what kind of inspiron ...  and i think predicted battery life is around a year

The computer is an Inspiron 8100.  It was purchased about 2 1/2 yrs ago.   The problem I am having is that when I try to charge the battery, there doesn't seem to be a good solid connection between the plug and the back of the computer.  I am not now able to run it when plugged directly into the wall.  A local repair store person said that the receptacle in the back of the computer should be replaced and that the whole "mother board" would have to be replaced at the same time - because it is all connected!!

The diagnosis is correct - you need a new system board.

Parts-people.com has one for $250, which is about as good a price as you're likely to find.

http://www.parts-people.com/index.php?action=item&id=57&prevaction=category&previd=2&prevstart=12

Not really.