How to Buy a Battery-Electric, Twin-Drum Vibratory Compactor + Brand Summaries
Battery electric is a good choice for compact compaction, which includes twin-drum vibratory compactors used in asphalt. We’ll explore why this is true in general before looking at insights from three leading manufacturers of battery electric compaction machines.
Battery electric is good for machines up to 5 tons. These smaller machines are more likely to return to the shop each evening, simplifying charging. Larger machines start to have weight, run-time and charge-time issues with battery electric power, issues that keep those machines operating with internal combustion engines for now. The manufacturers we contacted for this article are all based in Europe, and in compact compaction, there are high similarity between the E.U. and North America. Machine design and customer preferences begin to diverge as you move into larger models. Run-time is usually said to be adequate for an eight-hour shift of intermittent use or three to five hours of steady use.
Service life is commonly quoted as 10 years or 3,000 to 3,500 charge cycles. Fifty-two five-day work weeks give 260 working days per year, times 10 years is 2,600 working days, so the charge cycles are well in line with that utilization rate even when adjusted for holidays and overtime. It is estimated that 80 percent of battery life remains at that point, so the late part of the life cycle isn’t spent with a derelict machine without a reasonable duty cycle. Seasonality comes into play; fewer asphalt jobs are done in cold weather, so working days are reduced in higher altitudes and latitudes. Reduced hours in cold weather also improve battery performance. Battery life is heavily influenced by depletion levels and charge rates, with deeper drawdown and faster charging reducing battery life.
Subsidies and other incentives can reduce upfront costs for battery-electric compactors and help narrow the significant cost increase from internal combustion to battery electric. However, because battery-electric compaction is relatively new and remains a small part of the market, some cost information is not yet available. It’s assumed the depreciation curve of these machines will be comparable to their diesel counterparts, but we don’t know yet. Rapid advances in battery technology complicate recycling and re-use strategies for current batteries, and as new battery technology brings along new advantages, residual value of current models will likely be negatively affected. Increases in fossil fuel prices will increase demand for battery-electric machines, possibly resulting in inventory shortages and certainly shifting the cost advantage in favor of electric.
Availability and especially cost of replacement batteries remain issues that complicate re-powering high-hour compactors. Maintenance costs and complexity are much lower with battery-electric machines. Models equipped with hydraulics have the usual fluid and filter requirements, and all models will still have daily checks, but those daily checks are fewer and faster with battery electric.
Staying Cool
Compact battery-electric compactors use 48V batteries. This is adequate for their needs, but it also simplifies cooling considerations. Higher voltage batteries often need special cooling packages for both use and charging, and that creates challenges for space, charging locations and machine design. Asphalt compactors are often used in direct sun on hot days with heat radiating off the mat, a combination that could overwhelm the cooling capacity of higher-voltage systems.
Bomag: Clever Design, Robust Construction
John Gravatt, product marketing manager, asphalt compaction, Bomag Americas, says the BW 100 AD e-5 and Bomag BW 120 AD e-5 tandem rollers with electric drive accept AC chargers with a Type 2 connector or a DC fast charger. The machines use a bank of four 48V lithium-ion batteries so batteries can be replaced independently if replacement is required.
The e-5 models use electro-hydrostatic travel and vibration drives. Gravatt says manufacturers take multiple approaches to machine design. Some use electric over hydraulic, with electric motors powering the hydraulics. Some replace hydraulics with electric motors for some functions, such as vibratory motors on the drums, and some go fully electric for drive and vibratory systems. These are important distinctions, and each has advantages and disadvantages, but it’s far more important to look at the overall performance of the machine and the dealership.
Options include an Economizer with asphalt temperature display, telematics, Joblink measuring technology and a Joblink Bluetooth adapter, indicator and hazard lights and rotary beacon.
“While battery-electric rollers are not a fit for all customers,” says Gravatt, “they can certainly be effectively utilized where the proper conditions exist, like access to charging infrastructure.”
Dynapac: Charge and Take Charge
Erik Booth, product manager, asphalt rollers, Dynapac, says serial production of the Z.ERA models began in 2024. In European fashion, the model line is referred to as “zed-era.” There are two models now available, the CC900 e and CC1000 e, both with size, weight and performance comparable to their internal combustion engine counterparts. Dynapac has both gasoline and diesel power models.
Charging with 120V takes around six hours. The fast charger already in use in Europe is being modified for use in the U.S. market. Dynapac is working on an adapter to allow charging at charging stations for electric vehicles. Other options include a gen set for remote charging. “These machines are fairly forgiving of input current and don’t need especially clean power, such as pure sine wave output from high-end generators.”
Right now, the price differential between battery and diesel machines is two or two and a half times higher for electric. They will remain niche machines until the price differential comes down, and that depends heavily on battery costs. When will that happen? “That’s hard to say. Battery technology is advancing quickly, but there are no hard timelines in place,” says Booth. Both Z.ERA models use 48V lithium-ion batteries. Is battery electric an endpoint for compact compactor development?
“That’s hard to say,” says Booth again. “It depends on the next energy source, whether that’s hydrogen or something else.” For now, battery electric is an excellent choice for customers who see benefits from its unique design advantages.
Volvo: Paving the Way for Zero Emissions
The DD25 Electric is Volvo Construction Equipment’s first battery machine specifically for paving applications. They also have four electric excavators and two electric compact wheel loaders. The DD25 Electric models use 48V NMC (nickel, manganese, cobalt) batteries. Justin Zupanc, head of electromobility and autonomous solutions, road products, Volvo, advises customers rethink usage in getting the most from their battery machines.
“With battery electric,” he says, “it’s still utilization rate, but with an emphasis on running hours, not idling hours.”
He also offers advice for charging. “The focus in the media and among customers is overnight charging versus fast charging. I advise thinking of opportunity charging, which is battery top-offs when the machine is idle, such as when waiting on the next truckload of asphalt.”
He also says the comparison between the E.U. and North American market on small compactors is valid, but that the electric market has been underserved in North America while being well addressed in Europe. He hesitates to call North America a niche market for electric compactors because of the untapped demand and predicts there will be steady growth, “but electric will not overtake internal combustion in the immediate future”
Richard Ries is a freelance writer for Compact Equipment.
Hamm Launches Battery-Electric Driven Tandem Rollers
Hamm is now offering completely battery-electric driven tandem rollers for the North American market. Since April the new machines complement the HD CompactLine Series. Some models are equipped with oscillation drums, including the world’s first e-combination rollers with oscillation. They are not only compact and emissions-free but also quiet. With eight electric rollers in the compact class, Hamm’s launch represents a milestone for the compaction industry. The HD 10e model and the HD 12e model boast the same compaction power as their combustion engine counterparts but produce zero local emissions. The e-rollers are operated in almost the same way as the other models in the HD CompactLine Series. A 48V lithium-ion battery with 23.4-kWh capacity provides the energy for driving, steering and dynamic compaction. Charging from 0 to 100 percent takes approximately four hours on 220V. For more info, visit wirtgen-group.com/en-us/company/hamm.
