I have recently replaced the batteries in both keys of my 2021 XC40, with no problems.
Note: if you have a “Key Tag” which enables button-less entry, the batteries in those cannot be replaced and a dealer has to supply and program a new one.

Doug
2011 Plus 4 in Rich Maroon

1972 750 “ComDom” sprinter
1958 Triton 650
1992 Triumph Trophy 900