Electric scooter

from Wikipedia, the free encyclopedia

An electric scooter , also known for short as an electric scooter , e-scooter or e-scooter , is a scooter with an electric drive . The energy supply comes from a traction battery with several accumulator cells . With increasing popularity, electric scooters are sometimes also referred to as electric scooters , e-scooters or e-scooters .

Beginning of development from the 20th century to the 2010s

An "E-Max" at a rental company
Swedish nostalgic electric scooter 1

The first electrically powered two-wheeler existed as early as 1911. From the 1950s onwards, many small workshops and hobbyists, but also well-known companies such as Puch and Peugeot , tried to bring electrically powered scooters onto the market. While many Puch vehicles are no longer in everyday use, almost all Peugeot Scoot'Elec produced since 1995 are still in everyday use.

The history of e-scooters began in factory halls, where small transport scooters were needed for goods and people and internal combustion engines could not be used due to the exhaust gases. In recent years, an extensive range of electric motor scooters (also known as electric scooters) has emerged on the market, with models that today have a range of around 50 km (with higher-quality battery technologies of over 100 km) and a speed of around 45 km / h or up to over 80 km / h.

Typology and characterization

Driving license and type approval

Electric scooters are offered in various EC vehicle classes. A driver's license is required to drive them . The following requirements must be met.

Germany

  • Light moped, e.g. B. MZ Charly from MZ / MuZ, up to 20 km / h and helmet-free. Depending on age, test certificate for mopeds.
  • Mopeds: E-mopeds from Solo and Herkules from the 70s. With helmet compulsory up to max. 25 km / h
  • Small motorcycle L1e up to 45 km / h top speed at least with a driving license M from 16 years or B
  • Light motorcycle L3e up to 80 km / h top speed:
    • Grade 3 or 4 (acquired before April 1, 1980),
    • Class 1b (acquired after April 1, 1980) or
    • of class A1.
  • L3e motorcycles / motorcycles with or without a sidecar driving license class A

Electric scooters must meet the national technical requirements for motor vehicles (e.g. two independent braking systems, lighting system, horn, tires). The EU directive 2002/24 / EU for motor vehicle law states that all electric vehicles, with the exception of pedal-assisted bicycles, are considered motor vehicles (up to 45 km / h as L1e moped). You therefore need a national type approval. An EU approval ( general operating license ) requires a national type approval. A CoC (a so-called certificate of conformity, CoC paper, Certificate of Conformity, Certificat de conformité) is not sufficient.

Switzerland

In Switzerland, vehicles up to a maximum of 45 km / h are referred to as category F e-scooters or electric scooters and are accelerated with a handle like a moped. A helmet, license plate, driver's license and insurance are required. Some of the many small e-scooters available are legal at lower speeds, but most are not allowed at all, except on private property.

Austria

In Austria, electrically powered single-track vehicles with an engine output of max. 600 watts and a design speed of no more than 25 km / h as a bicycle, see Bicycle Ordinance .

Advantages and disadvantages of the electric scooter

The main advantages of e-scooters compared to conventional scooters are:

  • low noise
  • no exhaust
  • Less maintenance: By eliminating the internal combustion engine, clutch and variable speed gear, there are fewer wearing parts.
  • low operating costs and effort
  • no increased engine wear with frequent use on short journeys
  • no dependence on fossil primary energies for fuel; more ecological in relation to the overall environmental impact (greenhouse gas emissions in CO 2 equivalents for distances to be covered in everyday life: e-scooter 7 kWh el / 100 km: 18 g CO 2 eq / km; for comparison: four-stroke motorcycle 5.6 l / 100 km: 208 g CO 2 -eq / km)
  • Charging is possible at home or practically at any other socket.

Disadvantages of the electric scooter:

  • high purchase price
  • Long charging time compared to refueling
  • shorter range
  • high weight (especially with lead batteries)
  • in many regions poorly developed charging infrastructure (public facilities, parking lots, etc.)
  • In order to optimize the service life of the battery, the performance of most models is often weaker than that of comparable vehicles with a combustion engine, which is particularly noticeable when driving up inclines, especially with heavy lead-acid batteries as traction batteries
  • As wear parts, batteries have a limited lifespan. If handled incorrectly, they can lose capacity or fail well before the calculated service life.
  • Replacement batteries are quite expensive and can make up just under half of the vehicle price for some models
  • Use in winter is only possible to a limited extent, as the usable capacity of the batteries is reduced in extreme cold.

Charging stations

The use of electric charging stations , together with adapted chargers, can open up completely new perspectives for the distance that can be covered, but is less necessary for e-scooters than for electric cars . A problem for all electric vehicles with higher traction battery capacities has so far been that on the household power supply (230 V / 10 A or 16 A) with the mains plugs that are available everywhere, only a charging power of up to 2.3 kW can usually be used. With Schuko sockets, which are common in Germany and Austria , only a continuous current consumption of 10 A (only briefly 16 A) is permitted; Swiss households, on the other hand, are usually protected with 10 A ( SEV 1011 , T1x). The full power of 16 A / 3.6 kW can be used via a charging plug according to IEC 60309 (caravan plug) . For currently common traction batteries in e-scooters with storage capacities of 1.5 kWh - 5 kWh ( Vectrix VX-1 Li), accelerated charging can be carried out at household sockets in 45 min - 2 h: 30 min, with caravan sockets in 25 min - 1 h: 25 min. The available traction batteries can handle the necessary charging currents. However, the effort for correspondingly powerful chargers as well as for monitoring and control increases.

Commercial charging stations provide connections for significantly higher charging capacities. On the vehicle side, suitable chargers , quickly rechargeable batteries ( e.g. certain LiFePO 4 battery variants or similar) and a compatible cable / plug combination (with a plug according to IEC 60309 or IEC 62196 ) must be carried on board for faster charging . In Germany, the Mennekes plug is favored. Its transferable power of up to 43 kW can only be used to a very limited extent with the electric scooter. This connection option is advantageous for charging stations that no longer offer a household or caravan connection for normal household electricity (230 V / 16 A), although this is the minimum standard connection for all electric vehicles.

The complete integration of a fast charging system (in the chassis or in the frame) is less of a technical challenge than a cost aspect for the manufacturer. Most electric scooter models currently do not contain such a feature, mainly for cost reasons (as of 2012).

Rental systems

Since the triumph of small electric vehicles, rental systems ( e-scooter sharing ) have developed in various large cities . As of summer 2018, there should be around 20,000 rental e-scooters worldwide, for which more than a million users have registered.

Six providers each have established themselves in Milan, Madrid and Barcelona. In Paris there were initially four (including the start-up Cityscoot ) and two in Berlin: Emmy , a Berlin start-up that the state-owned investment bank Berlin has invested in , and Coup , founded by Bosch . Coup , represented in Berlin with 1,000 electric scooters, then expanded to Tübingen, Paris and Madrid, where 1,700 and 850 scooters respectively had been brought by the end of June 2018. The number of registered users for the Emmy is 50,000, for which 600 scooters are available; 200 scooters are to be added by the end of 2018. Emmy started in 2015 with 5,000 users. Despite the great popularity of customers, it has not yet been proven that business with rental scooters can be operated profitably, especially if several providers are active in one city - in November 2019, Coup announced that it would cease business by the beginning of 2020 due to a lack of profit prospects in all cities .

technology

drive

Self-made scooter with toothed belt

With the mass of scooters, brushless DC wheel hub motors have practically established themselves as the standard. Their position in the rear wheel reduces space requirements and the number of parts for the drive, but increases the unsprung mass. For this reason, some devices also use motors that transmit their power to the rear wheel via a toothed belt , for example the E-Vivacity from Peugeot. Chain drives are rarely found.

Batteries

In the area of ​​e-scooters, as in other areas of electromobility , energy storage devices, especially in the form of traction batteries / accumulators, are a central element of intensive development work. The different types widespread in the 2010s are either permanently installed by the manufacturer or provided as removable battery packs . They all require charging processes and control modules that are tailored to the respective number of cells, battery chemistry and nominal voltage. Even within lithium technology , different nominal voltages require careful exchange.

The useful capacity of accumulators is temperature-dependent and, in connection with the physicochemical properties of the electrolyte and electrodes (reduced electron mobility), takes on significantly lower values ​​than at room temperature. To reduce this effect, the accumulators can be heated when it is cold.

The service life of the batteries is decisive for economical operation. It can be described by the amount of charged and withdrawn energy, the number of charging cycles (full and partial cycles) or the calendar life. In the case of a scooter, this can also be expressed by the mileage per battery pack. All of these details are related to one another and can be influenced to a large extent by the technical design, environmental conditions and usage behavior. It shows that battery cells that are used with flat charging cycles and low currents in relation to their capacity and are rarely operated at the upper and lower limit voltages achieve the longest service life. Ranges of more than 50 km can only be achieved with large capacities (in Wh). A positive side effect for the service life is that, with the same motor power, the battery cells are loaded with lower discharge currents than is the case with smaller battery packs.

The manufacturers often state the nominal capacities of lead batteries for unrealistic discharge times between C3 (3 hours) and C20 (20 hours), with lithium technology C1 or C0.5 values ​​are common. However, depending on the motorization and driving style, in reality significantly higher discharge currents can occur with electric scooters, which means that the capacity of the batteries does not reach the nominal capacity. This phenomenon is known as the Peukert effect .

Cheap electric scooters are mostly with lead-acid batteries equipped - often as an indication of the in silicone bound electrolyte effective in advertising as a "modern silicon battery" means. Disadvantages are the even lower real capacity under load, their short service life of around three years and, above all, their weight and size. Most of these electric scooters have a maximum range of around 50 km / charge and cause higher kilometer costs due to the need to change the battery. Lead-acid batteries can withstand about 350 full charge cycles before they become inoperable.

High-quality electric scooters were initially equipped with NiCd (for example: Scoot'elec ) or NiMH batteries (for example first generation Vectrix VX-1 ). These moved to lithium-based batteries.

A significant reduction in weight and an increase in range can be achieved with lithium-ion batteries , for example as lithium-polymer batteries or lithium-iron-phosphate batteries (for example: Kumpan electric ). The disadvantage is the significantly higher acquisition costs: € 300 to € 1,400 more than a scooter with older battery technology. Advantages are the higher load capacity, both when loading and unloading (driving) and the better handling due to the lower weight. For lithium-ion batteries , the technical information provided by the manufacturer generally relates to half the current strength of the cell capacity (0.5 C), which corresponds better to the usage profile in e-scooters.

LiFePO 4 batteries can achieve over 1000 full charge cycles. As a rule, however, the batteries are used in partial cycle operation, which enables a significantly higher total number of cycles within the service life (LiFePO 4 : 3000 cycles at 80% DOD, 5000 cycles at 70% DOD, manufacturer information for single cells). Lithium-ion and lithium-polymer batteries range in between.

Battery management systems and balancers

Although even with older battery technologies based on lead or nickel, the drifting apart of the cells of a traction battery often led to premature failure, compensating systems for electric scooters were and are not available from the manufacturer. With these traction batteries, cell drift is usually countered by means of appropriate charging programs, which are intended to bring the charge states of the cells into line by means of targeted overcharging within permitted limits. Overcharging leads to cell heating and, in the case of liquid electrolytes, to gases.

Due to the high sensitivity to overcharging, incorrect treatment, strict manufacturer specifications and constant further development of power electronics, battery management systems (BMS) are used in batteries made of lithium technology . In addition to temperature control, diagnostics and range determination, these take over charge and discharge control. A balancer function is also integrated, which compensates for the inevitable cell drift. The quality of this electronics has a strong influence on the long-term performance and service life of the battery cells. A good BMS rules out incorrect handling due to environmental influences (e.g. temperature limits) and use (e.g. current flow and voltage limits) and thus prevents damage and excessive wear on the battery. In addition, it informs the user and often offers the functionality of an on-board computer .

Energy recovery (recuperation)

A recuperation , or regenerative brake , the energy recovery by converting kinetic energy from downhill driving and braking into useful energy while utilizing the inertia of the moving vehicle, increases the range of the electric scooter per charged battery charge. It requires a motor controller that can use the drive motor not only in the motor but also in the generator area to charge the traction battery, as well as suitable motor technology.

In contrast to electric cars , recuperation is not generally used in electric scooters, mainly for reasons of cost. This can change, as electric scooters are also increasingly measured by their economic efficiency with increasing economic pressure. On the one hand, the recuperation protects the battery system of an electric scooter, which contributes to its profitability, on the other hand, it increases its initial purchase price (due to the manufacturer's development and production costs).

Manufacturer

Most of the electric scooters are produced in China and Taiwan today. Some European manufacturers have essential parts of their vehicles manufactured in China.

Electric scooter manufacturer in Germany

Samson

ELMOTO HR-2

From 1992 presented Simson the electric scooter SR50 E or E gamma ago. The development of the electric motor was completed in 1989 in the GDR , but the vehicle was only produced in small numbers. Range (max. 50 km) and price (5,000 DM) were progressive, but evidently not sufficiently attractive for the customer base at the time.

ID bike

The Stuttgart-based company ID-Bike GmbH has been developing and producing the ELMOTO HR-2 since 2009 : This is an electric light motorcycle with a top speed of 47 km / h, a range of 65 km and a weight of 47 kg. In July 2018, Govecs took over the assets of ID-Bike.

Govecs

GOVECS E-Schwalbe in Berlin

Munich-based Govecs , founded in 2009, develops and produces electric scooters in its plant in Wrocław, Poland . One focus is on electric scooters for the (food) delivery industry and for two-wheeler sharing companies such as B. emmy in Germany, Cityscoot in France, Felyx in Holland or eCooltra in Spain and Italy. The company sells its electric scooters from GOVECS GO! Series in Europe and the USA. In 2016, GOVECS, in cooperation with Robert Bosch GmbH, presented a remake of the " Schwalbe " as an e-scooter with a range of over 100 km, a motor output of 4 kW and a top speed of 45 km / h. Sales started in summer 2017 . Production of the Schwalbe as a light motorcycle version with 8 kW engine power and a top speed of 90 km / h will start in summer 2018.

The vehicle had previously been developed by efw-Suhl GmbH at the location of the former Simson plant and the market launch was originally announced for 2011. However, the developer at the time did not succeed in enabling series production and the start of sales had to be repeatedly postponed. In 2014 GOVECS finally took over the project.

MW Zschopau

The MZ Charly , an electric folding scooter from Motorradwerke Zschopau GmbH , is also manufactured in Germany . It is single-seated as a moped and is limited in speed.

e-bility

E-bility GmbH , based in Remagen, has been manufacturing the Kumpan electric scooter since 2010 . There are three models on the market: 1950 , 1953 and 1954L , both one and two-seater. The 1953 and 1954L scooters have a motor output of 2 kW (2.7 HP), have a brushless wheel hub motor and various technical functions such as cruise control or the boost function. The new generation is equipped with lithium-ion batteries (51 V / 29 Ah per battery), which can be connected in parallel and are removable. With three batteries connected in parallel, the range can be increased to up to 150 kilometers, according to the manufacturer.

In 2015 a scooter was added, also with a wheel hub motor on the rear wheel and like the larger models with a top speed of 25 km / h.

BMW

BMW C evolution

In 2014, the BMW C Evolution, the most powerful scooter to date, came onto the market: With a top speed of 120 km / h, a peak output of 35 kW and a rated output of 11 kW, it is not a classic scooter , but rather a a motorcycle . With a price of 15,000 euros at the start of sales, the C Evolution was also the most expensive production scooter to date (see list of electric scooters ).

Unu

Unu roller

The Berlin- based company Unu has also been selling a scooter made in China with a 1,000, 2,000 or 3,000  watt motor in the rear axle since 2014 . After the introduction in Germany, sales were also expanded to Austria, Switzerland in 2015, the Netherlands in 2016 and France in 2017. In Germany, the 45 km / h moped is the market leader in the electric scooter segment.

Electric scooter in Austria

IO Florence electric scooter, special model from Linz AG, at a public charging station

IO scooter

Electric scooters from the Brunn am Gebirge- based company IO Scooter are quite common in Austria , with several different models being offered. The smallest model Scooby with an engine power of 600 watts and a maximum speed of 25 km / h is considered a bicycle according to Austrian law and can therefore be driven by persons aged 12 and over without registration, insurance and driving license (including when accompanied by an adult) . The 1500GT, Florenz and Vienna models, with an engine output of 1.5 to 3 kW and a top speed of 45 km / h, fall into the L1e vehicle class. In addition, the Vienna XE, King Kong and Manhattan models are three vehicles in the 125 cc class (L3e) with top speeds of up to 80 km / h.

Electric scooter in France

Scoot'elec from Peugeot

Between 1995 and 2005, a Peugeot electric scooter was built in Europe . It had a range of around 40 km and a charging time of around two hours from any normal socket. The battery consisted of 3 STM-5-100-MR-NiCd batteries from Saft with 100 Ah and 6 V - 1.8 kWh. The energy consumption was 6-8 kWh per 100 km with an engine power of 2.8 kW. The weight of the two-seater, which cost around € 3,450 at the time, was 115 kg with battery. The battery life was specified as 2,000 charging cycles (80,000 km), after which 80 percent remaining capacity could be achieved.

Peugeot stopped production at the end of 2005. The last vehicles were delivered in Germany until mid-2006. The reason for the setting was the high cost of a new control unit, which, unlike most Chinese scooters , could switch 500  amps (a comparable one for forklifts with currents of up to 1,000 amps costs around 2,000 euros). However, all replacement and replacement parts were available until at least December 2008. The successor model is the e-Vivacity with LiIon battery .

Electric scooter in the Netherlands

Trikke

The Trikke eV6.1 has been available on the German market since mid-2014 . It is street legal , has a total weight of almost 24 kg and a top speed of up to 25 km / h. With one battery charge, ranges of up to 40 kilometers can be achieved, the battery can be changed without tools.

Electric scooter in Poland

Vectrix

The Vectrix VX-1 scooters by Vectrix Corporation , which have been produced in Poland since 2007, marked the upper performance range for electric scooters with a top speed of 110 km / h and a peak power of around 20 kW until the BMW C Evolution was launched in 2014. In contrast to the majority of scooters in Germany, which are limited to 45 km / h, these vehicles are not classified as mopeds, but as motorcycles or motorcycles.

Electric scooter in Spain

MUVI from Torrot Electric

The MUVI is an electric scooter that the Spanish company Torrot Electric, based in Girona , Spain, launched in 2016. The 2 models City and Executive are currently available, which differ in their engine power (2.65 kW or 3 kW) and top speed (45 km / h or 60 km / h). Both versions have two removable lithium-ion batteries with a total capacity of 2.4 kWh. According to the manufacturer, the range is up to 85 km.

Electric scooter in china

The low prices and the fact that they are considered bicycles there made e-scooters very popular in the PRC even before 2010.

Chinese everyday life: parked e-scooters

China is the first country to sell more electric vehicles than gasoline vehicles for the first time in 2006 (19 million electric vehicles, 13.4 million gasoline vehicles). The electric scooter is now part of everyday life like the famous Chinese bicycle 20 years ago. In some large cities and metropolitan areas such as B. Guangzhou including the surrounding area, scooters with internal combustion engines are prohibited.

Operating costs and mileage costs

introduction

The pure operating costs as consumption costs are very low with the electric scooter. They are determined by the electricity costs, but only represent a small part of the kilometer costs / actual total costs.

At today's electricity prices (as of 2012, Germany: around € 0.25 / kWh), the operating costs for a 100 km journey are around € 1. In winter or when not in use for a longer period of time, there may be additional electricity costs for battery heating or maintenance charging. By using an external timer, charging and battery heating can be activated in good time before use and additional energy consumption can be minimized. Other operating costs such as oil consumption, vehicle washing and maintenance costs are usually not incurred or are insignificant.

The kilometer costs include all costs for the use of the scooter, broken down into the kilometers driven. In addition to the technical design, they are very much dependent on the annual mileage (user profile) and user behavior. The following applies:

Kilometerkosten = (Betriebskosten + Fixkosten + Werkstatt/Reifenkosten + Abschreibungskosten) / Gefahrene Kilometer.

Fixed costs

The insurance costs for the legally required motor vehicle liability insurance are around € 60 per year. The costs for comprehensive insurance are optional. A vehicle tax is only due (in Germany) if the e-scooter is not approved as a small motorcycle according to EC vehicle class L1e or L2e . Scooters with higher quality battery types are often (partially) rented out. The rental costs are then part of the fixed costs.

Workshop / tire / battery costs

The workshop costs are lower than with comparable scooters with internal combustion engines , since, for example, regular oil and spark plug changes are no longer necessary, as is most of the adjustment and maintenance work on mechanical components (clutch, gearbox). Brake wear is significantly lower on scooters with recuperation .

The tire costs are comparable to other scooters and are determined by the performance and driving style.

With the e-scooter, costs may arise due to the wear part of the traction battery , which can differ greatly in terms of technical design, user profile and user behavior. If the traction battery needs to be replaced during use, additional costs will apply. They can be described for each kilowatt hour taken. The order of magnitude for these costs is approximately for open NiCd batteries at 2,000 cycles = 0.30 € / kWh; NiMH batteries at 1,000 cycles = € 0.80 / kWh; for lead batteries wound for low internal resistance with 200 cycles = 1 € / kWh; LiFeYPo4 batteries at 1,000 cycles = € 0.50 / kWh. Depending on the type and size of the battery, the consumption of the scooter in kWh / km and depending on the need to replace the batteries, the battery wear and tear can have a significant impact on the cost per kilometer.

The user profile has a strong influence on battery wear. Regular use (driving to work) without utilizing the maximum range, battery or motor power provides the most favorable basis for a long service life and thus low kilometer costs. Low annual mileage and irregular use, on the other hand, can lead to significantly higher costs per kilometer, since batteries lose performance and age faster even if they are not used, lack maintenance and have an unfavorable state of charge during longer breaks in use. The problems of winter temperatures known from car starter batteries apply analogously to lead-based traction batteries and also lead to a reduced current-carrying capacity for lithium batteries.

On the other hand, battery wear can be reduced by driving in a way that is easy on the battery, especially with lead-acid batteries by (frequent) voluntary range limitation to 30% and immediate recharging to 100%. In the case of lithium- based batteries, for example lithium iron phosphate accumulators , a discharge below 20% should be avoided, which is ensured by the battery management system regardless of the user if the technology is fully developed . In winter, battery heaters come into consideration in order to guarantee the current carrying capacity.

Depreciation costs

The acquisition costs for a scooter range between € 1,000 and € 4,500 for models with a top speed of 45 km / h. In order to be able to buy an equivalent e-scooter at the end of its useful life without external financing, the purchase price must be saved again or the savings rate must be allocated to the kilometers driven.

See also

See however

literature

  • Niels Fries: Practical manual for electric scooters. Mobility for an environmentally friendly future. Books On Demand, Norderstedt 2008, ISBN 978-3-8370-6062-1 .

Web links

Commons : Electric Scooters  - Collection of Images

Individual evidence

  1. ElectromotorcyclesTemplate: dead link /! ... nourl  ( page no longer available )
  2. ^ Environmental benefits of e-scooters. ( Memento from July 1, 2011 in the Internet Archive ) (PDF)
  3. Claudius Prößer: e-scooter boom in Berlin: Real electrifying. The e-scooter business is flourishing in Berlin. The provider benefits from the fact that the authorities turn a blind eye at a crucial point. www.taz.de, July 20, 2018, accessed on July 22, 2018 .
  4. a b Jochen Knoblach: Green wave . In: Berliner Zeitung , July 16, 2018, p. 15. (print edition).
  5. Supplier of electric scooters gives up . In: Berliner Zeitung , November 26, 2019, p. 12.
  6. Winston Battery: Specifications WB-LYP100AHA , accessed June 24, 2013.
  7. ID-Bike GmbH: Quality, Made in Stuttgart. ( Memento of August 25, 2013 in the Internet Archive ) accessed on September 7, 2013.
  8. GOVECS takes over ELMOTO . ( govecsgroup.com [accessed September 12, 2018]).
  9. GOVECS GROUP - Home. Retrieved September 12, 2018 .
  10. GOVECS GROUP - Industries. Retrieved September 12, 2018 .
  11. myschwalbe.com (October 6, 2017)
  12. Uli Baumann: Govecs Schwalbe 2018 light motorcycle . ( motorradonline.de [accessed September 12, 2018]).
  13. Summer without the E-Schwalbe. In: Berliner Zeitung. July 19, 2011, accessed August 22, 2012.
  14. Schwalbe turns 50 - E-Schwalbe is still in labor. ( Memento of June 8, 2014 in the Internet Archive ) In: MDR. June 4, 2014, accessed August 18, 2014.
  15. EICMA 2014: The E-Schwalbe now comes from Govecs. In: motorsport-total.com. November 11, 2014, accessed February 11, 2016 .
  16. Motorradwerke Zschopau GmbH: Charly Evo. ( Memento from February 11, 2013 in the web archive archive.today ) accessed on August 22, 2012.
  17. Why Kumpan electric scooter? - Kumpan Electric . In: Kumpan-Electric . ( kumpan-electric.com [accessed June 7, 2017]).
  18. Kumpan electric
  19. a b c C EVOLUTION. (No longer available online.) In: bmw-motorrad.de. Archived from the original on March 4, 2016 ; accessed on February 11, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.bmw-motorrad.de
  20. 1506 unu Expansion Austria DE.pdf. via the company's press website. (No longer available online.) Archived from the original on April 3, 2017 ; Retrieved April 2, 2017 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / unumotors.com
  21. 1511 unu Expansion Schweiz DE.pdf. via the company's press website. (No longer available online.) Archived from the original on April 3, 2017 ; Retrieved April 2, 2017 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / unumotors.com
  22. 1612 unu Expansion Netherlands DE.pdf. via the company's press website. (No longer available online.) Archived from the original on April 3, 2017 ; Retrieved April 2, 2017 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / unumotors.com
  23. Mobility startup Unu: Electric scooters are just the beginning . In: t3n News . ( t3n.de [accessed June 30, 2017]).
  24. The unu success story - in just four years from the first idea to the award-winning electric scooter start-up . In: Der Tagesspiegel Online . March 8, 2017, ISSN  1865-2263 ( tagesspiegel.de [accessed May 4, 2018]).
  25. Registration & Insurance. (No longer available online.) In: trikke.de. Archived from the original on February 18, 2016 ; accessed on February 11, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.trikke.de
  26. TRIKKE? TRIKKE! In: e-action.center. Retrieved February 11, 2016 .
  27. MUVI - Torrot Germany. Accessed January 2, 2017 (German).
  28. ↑ No more Vespa. In: Süddeutsche Zeitung. September 20, 2010, accessed June 9, 2013.