Why did so many early / cheap calculators use 9V batteries?

[Massimo Gnerucci]

(03-29-2018 07:34 PM)Maximilian Hohmann Wrote:  

(03-29-2018 07:03 PM)Dieter Wrote:  But it's not if you look at AAA cells.

In my recollection of the 1970ies and 1980ies AAA cells were almost nonexistent. You needed to go to a camera store and buy them at 3 or 4 German Mark a piece (or 2000 Italian Lire as I lived in Italy then). The usual places where one went to buy batteries did not have them. 4,5V "flat batteries" yes, because they were common for flashlights, but AAA I don't remember at all. And I never owned anything that needed AAA cells then. My grandmother had a calculator "Triumph/Adler Lady" with these batteries, but that must have been in the very late 70ies, and it was the first time I ever saw this kind of battery.

These are also my recollections from the same time period, in the same country.