Does charge light go out shortly after car starts & then stay off? If so,
prob battery. If it *is* staying on, check that the belt's still intact
and tensioned before you start ripping things out....

Easiest is to drive somewhere and get battery function/condition checked.
Takes a couple of minutes and shouldn't cost, especially if you end up
buying your battery there! Cheers

Sorry. I didn't include your post 1st time. Oops!
Relevant comments are in that one though. Cheers

Hi,

How old is the battery? If it's five years old (or older), I wouldn't
even think twice about replacing it "automatically." (I don't care what
kind of "warranty" is shown on the case label, the "real life
expectancy" of batteries drops pretty quickly after five years IME.)
Then have the alternator checked w/ the new battery. Weak batteries are
hard on alternators--it's not unheard of for an alternator to go out
shortly after replacement of a bad battery and the owner doesn't realize
the two events are related: the old alternator was often just holding on
by a thread. Or, if a "bad" alternator's replaced, and a "bad" battery
is left in the system, the "new" alternator may take a powder way
prematurely, too.

If the battery is newer, I'd head to the parts shop and ask 'em if they
have the equipment to test both it and the alternator to decide how much
needs replacement. Most of the bigger ones do. And, as Hippo said, the
cost is usually none to minimal if you end up buying something from
them.

Rick

Replace the battery and I bet the problem goes away.  It's
statistically far far more likely to be teh culprit.  If you haven't
replaced the battery in a few years it's due anyway.

Then, if the problem recurs after a while with a new battery, then
you'll have reason to suspect voltage regulator/alternator.

Or, if you have a shope that'll do it reasonably, have em test the
electrical system and do a quick load test on the battery.  That'd be
diagnostic.   But if you're a DIY kind of person, throw a battery at
the problem and I bet ya a quarter your issue goes away.

--
Todd H.
2001 Legacy Outback Wagon, 2.5L H-4
Chicago, Illinois USA

It does sound like your battery is the culprit, but on top of what
others have said, are the battery terminals clean? Do the headlights dim
some or almost die out when cranking?  If they just dim, it could be the
starter too.

Good luck.