batter voltage tests

[2mtrucks]

I tested my batteries today. Engine off the front is approx 13.0vdc and so is the rear. Engine running the front is approx. 14.5 vdc to 15.3 vdc and the rear is the same. Is this normal resting and charging voltage?. The reason I checked it is because the gen 2 light will periodically flash on while driving and the gen 1 lite has never come on when the ignition is turned on. However, it has always started and never needed to be jumped or put on a charger. Any guesses?

 

[doghead]

It's normal.

 

[cranetruck]

For a more definite test, get a hydrometer and check the specific gravity, no better way to determine the state of charge....

 

[cranetruck]

More on the "state of charge" testing, keep in mind that it's a chemical process and the proportion of acid to water tells the story.
If the open circuit voltage test does not agree with the specific gravity test, then your battery may be sulfated. Running a pulsetech(?) solargizer device for a month or so may reverse the sulfation.

Check the PS magazine section (still on the old SS site) for more on battery care.

 

[ida34]

Newer battery chargers have a battery "renewal" setting that is really just desulfating for the uninformed. It takes about 24 hours. If it is to far along to do any good it will tell you this also.

 

[cranetruck]

24 hours? It probably takes a lot longer from what I have read/experienced. Years ago I tested one of the Pulsetech (120 VAC powered) and noticed no change after a week, so I sold it....now I think a month would be a reasonable time to run it. Oh well...

Edit: Sulfation is a normal part of the battery discharge process. It's reversed when recharging takes place.
The stuff that accumulates from self discharge "hardens" and will not normally revert and that's where the electronic pulsing comes in, to get rid of the stuff that's not normally reversed.

 

[2mtrucks]

Batteries are good but Im concerned they are being overcharged. My voltmeter reads at the very high end of green. Battery terminal voltage readings with engine running are now consistently about 15.5vdc each and collectively about 31.0 vdc. Do I need to have the alts rebuilt or the regulators changed? I checked every connection on the truck that would be related to charging, including the grounds and all are good. Just trying to learn as much as possible because there is no one anywhere near me who would work on this truck. In fact my local Ford dealer made a couple jokes about it when he saw it. I told him when he can sell me a 1 ton diesel truck with 6k miles and no rust for 4700.00 to call me.