=Ford F-150 Electric Patent Shows Range-Extending Gas Generator|url=https://www.motor1.com/news/446705/ford-f150-electric-patent-images/|access-date=2021-10-24|website=Motor1.com|language=en}} Rivian has patents for bed mounted additional batteries for increased range.{{Cite web|last=Stumpf|first=Rob|title=Rivian Patents Removable Bed-Mounted Battery Pack for Extended Range|url=https://www.thedrive.com/news/37583/new-rivian-patent-confirms-removable-bed-mounted-battery-pack-for-extended-range|access-date=2021-10-24|website=The Drive|date=11 November 2020 |language=en}} Rivian electric trucks can charge each other for extended range.{{Cite web|title=Rivian's electric trucks can charge each other|url=https://www.engadget.com/2019-06-09-rivian-electric-vehicles-can-charge-each-other.html|access-date=2021-10-24|website=Engadget|date=9 June 2019 |language=en-US}}

{{Main|Hybrid train}}

{{Main|Ship#Propulsion_systems|l1 = Diesel-electric ship}}

The 2010 Wolverine 3 program included an ICE range extender for its unmanned aerial vehicle.{{cite web |url=http://articles.sae.org/8424/ |title=Secrets of Ricardo's new UAV engine may spawn range-extender for EVs |publisher=Society of Automotive Engineers International |first=Lindsay |last=Brooke |date=2010-06-21 |access-date=2015-11-22}}

File:Schema-Antriebe.jpg

A range-extended electric vehicle uses a series hybrid drivetrain.

• Hybrid vehicle drivetrain
• Microturbines
• List of hybrid and plug-in hybrid vehicles
• Diesel–electric powertrain

{{Reflist|30em}}

• {{Cite magazine |last=Marshall |first=Aarian |title=Automakers Are Hot for Extended-Range EVs. They Hope Buyers Like Them Too |url=https://www.wired.com/story/extended-range-electric-vehicles-erev/?bxid=5c748a433f92a46844a1deff&cndid=23448121&esrc=CMUnitPromo&hasha=2e93d119efeba3bbf6291108b8f9e56d&hashb=7a21f7cd2e86179af8d462a0828e40fac9486d03&hashc=8cc27749f183b99591f0c95a2858b11407066243cbe756e8e296e10fe7a5278f&utm_mailing=WIR_Daily_110324 |access-date=2024-11-04 |magazine=Wired |language=en-US |issn=1059-1028}}

Category:Vehicle technology

Category:Electric vehicles

Category:Plug-in hybrid vehicles