Alternator going bad? Options

[gabyz]

notice this when I drive at night with healights on..

whenever I brake which causes the taillights to go off, use the A/C fan, even the turn signals, my headlights dim very noticably. It's like anything electrical that is turned on drains a large amount of power from everything else. Is this normal? I've had a Corolla before and never had that happen before. Thanks

[alltracman78]

A sitting battery isn't going to have 14.5V.
With the engine running you should have that at max.

Just checking the voltage won't give you a good idea of battery condition.
Have it load tested [pretty much any actual battery tester is a load tester].
Hatchys right about the water. If you have a battery that you can remove the vents check to make sure the electrolyte inside [water/acid] is up to the right level.
http://images.google.com/imgres?imgurl=htt...ficial%26sa%3DN
Make sure you use DISTILLED water, not tap water. It's just pure 100% H2O that you can get at pretty much any grocery store.

Also make sure BOTH battery connections are tight and clean. Make sure the top of your battery is clean too.

If the battery is ok, get the alt tested before you assume it's bad.
While it's most likely 1 of those 2 things, there is a chance it's something else.