Where to Get Optima Batteries 8171-767 (DS46B24R) YellowTop Prius Battery

I'm a noob and know that's not true.
Are their techs not able to read and differentiate between batteries?
Trunk battery is 12 volt; that's it.

My silly question; why would Toyota make the posts another smaller size?
(and don't give me the "To save lead" line. I ain't buyin' it.)

 

The larger posts are called SAE posts (Society of American Engineers)
The smaller posts are JIS posts (Japanese Industry Standard)

I assume small batteries in Japan are all JIS while large batteries are SAE.

 

Jimbo nailed it. Back in the "olden days," pretty much all cars made in Japan used the JIS "pencil posts," so it's not out of line for them to appear in the Prius. Not sure if they ever EXPORTED pencil post vehicles to the U.S. (until the Prius, that is), but, IIRC, the Prius was sold in Japan for several years before they started exporting to the U.S.

I would imagine, they had them in the original "made for Japan use" Prius and just did not change them when they started exporting.