On Wednesday, 27 September 2017 16:15:22 UTC+1, James Wilkinson Sword wrote:
On Wed, 27 Sep 2017 16:08:23 +0100, whisky-dave wrote:

On Wednesday, 27 September 2017 15:08:08 UTC+1, James Wilkinson Sword wrote:
On Wed, 27 Sep 2017 14:58:40 +0100, whisky-dave wrote:

On Friday, 22 September 2017 12:10:36 UTC+1, James Wilkinson Sword wrote:
Is it cheaper to make batteries cylindrical or something? If they were square in crosssection, they wouldn't roll off the desk.

I think the real reason was because AA was meant to replace SP7/HP7s so if they'd made the AA square they wouldn't be able to be used in the products that took SP7/HP7s

Never heard of those, and Google just produces AAs which are also listed as being an SP7/HP7. Have you got a link to one?

https://en.wikipedia.org/wiki/AA_battery

Historically, it is known as SP7 (Standard Power 7) or HP7 (High Power 7) in official documentation the United Kingdom, though it is colloquially known as a "double A battery".

So AA didn't replace SP7, it's just another name, of which there are about 20.


Which is why AA had to be the same shape and size and it didn't replace SP7 it mostly replaced HP7 .

https://www.vintage-radio.net/forum/...ad.php?t=95550