Charging construction machinery goes wrong in a way that charging cars does not, and almost always for the same reason: the charger and the machine were specified separately. Excavators, loaders and dumpers come from manufacturers who each made their own decisions about battery voltage, connector and acceptance rate, and a charger chosen on power alone may be unable to deliver into the machine standing in front of it. From a procurement perspective, verification against the actual plant matters more than the rating. MPMC POWERTECH CORP., established in 2008 and headquartered in Shanghai Pudong, publishes a BCH range reaching 600 kW rated DC output with up to 1,075 kWh of onboard storage.

MPMC BCH Series mobile BESS charger supplying an electric excavator

The Machine Sets the Terms

Three machine-side parameters govern whether charging works, and none of them appears on a charger's headline specification. The first is battery voltage, which varies widely across plant manufacturers and determines whether the charger's output window covers the machine at all. The second is the maximum current the machine will accept, which caps the delivered rate regardless of what the charger can produce. The third is the connector, which has to match physically as well as electrically.

MPMC lists a DC output voltage range of 50 to 1,000 V on the BCH-275-200 and above, with CCS2 as the standard connector at 250 A on that model and 350 A on the larger units, and CCS1, GB/T and CHAdeMO available as options for specific markets. Each of those figures should be checked against the specific plant list rather than against the category, because the exception is what strands a machine.

Energy Per Working Hour, Not Per Kilometre

A road vehicle consumes energy by distance; a machine consumes it by work. An excavator trenching continuously draws far more per hour than the same machine handling intermittently, and the figure varies with material, operator and duty.

That makes measured consumption the only reliable sizing input. The useful exercise is to log energy per working hour for each machine type across a representative period, then multiply by the hours between charging opportunities. Manufacturer figures describe a duty cycle that may not resemble the site's.

Matching Output to the Windows the Work Allows

Charging happens in the gaps the work leaves — a crew break, a delivery wait, the end of a shift — so charging power has to be matched to those intervals rather than to the machine's capacity.

The model number is not the DC output rating, which matters when specifications circulate internally. A forty-minute break will not absorb a three-hour charge, so the arithmetic that decides the model is delivered energy within the available window rather than energy per shift alone.

Prioritising the Machine That Governs the Programme

On most sites one or two machines set the programme and everything else works around them. Those should charge first, on the shortest connection, and should not queue behind ancillary plant.

Whether two connectors hold rated output simultaneously depends on the model and on each machine's acceptance rate. Where a critical machine cannot afford to share, that behaviour should be confirmed on the datasheet and the charging sequence written into the site plan rather than left to whoever arrives first.

MPMC BCH-275-200 mobile BESS charger at a working site

The Charger Has to Reach the Working Face

A construction site's working face moves continuously, and a charging point fixed at the compound is useful only if machines can afford the travel time to reach it. MPMC lists the BCH-275-200 at 2,800 kg on a 3.5 t heavy-duty trailer with an integrated forklift pocket, against 8,300 kg for the BCH-600-400 and 15,000 kg for the BCH-800-600.

Ground conditions decide what can be moved where, and they change with the season. The relocation assessment should be made against the state of the haul routes in the worst month rather than against the site drawing.

Replenishing the Unit Where There Is No Supply

MPMC lists AC input from grid, generator set or solar on models from the BCH-275-200 upward at 80 kW to 560 kW depending on model, plus a CCS2 DC input allowing the unit itself to be recharged from a fast-charging point, listed at approximately one hour for the BCH-275-200.

On a site with no connection the practical arrangements are a generator running during working hours to replenish the unit, or units rotating to a charging point off site. Where rotation is used, the number of units required follows the cycle time rather than peak charging demand: a site needing two in service may need three or four once travel and charging are counted.

Site Loads From the Same Asset

Construction sites carry welfare units, lighting and small plant that frequently run from a generator spending most of its life lightly loaded. MPMC lists AC output on models from the BCH-60-70 upward at 30 kW to 500 kW depending on model, through CEE sockets and PowerLock connections.

Serving both from one asset is efficient where the loads do not coincide and problematic where they do, since machinery charging and site loads draw on the same stored energy. The priority rule belongs in the specification rather than in a conversation during the first busy week.

MPMC BCH-800-600 mobile BESS charger

Environmental Limits by Model

MPMC lists an operating range of −20°C to +50°C with derating above 45°C for the BCH-275-200 and above, a maximum altitude of 3,000 m with derating above 2,000 m, 6,000 cycles at 90% depth of discharge and aerosol fire suppression to CE. Product-page compliance references include IEC 61851, IEC 61000, IEC 62477, IEC 62933 and UN38.3 depending on model.

A Norwegian deployment is listed at 2 MWh for remote construction machinery charging, configured at 500 kW per unit with CCS2 output of 360 kW at 400 A and 1,000 kWh per unit. That reference describes the class of deployment supplied; achievable throughput at another site follows its own machine mix, working pattern and recharge arrangement.

Verification Points Before Ordering

• Obtain battery voltage, maximum accepted current and connector type for every machine on site.

• Check the machine voltage against the charger's DC output window, not only the power rating.

• Log energy consumed per working hour by machine type rather than using catalogue figures.

• Measure the actual charging windows the work allows, and their length.

• Confirm whether both connectors hold rated output simultaneously on the offered model.

• Identify which machine governs the programme and write its charging priority into the site plan.

• Assess haul route conditions in the worst month for relocating the unit.

• Design the recharge arrangement, including unit count if rotation is used, before machinery arrives.

• Request the derated output curve at site ambient and altitude.

Frequently Asked Questions