I replaced the batteries on my three US Dreamcasts earlier this year. Each one had a different sized battery. My VA0 revision console, with a date code of July

I replaced the batteries on my three US Dreamcasts earlier this year. Each one had a different sized battery. My VA0 revision console, with a date code of July 1999, had the largest battery with a Sanyo ML2430. My other two were VA1 revisions made in March 2000, and one had a Maxwell ML2032 and the other had a Panasonic ML2020. (With coin cells, the first two digits is the battery's diameter in millimeters, and the last two is the thickness in 10ths of a millimeter. So a 2032 is 20 millimeters wide, and 3.2 millimeters thick.) Apparently, Sega of Japan planned for a US$299 price point, but Sega of America wanted to sell it at $199, so SOJ ended up doing redesigns on the internals to bring down the manufacturing cost. I guess using cheaper batteries (whatever they could get a hold of, screw consistency) was one way they did that.