Battery voltage

[TexasExcursion]

I've looked at a few other threads, but didn't know if the voltage info is different from 6.0's and 7.3's.

Both batteries were at 12.21 volts after sitting for 15 hours.

Both batt's were 11.79 volts immediately after start.

Alternator at 12.11 volts after start.

Alternator at 13.79 volts after running for a minute.

Both batt's at 13.79 volts after running for a minute.

I had to jump start the truck twice in the past two weeks, which is why I began wondering if the batteries are starting to go. I've got the Ford repair and maintenance DVD, but that thing is just confusing. The thread on the 7.3 forum said something about voltage needed to be at 14.2 volts or the batt's were bad.

 

[Tennessee Titan]

I replaced my batteries last year when I noticed the truck beginning to have slow starts. Yours maybe on the outs as well. Try cleaning the battery posts and terminal ends on the cables to see if that helps. Good Luck.

 

[TexasExcursion]

I replaced my batteries last year when I noticed the truck beginning to have slow starts. Yours maybe on the outs as well. Try cleaning the battery posts and terminal ends on the cables to see if that helps. Good Luck.

I clean the posts and cable heads every other month, so that shouldn't be the problem. The first time I had to jump start the truck was the day after I installed the cab lights. I was also installing the exhaust at the same time so I couldn't start the truck up and recharge the batteries after having the doors open for such a long time putting the lights in. So the first jump was explainable. But a couple days later the batteries were dead for no apparent reason. Hasn't happened since.

 

[TexasExcursion]

According to my Haynes manual as long as the batteries are 12.5 volts or higher on their own and 9.6 or higher under load they're okay. This may be a dumb question, but are the batteries in the 7.3 (Haynes book only covers 7.3) the same as the 6.0??

Bueller??

 

[DaveBen]

Yes they are the same. In fact all automotive batteries are 12 volt and should follow the same readings.

Dave