It seems on every corner at bauma 2019 someone was talking electrification – replacing diesel powered machines with battery powered electric drives. Among the reasons: legislative pressures for zero-emission vehicles in city centers, their suitability for indoor demolition and basement projects, and the preference for low-noise machines required for night-time work and in quiet zones such as hospitals, cemeteries and schools. On first glance the hydraulic systems on these machines are mostly unaffected by the switch from diesel to electric power. Here ‘s a look at five machines that were just introduced.
Bobcat has launched what it says is the world’s first 1 ton electric mini-excavator at bauma 2019. Combining zero emissions, low noise and a width of just 71 cm, Bobcat’s new E10e battery-powered, zero tail swing (ZTS) mini-excavator can easily pass through standard doors and in and out of lifts, making it ideal for indoor applications such as demolition and basement construction.
The zero-emission E10e is based on the diesel-powered E10 ZTS mini-excavator, which is a leader in the 1-ton category with over a fifth of the market share. The E10e has a state-of-the-art lithium-ion, maintenance-free battery pack with an advanced management system. Coupling the E10e to an optional external Bobcat supercharger while operators are on normal work breaks lets the E10e operate for a full working day; or it can continuously work for 4 hours on a single charge in standard working conditions.
The new E10e has the same ZTS profile, identical external dimensions, and equal or better performance. For example, the E10e offers very low noise levels on site at only 71 dBA vs 80 dBA for the standard E10. The electrohydraulic powertrain system fully uses the electric motor capabilities. It is equipped with auxiliary lines and an efficient oil cooler system for continuous hydraulic breaker operation. The machine also accommodates hydraulic pilot-pressure controlled joysticks. This design is unique in its class and is retained in the E10e, allowing the operator to enjoy the comfort and feel of much larger machines, while being able to adjust the width of the consoles for easy passage through narrow openings.
Komatsu, likewise, demonstrated an electric-motor/lithium-ion powered machine at their stand at bauma. It is based on a current, diesel-engine based machine, and it is being tested at customer sites in Japan. It’s based on existing Komatsu fork-lift and hybrid technology, and the only difference for the hydraulics is that it is driven by an electric motor. With a power rating of 18.5 kW, it has the same rating as the diesel version. Performance is the same in terms of digging power and speed – and in the crowded trade show, it ran virtually without discernable noise. However, it does have better stability as it weighs a bit more.
In light to medium-duty application conditions it will work for up to six hours. In extreme conditions, it may drop to as low as 2.5 hours before needing recharging. Developed on a fast-charging system, it can recharge in an hour. With standard power, it would need to recharge overnight. Komatsu officials have not said how price will compare to the conventional machine, only stating that it will be more expensive.
Volvo Construction Equipment has unveiled two zero-emissions machines – the ECR25 excavator and L25 wheel loader. The machines, the first in a new electric range of Volvo branded compact excavators and compact wheel loaders, deliver zero exhaust emissions, significantly lower noise levels, reduced energy costs, improved efficiency and less maintenance requirements, compared to their conventional counterparts.
To make the ECR25 and L25 electric, the combustion engines have been replaced with lithium-ion batteries. The ECR25 is fitted with lithium-ion batteries and one electric motor which powers the hydraulics in order to move the machine and the attachment. The machine’s batteries store enough electric energy to power the ECR25 for eight hours in its most common applications, such as utility work. The L25 incorporates lithium-ion batteries which allow for eight hours of operation in the machine’s regular applications, including light infrastructure work, gardening, landscaping and agriculture.
The L25 also incorporates two dedicated electric motors, one for the drivetrain and one for the hydraulics. Decoupling the subsystems has led to higher efficiency in both the systems and the entire machine. Both the ECR25 and L25 have onboard chargers that enable overnight charging via a regular household plug socket. A fast charging option, requiring more powerful grid access, will also be available.
Wacker Neuson is expanding its zero emission products that, they say, make no compromises regarding performance or available running time. Among the new introductions is a new zero tail mini-excavator EZ17e.
“Due to the tightening question of emissions, in particular within the inner-city area, we are seeing an increasing demand for emission-free solutions. The new electric mini-excavator is a real alternative to the conventional machines when working in areas sensitive to sound and emissions,” said Alexander Greschner, sales director of the Wacker Neuson Group.
Due to their compact dimensions (the battery has been integrated into the motor compartment), the electric excavator can operate in confined conditions and offer more freedom of movement. This means that the operator does not have to worry about damaging the machine while working close to walls or in confined spaces. The rear of the excavator never protrudes beyond the undercarriage. The EZ17e is excellent for tunnel construction applications, demolition and reconstruction or repair work, and interior room restorations.
The electric excavator’s lithium-ion battery can be charged simultaneously at a household socket or at a mains power connection (express charging process), which increases the machine’s running time over the whole workday. The machine also maintains its weight class, inclusive of the battery, and can thus continue to be transported on a car trailer. The zero-tail mini-excavator EZ17e will go into production in 2019 and be available in the autumn.
Kobelco displayed its all-new 1.7-ton electric mini excavator concept. The unit builds on previous developments in hybrid and electric technologies, such as the iNDr (Integrated Noise and Dust Reduction Cooling System) and innovative hydraulic systems for promoting low fuel consumption.
The 1.7 ton electric-powered 17SR mini excavator concept reportedly combines Kobelco’s expertise in developing highly efficient construction machinery for urban jobsites and Deutz’s superior electric drive technology. Together, this combination will enable the electric powered 17SR to deliver zero emissions, extremely low noise operation and reduced life cycle costs.
The company’s objective is to manufacture a fully-electric mini excavator that will be capable of performing at the top of its class, with a long-life battery for utmost convenience. With this in mind, Kobelco expects the 17SR to launch in 2021. The company’s long-term objective is to further expand its machinery line-up to include more advanced technologies, including electric-driven excavators, in its pursuit of promoting a sustainable society.