bios information is stored in the realtime clock chip (RTC) it has a non-replaceable (replaceable if you are brave/skilled/stupid enough) epoxied battery inside.
new chips used to be available from maxim (DS12B887) but i don't know where besides e-bay you'd find one nowadays.
the chip number to search for is "12B887" manufactures will put all kinds of extra letters and whatnots all around it... such as your oden brand (OEC12B887A)
if you are brave enough, you can chop the outside off and remove the battery from the "core" of the chip and solder a 2032 or something to the leads. a word of caution, one end contains the battery...the other an oscillating crystal for the clock... if you damage the crystal, it will be toast. best to try and source a replacement first... then hack.