That battery leaking corrosion is like a cancer. The board may work fine for several years but then start acting flaky. I had one A4KD loose the mouse on the "Y" axis, RTC and AGA. I had to lift the 3 chips off near the battery, clean and fix the board and then solder in new chips to fix the issues. Loosing the mouse "Y" axis was the weirdest one.
Now, I have my original A4kD with no battery damage will not find the real time clock until a reboot. After that, then it saves it just fine. It started doing that out of nowhere. I have the coin battery mod on that one too. I may have to replace the 3 chips on that one too. I will see how it progresses.
What I have seen the battery corrosion do is it like to eat off the head of the pass through of certain board traces. Then as time passes, it must damage the chips.