The CR2032's are 3v, but its of no huge difference, generally the drop
off voltage for the memory retaining will be around 1.8-2.0v's so you
should be totally fine, what is on the board or was on the board
previously?      Volts are important but the millamps to allow it to
last longer are actually more important, you may want to consider
putting them in parallel if what was there is a higher ma amount
Also, check and see if what was there is no a rechargeable cell because
if so, you'll have to put a diode into the circuit to keep the power
 from backwashing into the battery and damaging it, LiON
button batteries  
like the CR series are not rechargeable and youll damage it if the
current battery is setup to be a rechargeable....
Hollandia at 
ccountry.net wrote:
  One of my computers is a 486SX. The soldered-in
battery is apparently
 failing; after a period of power-off, the time is badly off at re-start. The
 date and BIOS are so far unaffected.
 The motherboard has provision for an off-board battery. I am thinking of
 using a socketed CR2032 battery which I believe is rated at 3 volts. The
 manual for the computer describes the off-board battery as 3.6 volts.
 Is it asking for trouble to use a 3v rather than a 3.6v battery? If so,
 where are the 3.6v batteries available?
 Thanks,
 Kurt