Fast-charging EV packs, large ESS containers and high-power modules all need tighter thermal control, yet many teams are still wrestling with “one-off” tube layouts that are hard to validate and harder to scale. That’s the backdrop for XD THERMAL’s decision to industrialize serpentine tube production.
If you are asking whether this move actually matters for your next battery pack or ESS project, the easiest way to answer is to walk through the questions most customers already ask.
From the outside, serpentine tubes just look like neatly bent aluminum following cylindrical cells. From the inside of the project, they are the part that decides whether your high-rate pack stays inside its temperature window or slowly cooks itself at every fast charge.
In high C-rate cylindrical packs, heat builds up quickly at the cell sidewall during charging and discharging. Side-cooling serpentine tubes route coolant in close contact with these sidewalls, increasing effective heat transfer area compared with bottom plates alone. This helps reduce peak temperature and temperature spread between cells, supporting longer life and safer fast charging
The industry trend behind this is straightforward: cylindrical cell-to-pack designs are being pushed to higher currents and faster charging, which increases local heat flux and makes conventional air or bottom-only cooling less effective. At the same time, OEMs are tightening their internal limits on ΔT across the pack to protect cycle life and warranty exposure. Side-cooling serpentine tubes are one way to move more coolant surface area closer to the hottest part of the cell without completely redesigning the mechanical architecture. XD THERMAL’s side-cooling concept follows this logic, placing tubes along the cell sidewall and matching the tube pitch to the cell layout so that cooling performance can be predicted and compared across different module and pack designs.
Many teams have tried to design their own serpentine tubes for a battery pack and even run simulations on them, only to find at the production stage that the design is not really manufacturable: it may fully meet the standards as a prototype, but is almost impossible to keep stable and consistent in mass production.
The comparison shows that total area-to-volume ratio drops from 25.3 % for a 18650 cell to 21.9 % for a 21700 and just 11.2 % for a 4680 cell. The side area-to-volume ratio, which governs radial heat dissipation, falls from 22.22 % (18650) to 8.7 % (4680). In other words, a 4680 cell has roughly half the surface area per unit volume of a 18650; the bigger cell therefore generates more heat per unit surface when charged or discharged at similar C rates
Typical issues that show up at this stage include:
● Tube paths that work in CAD, but require bending radii or angles that standard machines cannot repeat reliably;
● Geometries that pass simulation for one “ideal” shape, but lose cooling performance once real-world tolerances and spring-back are included;
● Designs that are weldable or brazeable in the lab, but very sensitive to fixture, cleanliness or operator skill on a line;
● Good contact between tube and cells in samples, but large variation once hundreds or thousands of parts are produced;
● Inspection and leak-testing concepts that are clear for a few pieces, but not practical for high-volume, automated testing
As EV and ESS programs scale up, these gaps between “simulated design” and “industrialized product” become more visible. Battery thermal management is expected to more than double in market size toward 2030, driven by higher safety and warranty expectations. That means OEMs are less willing to rely on hand-bent or one-off tube designs for a safety-critical thermal path. Instead, they increasingly ask for tube structures that have been engineered together with bending, joining and testing processes, so the same geometry that works in CAE and in a small batch can also be produced repeatably across an entire vehicle or ESS platform.
When you look at your roadmap – different pack sizes, different voltages, maybe multiple cell formats – the question becomes: do you really want to start from zero on the cooling layout every single time? A platform approach is one way to stop re-solving the same problem.
| Dimension | One-off serpentine design | Serpentine-tube platform at XD THERMAL |
|---|---|---|
| Starting point | New layout for each project | Family of side-cool modules and packs |
| Geometry | Custom bend patterns and pitches | Tube pitch matched to cylindrical cell spacing |
| Performance behavior | Verified only project by project | Based on validated flow paths and internal rules |
| Integration | Custom manifolds and brackets each time | Shared manifold and bracket concepts across designs |
| Scalability | Capacity depends on ad-hoc bending setups | Automated, high-capacity tube manufacturing |
XD THERMAL’s recent platform announcement describes a family of side-cooled modules and packs built around robust tube structures and standardized QA methods. The cooling tubes are pitched to align with cylindrical cell layouts and can be combined with different manifolds and brackets while the internal design rules keep flow distribution and heat-transfer performance predictable from prototype to mass production. For customers, this means that each new project can often reuse an existing tube pattern or a small variation of it; much of the thermal, pressure-drop and manufacturability behavior is already known, which reduces design iterations, test loops and SOP risk.
At first glance, building full in-house capability for extrusion, bending, brazing and testing serpentine tubes may look like a heavy investment. For XD THERMAL, however, it is a straightforward extension of its core business: designing and producing battery liquid-cooling components with tight control over geometry, process and quality from day one.
In practice, industrial-scale in-house production of serpentine tubes enables:
XD THERMAL operates plants totaling more than 100,000 m², with annual capacity above 1,489,200 units, and includes its own extrusion line, machining centers and coating line. This setup allows the company to manage everything from raw profile extrusion, through tube forming and joining, to finishing and testing under one quality system certified to IATF 16949. In practice, that means serpentine tube designs can be checked directly against machine capability, welding windows and cleaning limits before a drawing is ever frozen. It also means that when an OEM needs to ramp a platform across regions, XD THERMAL can back that with real, audited production capacity instead of a network of small job shops.
You might also be asking a more strategic question: “Is this just XD THERMAL optimizing its own cost structure, or is there a broader trend in thermal hardware behind it?”
EV thermal systems, battery thermal management and data-center liquid cooling are all growing faster than their host markets. EV thermal systems alone are projected to rise from about USD 5.6 billion in 2024 to around USD 14.4 billion by 2030, while battery thermal management systems are expected to more than double in value over a similar period. Data-center liquid cooling could reach USD 15–20 billion by 2030 as AI drives higher rack densities.
In parallel, technology leaders in computing are pushing cooling hardware to new levels, such as micro-fluidic channels etched directly into chips that can reduce peak temperature rise by around 65% compared with conventional cold plates. This raises expectations across all thermal applications: better heat-flux handling, tighter control of temperature gradients and higher reliability over long service lives. Against that backdrop, industrialized serpentine tube production is not a niche idea; it is part of a broader shift where critical thermal components move from “cheap bent metal” to engineered, platform-grade hardware with dedicated capacity and documented performance. XD THERMAL’s investment is one example of this shift in the cylindrical-cell segment.
At the end of the day, you still have deliverables and deadlines. So the most practical question is: “If I use XD THERMAL’s industrial serpentine tubes, what changes in my project life?”
Typical impacts for OEM and Tier-1 customers include:
XD THERMAL positions itself as a full-service supplier rather than a parts-only vendor: its offering covers thermal design support, liquid-cooling layout co-design, prototype samples, validation samples and mass production, all backed by in-house testing such as coolant temperature cycling, corrosion, flow resistance, leak and burst tests. The company also reports over 300 successful battery-cooling cases across EV and ESS applications worldwide, indicating that serpentine tubes are being deployed in a variety of real projects rather than just demo rigs. For a project team, this translates into one fewer major uncertainty: the same partner that helps define the serpentine tube structure is also responsible for making it at scale, under a known process and quality regime.
XD THERMAL’s decision to industrialize serpentine tube production is not simply an internal manufacturing tweak; it is a response to tighter thermal requirements, platform-driven pack roadmaps and the need for reliable capacity in a fast-growing market. For customers, it offers a way to treat side-cooling hardware as a stable platform asset—designed, validated and manufactured as one coherent system—rather than as a series of one-off bent tubes.
[1]: https://www.xdthermal.com/battery-cooling-tube.html
[2]: https://www.marketsandmarkets.com/Market-Reports/automotive-battery-thermal-management-system-market-184479896.html
[3]: https://www.strategicmarketresearch.com/market-report/electric-vehicle-thermal-system-market
[4]: https://www.livescience.com/technology/computing/microsoft-unveils-new-liquid-cooled-computer-chips-they-could-prevent-ai-data-centers-from-massively-overheating
