High charging voltage

[Fred_M1010]

My truck used to charge about 14.5V.
But after i toasted the old regulator and replaced it with a new one, it's charging 15.0V.
The voltage is steady all the time so I don't think anything is broken.
It's probably the spec for the new regulator that's slightly off...(it's not an OEM )

Should I bother getting a new one on warranty, or will it be just fine?
I feel there's a risk that I shorten the life of my battery.
But I rarely drive any longer distances with the truck on the other hand, most trips take only about 0.5h
And I know batteries can take some overcharging as long as it's not for too long...

[BobS]

My first question is how old is your battery? Did you had it tested? A battery that is near the end of its life will trigger the voltage regulator to work harder and longer.
The second question is what are you using to read you voltage? The normal regulator charging voltage that I used and what the manufacturers used in the 80's & 90's was preset at 14.7 volts. Some ended up at 14.8 & and a few Fords were at 14.9 which never created any problems. Allowing a +/- accuracy of 1.5% for a cheaper voltage meter/tester will give you a +/- .220 volt difference or an upper reading of 14.92 for a true reading of 14.7 volts. So to me the bottom line is are you using an expensive test meter made by Fluke or a cheap disposable one that only costs a few dollars?

[Fred_M1010]

I actually used a Fluke instrument.
I work as an electronics designer, so I'm not completely clueless, unless if it's about batteries that is
The battery is only about 2 years old and holds the charge good, but I have not tested it.

I have however relocated the regulator to inside the cab (water was seeping into it when I had it in the stock location), but I soldered the extensions, so there shouldn't be any problems with that.

[BobS]

I think you will be OK that if 15 V is your peak charging reading and after 5 minutes it drops down when the alternator replaces the power removed from the starting process. The charging system is designed to replace the power removed whenever a load is applied. If you drive the truck for 5 minutes and the voltage is still at 15 V then I would temporarily substitute another battery to see how it acts. If it acts normal then I would suspect the battery as the problem.

Years ago when I was in the alternator repair business I had a customer that had a Chevy that kept cooking the alternator regulator. He had a brand new Sears Diehard battery. I replaced the voltage regulator and in a few days it took out the regulator. The alternator bench load tested OK. When installed the alternator ran extremely hot which cooked the regulator. We substituted the battery out of his wifes car and everything stayed cool and nothing failed. He returned the battery to Sears and bought another one from the local parts store. The problem was completely eliminated after the battery was changed. I called this battery a defective new battery. Apparently it had a bad cell that caused the problem. The defective battery load tested fine at Sears when he returned it.

[Fred_M1010]

Ah, I didn't think to check it when it has run for a while.
I'll check that during the weekend, thanks for your help!

[delsilver]

If you pick up a cigarette lighter plug you can adapt leads from your Fluke multi Meter and keep a constant eye on it while going down the road.
Del

[bmoeller]

http://www.ebay.com/itm/New-LCD-Cigaret ... %26ps%3D54

[bmoeller]

Ever clean the battery connections, or the ones on the back of the alternator? Corrosion can cause the alternator to "think" a battery is weak, and needs more juice.