Photoflash battery

A photoflash battery is a specialized zinc-carbon battery optimized to provide a high electric current output for a short duration of time, such as required to fire a flashbulb. Service life for this battery in flashlight service is short, since flashlights required a lower but continuous long duration current.

Photoflash cells were in production during the flashbulb era, and were slowly phased out as alkaline cells came into general usage. The photoflash cell was produced as a 1.5 volt size D, C Size and AA Size.

The cathode (the material packed between the carbon rod and zinc shell) of a zinc-carbon cell is generally made of powdered carbon black (or acetylene black), manganese dioxide and electrolyte. The MnO₂ to carbon ratios vary between 10:1 and 3:1 for general purpose cells. A 1:1 mixture is used for photoflash batteries. This allows a high current output with intermittent use, perfect for photoflash use.These cells have reduced capacity compared to those with a higher content of MnO₂.

Another common type of photoflash battery was a higher-voltage series assembly of cells, often totalling 22.5 volts, used in battery–capacitor flash units. The battery slowly charged a capacitor, which then was discharged through a flashbulb to provide the heavy pulse of current to set off the bulb.

See also

• List of battery types

External links

• Cell Construction - Information on MnO2 ratios