QualificationExact sourced interface · in-enclosure thermal behaviour unqualified
ArticleLP552035 · lithium-polymer
ProtectionIntegrated protection circuit fitted
Capacity350 mAh at 3.7 V = 1.295 Wh
Voltage window3 V cutoff → 3.7 V nominal → 4.2 V full
Body19.6 × 36 × 5.2 mm
Swell allowance0.52 mm of pocket depth beyond the cell, reserved by the enclosure
Terminationjst-ph · 100 mm leads
Geometry authority: declared-envelope
Datum: Pouch back face at z = 0; leads exit +Y; corner at origin.
Vendor-listed envelope, mass, capacity, protection behaviour and chemistry limits for Adafruit 2750. There is no manufacturer drawing or datasheet behind it: no dimensional tolerance, no cycle-life curve, no thermistor. The solid is the stated envelope as a plain slab; foil seal skirt, tab exit and protection-circuit bulge are unmodelled. swellAllowanceMm is a flat 10 % of thickness stated as a catalog rule, not a manufacturer ageing figure. Cable length is Adafruit's stated ~100 mm. Capacity, internal resistance, real swell over life, self-discharge and thermal behaviour remain unmeasured.