ProLogium and Rimac unveil battery pack mock-up concept, with on-road testing targeted for late 2028

An OEM powertrain engineer who stops at the ProLogium and Rimac display at the 2026 Paris Motor Show ^[3] will be looking at a mock-up. The two companies describe it as a concept ^[1], and their own plan puts lab, in-vehicle and on-road testing still ahead of it ^[3].

What the pitch says about cell-to-pack is that dropping the individual casings saves space and weight ^[4]. What the companies say themselves is narrower. According to Interesting Engineering's account of the statement, they cautioned that combining high-energy cells does not automatically produce a lighter or more compact vehicle battery system, and that pack design, cooling, mechanical integration and safety decide which advantages reach the vehicle ^[10].

Daniel Kišić, Principal Product Architect at Rimac Technology, put the gains in conditional terms. "Once validated at vehicle level, the solution is expected to deliver significant weight savings, improving driving efficiency and extending range," he said ^[14]. Interesting Engineering's report does not include a weight, range or cost figure ^[11].

Vincent Yang, ProLogium's founder and CEO, described the next stage. "We are preparing to move into the development and production of a functional battery, progressing toward a full-scale battery pack and subsequent vehicle integration validation," he said ^[15].

From the September 2025 MOU to the planned start of road testing is about three years ^[13].

We think a buyer should track this and not design around it. Tracking costs an engineer's attention at CES in January 2027 ^[6]. Designing in costs a program built on weight and range numbers nobody has measured.

A two-part test sorts any battery claim the same way. The first part is whether the number has been measured on hardware that someone outside the maker can inspect. The second is whether your program needs the number before the road-test date. Measured and needed: evaluate it for sourcing. Measured and not needed: file it. Unmeasured and needed: keep a second cell supplier open. Unmeasured and not needed: wait for the next milestone.

ProLogium's weight and range claims sit in the unmeasured row today ^[3]. A segment shown at CES moves them only if it arrives with test data.