PRODUCT FOCUS
To make the EX2 prototype fully electric,
the combustion engine has been replaced
with two lithium ion batteries, totalling
38kWh, which store enough electric energy
to operate the machine for eight hours in an
intense application, such as digging compact
ground. The hydraulic architecture has also
been replaced with electric architecture,
which incorporates electromechanical
linear actuators that help to optimise the
transmission chain. Removing the hydraulic
system and the combustion engine, as
well as reducing the cooling needs, has led
to significantly lower noise levels, while
decoupling the subsystems, as well as using
highly efficient actuators and power sources,
increases total machine efficiency and
controllability.
“The electrification of construction
equipment will produce cleaner, quieter, and
more efficient machines — this represents
the future of our industry,” says Ahcène
Nedjimi, electrics and electronics systems
lead engineer and EX2 project leader. The
EX2 is a revolutionary machine. With its zero
emissions and 10 times lower noise levels,
it could easily be used in densely populated
areas without disturbing people — even at
night. Ten times higher machine efficiency
and maintenance-free systems mean that
operating costs and total cost of ownership
would be significantly reduced.
“Because the EX2 is fully electrified
and there are no mechanical joysticks, it
can be controlled remotely from a mobile
phone or tablet,” Nedjimi continues. “This
increases safety in hazardous working
environments. Additionally, the EX2 delivers
the same power and force as its conventional
counterpart, as well as faster speeds in
combined movements. As this type of
movement is the most common kind for this
machine, productivity is improved. All of this
has been achieved without compromising on
machine performance, ensuring customer
needs would be fulfilled.”
The EX2’s efficiency means that average
power consumption is comparable to that of
a large iron (3.5kW), significantly reducing
operating costs and total cost of ownership.
The machine also does not require any
power when in idle mode, which adds
to the significant reduction in operating
costs since this type of compact excavator
usually spends approximately 40% of its
time in idle mode on a job site. The lack of
engine or hydraulics reduces maintenance
requirements, while the lower cost of
electricity compared to diesel means that
fuelling a fully electric machine will reduce
operating costs. The EX2 can also recover
energy; its fully reversible system means
that energy is recovered when the boom is
lowered and the cab is rotated.
The EX2 has been designed to work in four
different ways. It can be fitted with two 600V,
19kWh lithium ion batteries, which last a
minimum of four hours each (a total of eight
hours) if the machine is continuously digging
(trenching cycles, which are not the main
operation for this type of machine — they
are usually only operated for around three