Those "integrated" CMOS devices were used on quite a few motherboards back in the 386/486 era. Cannot remember the manufacturere - but when the internal battery died you were cooked. I believe it was Dallas Semi. Some could be taken apart and a new battery soldered in. Sometimes you could cut the top off and solder wires to the 2 up-bent pins and connect a standard c-mos battery, and some guys just replaced the dallas with generic RTC chip -and an external battery.
Pain in the ARSE, for sure.
Most I saw were not even potted - just built into a glued or welded plastic box.