CATL has unveiled a rather intriguing range extender for electric trucks. The architecture doesn’t use a combustion engine but rather a dual-battery system that pairs a large swappable main pack with a small, permanently installed reserve battery.
On paper, it is a neat fix for range anxiety, but almost everything that makes it work exists only in China, at least for now.
According to CATL, drivers of battery-swapping electric trucks often return to stations with roughly a third of their battery capacity unused. They don’t want to risk running out of power before reaching their destination.
For fleet operators leasing those batteries, it is a costly inefficiency: a third of the capacity is carried over thousands of kilometers but never fully utilized.
“1+x”-architecture
CATL’s solution is deceptively simple. Add a small, permanently installed battery so the larger, swappable one can be drained almost completely. The result is an intriguing piece of engineering. A 77 kWh backup battery could make approximately 128 kWh of previously avoided capacity available from the main pack.
The system follows what CATL calls a “1+X” architecture. The “1” is a standardized chassis-mounted battery with 432 or 513 kWh, depending on the wheelbase.
This is the pack that operators lease rather than buy and which their drivers can exchange at CATL’s QIJI swapping stations in about five minutes. The “X” is a 77-kWh pack mounted behind the cab. This stays with the truck and is configurable for cold weather, energy density, or power output.
Under the proposed arrangement, the main swappable battery is leased through the QIJI ecosystem, reducing the vehicle’s upfront purchase cost. The smaller backup battery remains attached to the truck as an asset.
Technology meets psychology
CATL says the backup allows operators to increase the main battery’s depth of discharge from approximately 70% to more than 95%. When the larger pack’s charge drops to 5%, the system can switch power delivery to the smaller battery within milliseconds.
So, the presence of the smaller battery gives drivers the confidence to use more of what was already available in the main pack. It’s technology meeting psychology, but it remains clever. It is a way of extracting more practical value from existing capacity.
The wider economic promise is even more ambitious: according to CATL, L savings exceed 460,000 yuan, roughly €61,590, over three years compared with diesel operation.
CATL is tapping into a booming segment. New-energy heavy trucks accounted for approximately 50% of China’s domestic heavy-duty truck registrations last September, compared with around 29% a year earlier. T
hat category includes more than purely battery-electric vehicles, but the shift illustrates how quickly alternative drivetrains are gaining ground.
Europe taps into swapping too.
The technology’s greatest strength is also its central vulnerability. A swappable battery is valuable only if the operator can reliably find a compatible station along its route. CATL plans to expand its QIJI network to 900 heavy-truck swapping stations by the end of 2026, followed by 2,000 in 2027 and eventually 10,000 nationwide.
There are engineering compromises, too. The 77 kWh reserve adds permanent weight, cost,t and another component to maintain. CATL’s announcement does not establish how those trade-offs compare with the gains under different payloads and operating conditions.
Currently, European manufacturers are largely betting on keeping batteries in vehicles and building megawatt-charging infrastructure around them. But that might change. Last summer, CATL and Britain’s Octopus Energy announced Swaptopus, a joint venture intended to bring heavy-truck battery swapping to Europe.
The partners plan their first UK hubs for 2027 and envisage more than 30 large European hubs by 2035. Germany’s EHaul is also developing truck-swapping infrastructure.
