When it comes to alternative-powered construction equipment , there ’ s little doubt that electric-powered compact machines have gained the most traction .
“ The 48-volt battery packs and the duty cycles of compact machines are well matched ,” said Ray Gallant , vice president of product management and productivity for Volvo Construction Equipment , which has five electric models either in production or announced for the North American market .
“ From a technological standpoint , electric-powered compact equipment was one of the easiest to go after ,” said Chris Lucas , product manager for excavators , JCB North America , which debuted its 19C-IE electric compact excavator in 2019 .
“ Considering compact equipment can be operated with a smaller battery size at lower voltage , we plan to make a shift to battery-type excavators for 10-metric-ton and below ,” said Thomas Jaejin Lee , director of product management , Doosan Infracore North America .
The Rise of Electric Power The use of electric power in construction machines is not new . Electric-powered machines have had a long run in the mining , demolition , aerial lift and industrial forklift segments . But now they ’ re making their way onto general jobsites .
Electric construction machines were a trade show curiosity as little as six years ago . Now compact equipment manufacturers expect to be questioned on whether they are working on an electric model .
Much of the electric model work has centered on the compact excavator , with manufacturers using either internal design capabilities or partnering with companies such as Green Machine , Moog Construction and WhisperDrive to create an electric version of a current diesel unit .
An Intriguing Alternative Most current electric models are electric / hydraulic , in which a lithium-ion battery replaces the diesel engine and powers an electric motor and conventional hydraulics .
But an intriguing alternative is now also on the market : Doosan Bobcat ’ s T7X compact track loader not only replaces the engine with an electric battery and motor , but it also eliminates the hydraulics , instead using an electrical drive system consisting of electric cylinders and drive motors . The company partnered with Green Machine Equipment and Moog Construction in creating the T7X .
Doosan Bobcat started experimenting with electric-powered machines about five years ago , said Joel Honeyman , vice president of global innovation . “ We wanted to take some new technologies from other industries and do some unique things with the platform ,” he said .
“ With an all-electric system , it ’ s power on demand , only using the energy you need for the task at hand ,” said Dave Grabau , key account manager , Moog Construction , a Doosan Bobcat partner on the T7X . “ You ’ re not running at wide open throttle or dumping hydraulic fluid over a relief valve and wasting that energy . The powertrain is not limited by emissions tiers , such as 55 kW ( 74 horsepower ).
Now you can get more work done in a 5-to-6-ton machine that has a usable power range of 100 to 150 horsepower ,” Grabau said .
Currently in production , the first T7Xs are being added to Sunbelt Rentals ’ fleet .
That brings us to the question of how best to charge electric machines .
4 NCP Magazine • October 2022