ALL- ELECTRIC
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MOFFETT
The quiet
revolution
It’s ultra-quiet, has 0% emissions and will change operators’ views of truck-mounted forklifts. Meet the all-electric Moffett
Words and images: Brian Weatherley The truck-mounted fork-lift (TMFL) market is on the brink of a quiet revolution. And behind it is the company that’s become the by-word for TMFLs – Moffett. Its first appearance will be a sneak preview at the CV Show (ahead of an official launch at the IAA in September), but CM has had an exclusive early look at Moffett’s prototype all-electric TMFL. This not only takes the Dundalk-based company into previously untapped markets but, equally important, also provides it with an intriguing Plan B to the ever-tightening Tier-4 emission regulations for construction/non-highway diesel-powered vehicles (including TMFLs) over 19kW/25hp, due in 2016/17.
The E-Moffett, based on the company’s diesel-engined M2 and M4 models, offers ultra-low noise and emissionfree opportunities to companies faced with increasing restrictions on urban deliveries. And because the switch to electric power has been achieved without a major deterioration in load-carrying capacity or operating cycles, Moffett reckons it’s not just cleaner and greener, but ultimately cheaper to run too.
At the heart of its electric TMFL is a 6kW brushless AC traction motor that drives the single rear wheel on the 1,500kg capacity M2 model and 2,000kg capacity M4. A secondary 800W motor provides power for its steer-by-wire steering system, while a third 10kW motor drives the 12cc hydraulic gear-pump for the lifting mast and forks. Having taken the decision to develop an all-electric TMFL some three years ago, Moffett ultimately rejected lead-acid batteries as the motive force as too cumbersome and heavy. Instead, production models will be powered by a 15-cell lithium-ion phosphate battery pack, which Moffett R&D manager Barry McGrane says is not only half the size of the equivalent lead-acid batteries, but a quarter of their weight.
With the electric motor, battery pack and management system occupying the same envelope as a diesel-engine drivetrain, the electric Moffett’s weight is almost identical to a diesel-powered model. The company is quoting a tare of 1,591kg for the 130Ah battery pack M2, and 1,679kg for the 180Ah pack M4. As well as being lighter, the lithiumion cells also offer double the total life of lead acid batteries. “They’re capable of well over 2,000 [charging] cycles so typically they should last the lifetime of the machine,” says McGrane.
With a diesel-powered TMFL typically working a one-and-a-half hour daily dutycycle, the electric Moffett’s lithium-ion battery pack provides enough juice for two-and-a-half hours. McGrane explains: “Driving it up slopes and ramps absorbs power – so that’s what the ‘reserve’ is for.” Should operators need more energy they can specify greater capacity batteries.
Trickle-charging
A full deep-charge cycle for the electric Moffett takes six hours, although power can be recouped during the working day by its regenerative braking function, standard on both models.
The company is already investigating trickle-charging the battery pack while the electric TMFL is attached to a truck or trailer, via the normal electrical umbilical chord used to power brake and tail-lights. “We’re looking at some form of ‘opportunity charging’, through the existing 24V system,” says McGrane. “As most machines spend around 90% of their time mated to the truck it makes sense to use that time for some form of charging.” Both models will have optional ground-mounting, so they can be loaded and unloaded onto a vehicle without the operator having to remain in the driving seat.
An easy-to-read digital display advises how much power is left in the battery, as well as real-time power usage. When battery power is down to 10%, the driver is alerted and the system automatically switches to a ‘limphome’ mode where speed is reduced, but not stopped.
How quiet is the electric TMFL? Moffett is putting it through the Dutch PIEK standard which will see it certified at below 60dB(A). However, the most attractive part of the E-Moffett will arguably be its ‘infrastructure’: a single 240V power lead. By fitting all the electrical charging equipment on the fork-lift itself, the only extra piece of kit an operator will need to repower the electric Moffett is a 240-volt socket in the workshop. n