Button Cell (Coin Cell)

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Button cells maybe also be known as coin cells or watch batteries.


The insulated top cap of a button cell is the negative terminal, the base is the positive terminal.

Internal Resistance

The internal resistance of a coin cell battery starts of at a rather large 10Ω. This then rapidly increases as the batteries energy is consumed. Where high pulse currents are needed, coin cell batteries can be used in conjunction with high-valued capacitors.

A rule of thumb for coin cell batteries is that 10mA is the maximum current draw.


Silver Cell

Silver cells have a very stable output voltage over the lifespan of the battery.

Common Types

CR2032. CR2025.


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