The way cells are arranged and cooled in a high-voltage battery pack has a major impact on the usable range of an electric vehicle. Factors like energy density, heat dissipation, and voltage management all come into play. Which concepts do you think are most effective for maximizing range without shortening battery life? Are there proven approaches you believe should be considered in future models?
How does the architecture of high-voltage batteries affect the range of electric vehicles?
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The arrangement of cells is the first lever to increase usable range. In modern modules, manufacturers are increasingly turning to a 3D pack design, where cells are not only arranged in a single flat layer but in multiple stacked levels. This increases the energy density within the pack, as more cells fit into each cubic meter of space, while also shortening the electrical path length, which reduces internal resistance. Combined with a modular design using cylindrical (e.g., 2170) and prismatic cells, the advantages of both types can be leveraged: the high mechanical stability of cylindrical cells and the flexible shape of prismatic cells for tight packaging constraints.
An effective cooling system is just as critical as cell architecture. Liquid cooling with integrated cooling channels directly in the cell housing ensures uniform heat dissipation and prevents hot spots that accelerate degradation. Additionally, phase-change materials (PCM) can be placed between cells to buffer short-term temperature spikes without requiring a permanent increase in pump performance. Active balancing algorithms, controlled via an advanced Battery Management System (BMS), compensate for voltage deviations in real time and reduce the load on individual cells.
For future models, these two concepts—high-density 3D pack architecture and integrated liquid/PCM cooling—should be combined with precise thermal prediction through AI-driven modeling. This maximizes range while preserving cell lifespan by keeping temperature profiles within the optimal operating range. These approaches have already led to visible improvements in current premium EVs and provide a solid foundation for the next generation of electric vehicles.
I made a modification to my 2018 BMW i3 that really drove home the importance of cell architecture and cooling. The car originally came with a linear arrangement of prismatic cells and an air-cooled system. After a few hundred kilometers, I noticed the range fluctuated wildly in city driving and dropped significantly on longer highway trips, mainly because the cells in the middle of the pack overheated quickly.
To fix this, I upgraded the battery module to a modular 3D stack architecture, where the cells are arranged in small blocks and cooled by a liquid glycol-water mixture circulation system. The improved heat dissipation lowers internal resistance during high power draws, keeping voltage stable longer and effectively boosting energy density by about 7%. In practice, this gave me an extra 20 km of range per charge without noticeably accelerating battery degradation.
From my experience, it's clear that a compact, volumetrically efficient cell arrangement combined with an active liquid cooling system are the best ways to maximize usable range while also preserving battery lifespan. Many manufacturers are already adopting these concepts—for example, the new generation of Mercedes EQ models uses a modular cell structure with integrated coolant, which I think is a future-proof design. For upcoming models, it might also be worth considering intelligent voltage balancing that dynamically optimizes cells based on temperature and state of charge.
The most effective method for increasing range is a modular cell arrangement, where individual cells are interleaved in a 3D pack with short current paths—similar to the high-performance batteries in the Renault Formula 1 power unit, where energy density is extremely high thanks to compact pack geometry. This compact arrangement reduces internal resistance, minimizing energy loss as heat and thereby increasing both usable capacity and lifespan.
In contrast, some mass-market EV manufacturers still rely on flat, large-surface pack layouts, which are easier to manufacture but suffer from higher voltage drops and poorer cooling surfaces. By combining the modular 3D structure with an active liquid cooling system—a concept already tested in Renault’s rally program for handling temperature fluctuations on dusty tracks—heat dissipation can be significantly improved without adding excessive weight to the battery thermal management system. This combination of dense cell packing and targeted liquid cooling seems to me the most promising approach to maximize range while maintaining cycle durability.
A modular arrangement of flat prismatic cells with active liquid cooling, as used in the Porsche Taycan for example, delivers high energy density and stable temperatures, thereby increasing range without compromising battery lifespan. Additionally, an advanced BMS balancing system combined with 12‑V power management—proven approaches that should become more widespread in future models.