OK folks here we go. Im about to make a 1900 mile trip (Cali to Illinois EAS USMC) in my 92 K5 and my eyes and ears are on full alert. My battery voltage gauge seems to drop significantly during the 30 miles drive from work to home was at night. Defroster on, lights on (its night time), radio on and loud (bcuz im deaf). On initial start up voltage appears on gauge just shy of 14V. By the time I get home its about halfway between 9/14. I pulled out the volt meter and with everything running voltage was sitting at 12.8. I turned off the defroster it went up to 13.2. I turned off the lights and it climbed to 13.6/13.8. Is the drop im seeing with everything going normal or am i being waaaay over worried about this. Autozone ( don't start i know....) tested the battery, starter, and the alternator because i wanted to know if it was all good. Battery registered 89% good. So again is this drop normal and im being a candy a(butt)** or should i replace the battery. Thanks for the input, advice and probably rousing. Heading home and want no more issues than the cost of fuel.

 

you should be fine, at 12.8 its still charging the battery. If your still concerned just dont run everything at once

 

Fair enough thanks boss