wallstreet shuts down at random

i've just come to notice recently that my wallstreet is randoml turning off while running on battery power. i can tell you that the clock battery is dead and that the power adapter connector is loose enough to need something shoved under the connection to charge the computer, but beyond that i have no idea why the computer is doing this. it runs fine off the ac adapter, but while testing the battery since its eight years old and i don't know what it has for a charge, the computer would run fine and then shut off. i would have to do a pram reset and jiggle the power connector (popping from speakers and screen flashing black at this point which it doesn't do unless this power issue occurs) to get it to boot again. the battery isn't drained and nothing else is wrong with the computer. i think the clock battery is the issue and i'll have to replace it when i resolder the power adapter connection, but is there anything else inside the computer-such as the pmu-that could be causing this shut down issue?