Battery+Alternator problem.

[GarrettM]

My battery keeps dying, sometimes it will crank slowly then start up, others it will crank and then just click cause it's dead.
I jumped it and threw a multimeter on it and it is reading 13.5. Is this normal or should it be higher?
Thanks.

[redhatpat]

13.5 is normal with the car off. Running, you should see ~14.0+V.

This sounds like a dying starter motor.

[GarrettM]

No a fully charged battery is 12.6. Maybe 13ish right after it hs been on a charger and has a surface charge. I know its not a dying starter motor because all the lights inside are dim before i throw jumper on it and the radio doesn't work. Also the battery is brand new

[jlevie]

13.5'ish at idle, rising to 14v or better at 2500rpm would indicate that the alternator is okay. The question now would be what the battery voltage is when one of these events occurs. If the voltage measured at the battery terminals is much below 12.5-12.6v there's a good chance that something is draining the battery while the car is parked (excessive parasitic draw). Improperly installed aftermarket electronics (audio gear or alarms) are popular causes. If the voltage at the battery is okay you need to take a critical look at the primary power wiring & connections.