My battery voltage is reading 13.46 while driving and it used to go up to 14.2 and slightly above. I have a new battery in the truck, less than a year old. Is this a sign of an alternator going bad. I do have about 130,000 miles on the truck.

 

That is normal from what you describe, the voltages will gradually drop, depending on the battery especially when it gets hotter out. But let's get more information.

Does it bump up to 14.X just after starting it for a few minutes, or just always 13.x

 

I agree, does the voltage basically remain at the 13.x number or does it on occasion, go above that?

As stated above, it should after starting rise to something over 14 volts for awhile and then certainly in hot weather, the nominal system voltage drops lower. In hot summer days, I will normally see a system voltage of about 13.2 volts; in the winter, about 14.2 VDC.

Your concern about a charging system failure is justified as there seems to be a default voltage of about 13.3 volts when the regulator fails. I say the regulator, as when it has failed or is failing, the alternator will most often still generate sufficient amps to run all the equipment. Due to the voltage limitation however, the battery will not get adequately charged.


Note I did not say fully, as the charging system even when operating properly never fully charges the battery - hence the need for a CTEK or similar and to use it every few months just to get the battery back up.

 

Thank you for posting that Bruce. You just made me feel better. I am leaving tomorrow on a 4 day beach trip with the fridge packed full of food and plan to run it constantly along with a tent fan at night and other gadgets. Of course, I figured I would plug in the IID tool today to fiddle with a few things and noticed that my alternator is charging at around 13.2-13.3V. I seem to remember that it was charging at around 14.2 over the winter, so of course I was freaked out thinking that my alternator is on the verge of failing just before my trip. Now, I'm not so sure. Perhaps this is normal? Regardless, I don't have time to do anything about it and I will have a 100W solar panel on the roof rack, so if the worst should happen, I will still have some power. Guess I'll have to keep on eye on it over the next few weeks.

 

I note the comment about running the fan and fridge I guess near 7/24 and just wondered if Virginia was also the Land of the Midnight Sun?

It is about 11:30 pm here right now and while I would not say the sun is shining, it is not exactly dark yet. I do not think a solar panel would be generating too much power at this time however as the sun is pretty low on the northern horizon.

During the day, if the solar panel makes say 14 volts and I assume maybe 5 amps, it should beable to charge your starting battery however.

I assume you will take both your IID and a voltmeter to keep an eye on what is going on.

I note on hot days here my system voltage is closer to 13 volts than 14 so yours is probably OK.

Also as I mentioned before, the regulator may fail but the alternator will still put out amps at about the default voltage of 13.3 or so, not usually high enough to fully charge the battery but adequate to run fridges and headlights etc.

 

Land of the midnight sun? No, Virginia doesn't compare to your neck of the woods, though I guess it may be a good thing that we just passed the summer solstice.

I have an Optima Blue Top aux battery wired in and that's what I will be running the accessories off of. The last thing I wanted to do was chance losing my cranking battery in the middle of nowhere. The D34M is relatively small at only 55Ah, but it was about the only thing I could find that would fit in the aux battery space with no modifications. It has been able to power my fridge for a few days in milder temperatures with no charging.

Now if only Amazon would deliver my solar panel connectors that they were supposed to deliver on Monday! Grrrr...

 

Adding some solar!! Neat..

I've noticed lately, particularly in prime that the delivery times are not at all accurate, even if stock takes 2 days to ship... ridiculous.

 

Yes, I'm excited to try it out. I mounted a 100W rigid Renogy panel on my roof rack and it fits perfectly across the rack. When I did my aux fuse box and traxide install last summer I ran some extra wiring for future solar plans and finally put a controller and some fuses inline. Now, the remaining piece is to simply connect the panel.

I agree about Amazon. I've had many many instances over the past year where they either 1. tell me that something is prime, but that the delivery day is like a week away or 2. tell me that something is prime and I will get it in two days, but then adjust the delivery date after the order (which REALLY irks me). #2 is what happened this time.

 

There are a lot of pictures of my solar setup in my gallery here if you want to refer to it. If you run into any other questions let me know.

 

Yes it does, it goes to 14.2 etc on some days and on others around the 13 plus. So that should be normal, right?