Introduction: VDA 355 fixes the outer envelope of a battery module, and that envelope decides how modules sit, wire, and get serviced inside a Leaf pack.
Technicians sizing up a battery repair usually start in the same place: the tray. Before torque values or communication checks, the first question is whether the replacement module will physically sit where the old one sat, with enough room left for the busbar, the sensor harness, and a wrench. That is where VDA 355 dimensions earn their keep in the workshop. The 355 x 150 x 110 mm envelope published for the CATL 4S1P 177Ah NMC module is a mechanical statement first, and everything about module placement, enclosure space, and repair sequencing flows from it. This explainer walks through what those three numbers describe, how they shape the way modules drop into an original Leaf enclosure, and why the space around the terminals and sensors often decides whether a repair plan works.
What VDA 355 gives the aftermarket is a shared size language. Instead of each module being a one-off box, the format sets a common mechanical envelope that pack designers, tray fabricators, and repair shops can all reference. The three published figures describe the outside of the case: 355 mm along the long axis, 150 mm across the width, and 110 mm from the base to the top of the housing. Weight belongs in that same conversation, because a 12.5 kg module shapes how a technician lifts, supports, and seats it without stressing the tray or the cooling interface beneath it. The envelope also implies a layout inside the case. The terminal band sits on the top face, the sensor wiring exits in a predictable place, and the mounting surfaces run along the base and sides. When a workshop compares listings from several ev battery suppliers, the dimensional line is usually the fastest filter, because a module that misses the footprint by even a few millimeters will not line up with the original rails. Electric ratings matter for system design, but the mechanical numbers decide whether the module physically belongs in the pack at all.
Leaf packs are shallow and built around stacked, tightly packed modules, so the envelope works as a layout constraint rather than a nice-to-have. The 355 mm length typically runs along the long axis of the tray, the 150 mm width sets the pitch between neighbouring modules, and the 110 mm height sets how much vertical room is left for the lid, the cooling plate, and the compression hardware. Those three relationships define how many modules fit in a row, how far apart the mounting rails sit, and how much service access remains once the pack is closed.
Footprint decides the floor plan, height decides the ceiling. A technician measuring a Leaf tray is really checking whether the module base lands flat on the cooling surface, whether the case edges clear the tray walls, and whether the top of the housing leaves enough gap for the lid and the high-voltage cover to close without pinching anything. Because the format is fixed, row spacing becomes predictable and repeatable, which makes it far easier to plan a jig, mark mounting points, and check that a row of modules sits square before any busbar work begins.
A module can match the outer size exactly and still be awkward to install, because the working space above the case is what hands actually reach into. The terminal band, the sample harness exit, and the sensor connector positions all sit in that same 110 mm of vertical real estate, competing with the lid, the insulation barriers, and the tools used to torque the busbar. In practice, experienced technicians check terminal height and sensor lead routing before they check anything else, since a tight terminal footprint turns a straightforward swap into a slow, careful job.
A fixed module envelope makes repair work repeatable, and repeatable work is safer work. When the mechanical size is consistent from batch to batch, lift points, support blocks, and torque access stay the same, so a shop can write a procedure once and follow it on the next vehicle instead of improvising around a different case every time. It also makes documentation cleaner: the same envelope, the same service clearances, and the same reference points appear in the repair file, which matters when a second technician picks up the job or when a shop needs to explain the work to a customer. Standardized layout helps electrically as well. Because series connections, balance leads, and resistance monitoring tap points follow the module footprint rather than fighting it, the wiring path stays short and protected, which supports the balancing and monitoring practices described in automotive battery standards work. IEC TR 63213 covers performance and life testing terminology for automotive lithium batteries, which is useful when a shop wants to compare published module data on consistent terms, and IEEE references on series configuration and internal resistance monitoring explain why a tidy, predictable module layout is easier to monitor over time. Exact fitment still comes down to the enclosure, brackets, busbars, sensor wiring, and BMS integration in the specific pack, so the envelope is the starting point for planning rather than the whole plan.
VDA 355 is best understood as a mechanical agreement: 355 x 150 x 110 mm tells a repair technician how much floor space, height, and service clearance a module will claim inside a pack. That single envelope drives row spacing, lid clearance, terminal access, and sensor routing, and it is the reason two modules from different batches can follow the same installation sequence. When comparing what an ev battery manufacturer or a Nissan Leaf battery module supplier publishes, the dimensional line deserves the first look, because it sets the physical limits that every later decision has to live inside. Checking the full published specs of the module before planning a repair is the simplest next step.
A：VDA 355 describes a common outer envelope for prismatic battery modules used in electric vehicles, published here as 355 x 150 x 110 mm. It gives pack designers and repair shops a shared reference for footprint, height, mounting surfaces, and terminal positioning, so modules from different production batches occupy the same physical space inside a pack. It is a size and layout reference, not a rating of energy, power, or chemistry.
A：Those numbers decide how a module sits in the tray: the 355 mm length runs along the pack's long axis, the 150 mm width sets the spacing between neighbouring modules, and the 110 mm height sets clearance for the lid, cooling interface, and terminal access. Technicians use them to confirm the module lands flat, clears the tray walls, and leaves enough room to torque the busbar and route the sensor harness during the rebuild.
A：No single module format fits every pack configuration without engineering work. Matching the 355 x 150 x 110 mm envelope is the first check, but actual fitment depends on the enclosure, mounting brackets, busbar routing, sensor wiring, and BMS integration in that specific vehicle. A module that meets the format still needs professional assembly, structural fastening, and system checks before the pack goes back into service.
CATL 4S1P 177Ah 355VDA NMC Module Replacement Solution for Nissan Leaf EV Batteries
