Label your cells — names, serials, and QR codes

Names vs. serial numbers

• names=[...] — your identity for a cell: the marker-pen label, the batch ID, “B7-01”. This is the primary identifier for lab-built cells, which have no serial number.

• serial_numbers=[...] — the manufacturer’s identity, printed on the wrapper of a commercial cell. Only use it for that; do not invent serials for cells you built.

Use either, or both in parallel (same length, matched by position):

import battinfo

ws = battinfo.workspace(".")
spec = battinfo.CellSpec(manufacturer="My Lab", model="COIN-NMC811-A",
                         format="coin", chemistry="Li-ion")

# lab-built coin cells: names only
cells = ws.add("cell", spec=spec, names=["B7-01", "B7-02", "B7-03"])

# commercial cells: manufacturer serials, plus your own shelf label
bought = ws.add("cell", spec=spec, names=["shelf-A-04"],
                serial_numbers=["INR-9F3K72"])

ws.save()   # mints one permanent IRI per cell

What goes on the label

After ws.save() each cell object carries its permanent IRI; the last path segment is the cell’s UID and its first six characters (dashes dropped) are the short_id — the thing to write on the cell when a full IRI will not fit:

for cell in cells:
    uid = cell.id.rsplit("/", 1)[-1]          # e.g. gm6p-mrc6-p6cc-0m18
    short_id = uid.replace("-", "")[:6]       # e.g. gm6pmr
    print(f"{cell.name}: {short_id}   {cell.id}")

The UID alphabet deliberately omits i, l, o, and u, so a handwritten short ID survives being read back from a photo (Identifiers). The short ID also does real work later: name your data files after it and ws.add("test", datasets="glob") matches files to cells automatically.

QR codes

A QR code holding the cell IRI turns any phone camera into a record lookup. segno is a one-file QR library — it is not a BattINFO dependency, so install it separately (pip install segno):

import segno

for cell in cells:
    qr = segno.make(cell.id, error="m")            # the IRI is the payload
    qr.save(f"{cell.name}-qr.png", scale=6)        # or .svg for vector labels

Print the PNG/SVG next to the name and short ID. Scanning resolves the IRI through w3id.org: machine clients get the record as JSON-LD; a browser lands on the cell’s registry page (behind the sign-in gate while the platform is in soft launch — see Identifiers).

Printable label sheets: the Battery Genome platform (battery-genome.org) generates printable QR sheets for registered cells, so you do not have to lay out labels yourself.