Follow every cell, module and rack from incoming grading to the shipped container.

A storage system is built in layers. Cells become modules, modules become racks, and racks go into a cabinet or container with a chiller, an aerosol suppressant and a power conversion cabinet. A fault found at a customer’s site must be traced down through every layer to the cell lot that went in.

Production software for storage makers keeps the grading result, the laser weld schedule and the firmware version on the same serial. A good first pass follows a single module from its cell tray through weld and firmware to the end-of-line test.

Cells arrive in trays from the supplier with a lot code and a datasheet. Incoming staff measure open circuit voltage, capacity on a cycler and AC internal resistance, then sort cells into grades so that matched cells share a module. Rejected cells are quarantined and returned. A badly grouped lot gives a pack that drifts out of balance.

Assembly crews stack cells between compression plates, laser weld or bolt busbars, fit sensing harnesses and close the module. Rack builders connect modules in series, add the battery management unit, the DC fuse and contactor gear, then flash firmware over CAN. End-of-line testing checks insulation resistance, cell voltage spread and a charge cycle. Larger systems go into a container with liquid cooling and smoke detection. Commissioning notes travel with the shipment.