How to choose the right button cell: LR, CR and zinc-air explained

Button cells are the small, coin-shaped batteries that run watches, car key fobs, computer motherboards, toys and hearing aids. They look almost identical — but the chemistry behind them decides which device they can power safely and for how long.

Three chemistries, three jobs

Alkaline button cells (AG / LR, 1.5V) — the AG0–AG13 range plus 23A/27A 12V specialty cells. These are the everyday references for watches (AG1/LR621), calculators, LED candles and remote controls. At TIANQIU the whole range is produced in 17 standard models from 5.8 mm (AG0) to 11.6 mm (AG13).

Lithium button cells (CR, 3V) — a single 3V cell replaces two 1.5V alkaline cells, which is why CR series dominates motherboards (CR2032), car keys (CR2025), medical devices and IoT sensors. Sizes run from CR927 (9.5 mm) up to CR2450 (24.5 mm). All models ship on child-resistant 5-pcs cards.

Zinc-air cells (A10 / A13 / A312 / A675, 1.4V) — designed for hearing aids: high capacity, stable discharge and a long shelf life, packed 6 pcs per pack.

The size table tells the story

The diameter and thickness in the model name are the physical spec — but the voltage is chemistry. Two cells with the same diameter can be completely different batteries: a 7.9 mm cell could be a 1.5V AG3/LR41 or, in the lithium range, nothing at all. Always cross-check the device’s stated model against the IEC reference (e.g. AG3 = LR41 = 392A).

Buying checklist

1. Confirm the chemistry from the device manual — 1.5V alkaline, 3V lithium or 1.4V zinc-air are not interchangeable.
2. Check diameter and thickness — a 0.5 mm difference can prevent the cell from seating.
3. Buy mercury-free — all TIANQIU alkaline button cells are 0% Hg (Hg0), certified by an MTL-ACTS mercury-free testimonial.
4. Ask for child-resistant packing for 3V lithium — EU and US retail regulations require it; we produce 1–8 pcs safety packs.

A note on safety

Button cells are not toy batteries. Keep them out of the reach of children and always store spares in their original child-resistant packaging.