No, they use battery back-up. Some of 3rd-party developers have gotten cheap and reverted back to passwords. One recent review I read for a newer release said the password system was TWENTY-TWO characters long. That is ridiculous.
Shining Force for the GBA comes with a battery. I have three saved files on the cart... I deleted one of them and then copied the 3rd file (the opne I'm playing) into the first slot. It seems to be working... I shall know when In ride the train home tonight.