Button and Coin Batteries Compared

Button and coin batteries are both self-contained cells, although they vary in size, proportion, and chemistry. Coin cells, as the name implies, are wider and flatter, while button cells are smaller and relatively taller. Both are compact, making them suitable for small devices.

Coin and Battery Outputs Vary Too

Broadly speaking, the size of these cells and the chemistry they use, are rough indicators of the power they put out. For example, the popular CR2032 flat coin battery with lithium-based chemistry, produces a nominal 3 volts.

Whereas smaller, taller button cells using alkaline and silver-oxide chemistries, produce a nominal 1.35 volts. Zinc-air button batteries do slightly better with a nominal 1.55 volts, although silver cells deliver more consistent performance.

We can identify both button and coin battery chemistries according to their international series codes, per these few examples:

Examples of Coin Batteries

Lithium manganese dioxide (CR series)
Lithium poly-carbon monofluoride (BR series)
Occasionally alkaline (LR series)

Popular applications for coin batteries include devices with low but continuous energy demand. Examples include wristwatches, fitness trackers, car key fobs, bike computers, and digital thermometers. As well as CMOS motherboard memory backups, and small sensors where their flatter, coin form matches slim designs.

Examples of Button Batteries

Alkaline for general use (LR series)
Silver oxide for precision devices (SR series)
Zinc-air for very high energy density (PR series)

Button batteries are common in analog watches, calculators, medical glucometers, small toys, and hearing aids using zinc-air chemistry. But silver-oxide button cells are the norm in precision timepieces, because of their stable discharge curves.

The Birth of These ‘Flat Batteries’

Button and coin batteries emerged as a response to the arrival of compact digital devices, such as pocket calculators. However, the earliest examples arrived earlier in the 1940s, when zinc-mercuric oxide and zinc-silver oxide chemistries emerged.

There was no single ‘brainchild inventor’ as far as we can make out. Although we could make a case of a kind, that Volta’s 1800 tower battery was a pile of flat coin cells connected in series.