'89 Geo Metro LSI (1Liter 3 Cylinder) Intermittent Starting Problem?

Most of the time it starts fine first time, however, occasionally when I turn the key to start, all I hear is a click and the starter doesn’t turn over. If I keep trying to start it, sometimes it will start after several tries, sometimes it won’t. If I try to push the car a little, sometimes that seems to help and it starts, sometimes it doesn’t help. Sometimes I have to resort to push starting if I was lucky enough to park somewhere, where it’s possible. The problem was getting really bad till where it was happening every day. I put my battery on the charger and it seemed to make the problem happen much less frequent. I also changed the starter. For a few months the problem went away, though recently it has started to resurface again.