Choosing a pouch shape: flat, round, curved or ultra-thin
Shape is the first decision in a LiPo purchase, because it is set by the enclosure. This guide compares the four shape families and the questions each one raises.
Dimension-callout pouch outline — the site's recurring diagram motif. It is a schematic, not a photograph of a product, factory or customer project.
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Flat is the default. A flat pouch cell suits any rectangular cavity and offers the widest choice of sizes and capacities — the 512-model LiPo family is mostly flat cells. If your device has a rectangular battery compartment with a defined thickness budget, start flat and only move to a special shape if flat fails on thickness or on the cavity outline.
Ultra-thin is flat taken to its limit: cells around a millimetre thick for cards, tags and the slimmest wearables. The constraint is capacity — a very thin cell holds a small charge — so an ultra-thin inquiry must state the runtime target as well as the thickness budget. Round suits circular cavities in compact devices and wearables, where a rectangle would waste space and sit unevenly. Curved follows a band or bracelet, using volume a flat cell would leave empty and keeping the device comfortable.
The factory profile describes custom dimensions and curved shapes as part of its custom capability, so a shape that no listed model matches is not a dead end — but it is a drawing question, not a catalogue question. Send the cavity outline, the maximum thickness and the radius if the device curves, and the shape conversation can be answered from geometry rather than from general claims.