Normal Battery Voltage

[scchang]

I've searched around here but can't find the answer to this, so please don't flame me for asking: What are the normal voltage values for the battery when testing from the OBC?

I get 11.4 and 13.3 when running. When I rev the engine or turn on various electronics, the 13.3 does not really change.

The issue I am having is in a 2001 4.4i with 158,000 miles. The battery is less than a year old but has been discharged to requiring a jump twice. The alternator is original. I had some aftermarket electronics that have since been disconnected, but continue to experience the battery drain. It usually occurs after the vehicle hasn't been driven for a couple days or more. I've read the various posts regarding pulling fuses, etc. but thought that if my voltages indicate a bad battery or alternator, I could address them first.