Megawatt Charging System: how electric truck charging scales

A driver on a European long-haul run does not get to choose when to stop. Regulation (EC) No 561/2006 requires a break of at least 45 minutes after four and a half hours at the wheel, and a daily rest of nine to eleven hours after nine or ten hours of driving. Those numbers are the frame every battery-electric truck has to fit inside, and they are the whole reason megawatt charging exists. The question was never whether a big truck could be charged quickly. It was whether it could be charged inside a break the driver was going to take anyway.

What MCS actually is

The Megawatt Charging System is a connector standard developed by the CharIN industry body for vehicles whose batteries are too large for car charging hardware to serve. Its design ceiling is 1,250 volts DC and 3,000 amps, which is 3.75 MW on paper, though nothing on the road is close to using that. The interface specification has been published as IEC TS 63379; the charger-side requirements, IEC 61851-23-3, are still in development, which is why manufacturers’ quoted charging times still carry the word “simulation” in the footnote.

Two differences from CCS matter more than the headline rating. The cable and connector are liquid-cooled, because 3,000 amps through an air-cooled cable is not something a driver could lift. And the communication layer is purpose-built rather than inherited from passenger cars, which matters less for speed than for whether a truck from one maker negotiates cleanly with a charger from another. That is the failure mode that actually strands vehicles.

The arithmetic that forced it

Take a Mercedes-Benz eActros 600: three LFP packs, 621 kWh installed, a stated range of up to 500 km, and CCS2 charging at up to 400 kW. Refilling the 20-to-80% window, where fast charging is genuinely fast, means moving roughly 370 kWh. At 350 to 400 kW that is an hour before you account for taper. Mercedes puts the same job at around 30 minutes at 1,000 kW.

The gap between “an hour” and “half an hour” is the gap between a charge that eats the working day and a charge that disappears into a break the tachograph was going to force anyway. Nothing else about MCS matters as much as that.

Volvo publishes the comparison inside a single vehicle, which is more useful still. On the FH Aero Electric, 20 to 80% takes about 50 minutes on MCS at 700 kW and about 85 minutes on CCS at 350 kW. Same truck, same battery, same route: the charger decides whether the shift works.

Note the 700 kW. Volvo is not using the standard’s ceiling, and neither is anyone else. Scania, which offers MCS on its battery-electric trucks from mid-2026, describes MCS as roughly ten times a CCS2 rate of 350 to 400 kW and quotes 20 to 80% in under 30 minutes. “MCS-capable” is not a single number. Read the inlet rating on the vehicle you are actually buying.

Which trucks genuinely need it

This is where fleets overspecify. Volvo’s next-generation FH, FM and FMX Electric, the regional and construction range with up to 470 km, are CCS-only at 350 kW and take about 65 minutes for 20 to 80%. That is not an omission. A truck that comes home to a yard every night charges overnight, on cheap power, on hardware costing a fraction of a megawatt charger.

The test is duty cycle, not battery size. If the vehicle sleeps at your depot, overnight charging covers it and public fast charging is contingency. If it runs the kind of work a diesel Volvo FH or Mercedes-Benz Actros L does today — high annual mileage, nights away, breaks taken at motorway services — then charging speed is the binding constraint and MCS is the answer to it.

What the law requires, and what it does not

AFIR, Regulation (EU) 2023/1804, is the instrument putting truck chargers on European motorways. It requires publicly accessible recharging pools dedicated to heavy-duty vehicles with a minimum aggregated output of 1,400 kW, including at least two individual recharging points of at least 350 kW each, no more than 120 km apart, with the TEN-T core road network covered by the end of 2025 and half the comprehensive network by the end of 2027.

Read the individual figure again: 350 kW. AFIR does not mandate megawatt charging anywhere. It sets a floor on site capacity and a floor on point power that lands a third of the way to a megawatt. A member state can be fully compliant along a corridor on which no MCS truck can charge at MCS speed.

That is a sequencing problem rather than an oversight — the regulation was drafted before the standard was finished — but it has a planning consequence. Compliance maps tell you where trucks can charge. They do not tell you where an MCS truck can charge fast. Only the charging operators’ own site lists do that.

Where the constraint really sits

Milence, the joint venture Daimler Truck, TRATON GROUP and Volvo Group set up precisely because none of them could wait for someone else to build the network, runs MCS hardware rated to about 1,440 kW and has demonstrated 1.1 MW into an eActros 600. It plans MCS points along freight corridors at roughly 100 km spacing, partly to spread grid load rather than concentrate it.

That is the real bottleneck. A multi-bay megawatt site is a several-megawatt grid connection, and grid connections are queued, permitted and paid for on timescales that have nothing to do with truck production. Operators buffer with on-site battery storage and load management for exactly this reason.

Daimler Truck’s own framing is instructive. When it sent an eActros 600 on a 2,400 km run from Wörth am Rhein to Linköping in Sweden in January 2026, it said plainly that only a few public MCS locations were available in Europe, and described the exercise as checking whether vehicles and chargers from different manufacturers work together under real conditions, winter included. Interoperability is still being proven on the road.

Three questions before you sign

What is the truck’s inlet rated at? 700 kW and 1,000 kW are both called MCS and produce charging times twenty minutes apart on the same battery.

Where does the vehicle sleep? If the answer is your own yard, buy depot charging and treat public MCS as insurance. Almost all of the operating-cost advantage of electric haulage comes from cheap overnight energy, not from fast public charging, which is the most expensive electricity a fleet buys.

Which corridors does it actually run? Not which are AFIR-compliant — which have MCS hardware installed today, from which operator, and whether a bay can be booked. A megawatt-capable truck on a corridor without megawatt chargers is a 350 kW truck with an expensive socket.

For a fleet still running a diesel Scania S-series on international work, none of this is urgent this year. The fleet CO2 targets that make it urgent are already in law, and the trucks that answer them are being ordered now.