Battery Dying out making car clunk?

It seems that when ever my battery gets to that low point and I shift into
reverse it clunks really hard. I was wondering does anyone might know what
is draining the battery?

I have a 94 SL2 Automatic with 125,486 Miiles on it. I had the alternator
replaced last year and also did oil changes, automatic transmission fluild
change.

Does anyone have any ideas?

Thanks

 

Check glove compartment, trunk light, something in cigarette lighter socket.
A bad ALT can have a bad diode and drain the battery. Only way to check is
a amp meter between the battery cable and battery. See how much of a drain.
The battery could be going. Had one on my wife's 300m die in 4 hours.

 

How old is your battery? Maybe it's dying of old age.

 

I'm a wondering, what in the wide wide world of sports does the battery have
to do with a clunking when going into reverse????

 

Saturns have a wonky transmission setup. They rely on electronics to
shift and control the automagic tranny, and believe it or not, one of
the early signs of impending battery/alternator doom is in fact the
automatic transmission doing weird things. I have a manual so I never
experienced this, but pretty much the first thing after checking /
changing the fluids is to look into the charging system.

Problem being, reverse troubles are also a sign of impending
transmission doom