Electric Cycles: Stepping Up Pedal Power

Munich. Once upon a time, motorized bicycles were only for pensioners. Today, however, their popularity is soaring as electromobility develops into a major issue. The cycles, known as pedelecs (Pedal Electric Cycles), have taken on the status of trendy, eco-friendly alternatives to cars for city-dwellers, and the market is booming.

While around 150,000 cycles with electric auxiliary drives were sold in Germany in 2009, sales for this year will significantly exceed 200,000 units. E-bikes are also a prominent theme at Eurobike, the trade show held in Friedrichshafen from 1 – 4 September. But what should powered pedallers watch out for when choosing their purchase? The experts at TÜV SÜD have assembled a list of tips.

The idea of boosting cyclists' muscle power along with an auxiliary motor is almost one hundred years old. In the early days combustion motors helped cyclists to climb every mountain; today, the two-wheelers that take them to the top are known as pedelecs or e-bikes and are fitted with electric motors. Cyclists seeking that little extra assistance need not pay more than for a conventional cycle. "Pedelec prices range from 800 to 4,000 euros", advises Michael Winter, TÜV SÜD's e-mobility expert. Range, purchase price, environmental consideration, battery, laws and regulations and so on – purchasers prepared to invest in powered pedalling should familiarize themselves with the main issues involved.

Pedelecs: In legal terms, pedelecs are bicycles. "Under EU law, they are not subject to any restrictions or obligations concerning registration, driving licences or wearing of helmets", explains Winter. Pedelec motors have a maximum nominal output of 500 watts and operate solely as an auxiliary support, switching off automatically at speeds of over 20 kilometres per hour. Faster speeds, however, need the extra kick of muscle power – just like conventional bicycles.
 E-bikes: However, different regulations apply to "e-bikes" in Germany, which require an operating licence in accordance with Article 21 of the country's Road Traffic Licensing Regulations (StVZO) or a comparable EU operating licence and insurance number plate. The technical difference is that like a moped, the motor of an e-bike is operated solely by a twist-grip throttle, and is independent of any pedalling by the rider. Motor and muscle power are therefore two separate and independent drive systems.

E-bikes can be operated in "mixed" mode or pedalled only just as pedelecs can, but can also be used with engine power only. And like mopeds, e-bikes require users to have a driving licence regardless of category (minimum: moped licence as per Art. 5 of the German Driving Licence Regulations (FEV).

Battery: The rechargeable battery is the most important component of a pedelec, supplying the necessary power to boost the cyclist's progress. Prospective purchasers should therefore pay particular attention to this aspect. Developments in battery technology in recent years have led to improved performance and reduced weight – both of which play a major role for the rider in terms of convenience and range. While nickel cadmium (NiCd) or nickel metal hydride (NiMH) batteries are still occasionally found, e-cyclists should go for lithium-ion (Li-Ion) batteries as the current state-of-the-art technology. Unlike the older battery types, these batteries have a significantly higher energy density (around twice as high as NiCd batteries and over 50 per cent higher than NiMH batteries) and no longer suffer from the "memory effect" which results from irregular charging cycles and incomplete discharging and which significantly impairs performance. Lithium-ion batteries thus have a considerably longer operating life, on average three to five years.

Charging time: The number of potential charging cycles and the lifespan of a battery are determined not only by the quality of the battery cells, but also by the charging method. Manufacturers specify battery lifespan in terms of full charge cycles, with an average battery having a life of around 500 cycles. At a (purely electrical) range of 30 kilometres, one battery represents 15,000 kilometres of travel. Lithium-ion batteries have the advantage that the volume of current determines the battery life; if the battery is only charged halfway this corresponds to half a charge cycle, whereas for other battery types each time of charging represents a charge cycle. Nevertheless, the charging capacity of even the most modern batteries declines with every charging process. Charging devices that charge slowly are kinder to batteries. Battery life can also be extended by charging the battery in a warmer environment; charging in an ambient temperature of under ten degrees Celsius puts greater strain on the battery.

Spare batteries: When purchasing your cycle, it is wise to consider buying a spare battery at the same time. In addition to keeping you mobile while the first battery is charged, a spare battery extends overall cycling pleasure: rechargeable batteries that operate at 85 per cent of their original capacity are generally classified as worn-out, and this may happen after only three years. It is therefore important to factor in aspects such as warranty conditions and costs of battery replacement when considering your purchase. "Replacing a battery after three years can be a very expensive undertaking", warns Winter – the costs average 600 euros.

Range: Battery, weight, pedalling force and road conditions are all factors that impact on the range of an electric cycle – a further key issue in making a purchasing decision. How long can I travel before needing to recharge? Even if powered assistance is not necessary, pedalling an e-bike or pedelec is harder work than a conventional cycle, since the additional weight of the electric motor also has to be moved along. "Manufacturer's range specifications vary from 15 to 80 kilometres", says Winter, but warns that the maximum ranges are almost never achieved. This is due to a variety of reasons; in addition to battery output and motor efficiency, the assistance factor has a major impact on the range; users who expend their own effort into riding will ride for longer. Many models, however, enable the assistance factor to be set manually, so that the range of travel varies depending on these settings.

Safety: E-bike or pedelec – as with normal bicycles, a helmet is an essential element for travel safety, even though not yet required by law.