Community Forums

tropical36 · 10-14-2008, 07:52 AM

I wouldn't think there'd be too much of an overcharge then. Doesn't seem like you're using an over amount of water, if any.

hamguy · 10-14-2008, 07:57 AM

I have been considering installing a switch which would allow me to disconnect the house batts from the alternator charger.

I don't need to keep the house batteries at full charge while driving and the loads on them are minimal while the engine is running (I think).

We rarely drive for more than 5-6 hours at a time and if the house dropped below 12.4, I could switch the alternator connection back on.

Comments anyone?

dieselclacker · 10-14-2008, 10:27 AM

Clay if you are measuring voltage at battery terminals, 14.8 volts is too much. Correct charge rate at the battery is 13.8 to 14.2 volts. And yes the voltage regulator is in the back of the alternator, and can be replaced if faulty.

Dieselclacker

rick_od · 10-14-2008, 05:12 PM

Pat,
You are describing a good 3 stage converter/charger, not what an alternator does.

I too have 14.2 showing on the instrument cluster and 15.0 at the battery(measured with 2 different Fluke RMS meters). I don't know why there would be a difference unless the instrument cluster has its own voltage regulator.

I don't put enough miles on my RV to worry about it....except

I don't like the idea of running my fridge(gas absorption not compressor) on gas while driving. I don't like it because my HWH is at the right rear of my RV and if I were rear-ended, I would have a propane fire for sure. I installed a off the shelf inverter to power the fridge. The reason I noticed I had a high charging alternator is because, as the VDC would go up with the alternator, the VAC output on the inverter would go down(below 108 VAC). The fridge does not like to work below 108 VAC.

Rick

hamguy · 10-14-2008, 05:39 PM

You would be VERY unlikely to have a propane fed fire since in the event of a line rupture, the tank internal safety shutoff valve would stop the flow of gas.

There might be a 'poof' from residual propane but it likely wouldn't even be noticed!

FreshAir · 10-14-2008, 06:26 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by rick_od:
Pat,
You are describing a good 3 stage converter/charger, not what an alternator does.

I too have 14.2 showing on the instrument cluster and 15.0 at the battery(measured with 2 different Fluke RMS meters). I don't know why there would be a difference unless the instrument cluster has its own voltage regulator.

I don't put enough miles on my RV to worry about it....except

I don't like the idea of running my fridge(gas absorption not compressor) on gas while driving. I don't like it because my HWH is at the right rear of my RV and if I were rear-ended, I would have a propane fire for sure. I installed a off the shelf inverter to power the fridge. The reason I noticed I had a high charging alternator is because, as the VDC would go up with the alternator, the VAC output on the inverter would go down(below 108 VAC). The fridge does not like to work below 108 VAC.

Rick </div></BLOCKQUOTE>

Rick, you are correct as that is from a typical 3 stage charger of which alternators and their voltage regulators kinda achieve the same thing.
Normaly alternators are thought of as charging at a rate of about mid 13 volt range to the 14.2 volt area.
But actually this is a better description of what to expect when measuring voltage.

The actual output voltage produced by the charging system will vary depending on temperature and load, but will typically be about 1-1/2 to 2 volts higher than battery
voltage. At idle, most charging systems will produce 13.8 to 15.3 volts with no lights or accessories on. This can be measured by connecting the positive (+) and negative (-) test leads of a voltmeter to the battery posts while the engine is running.

I'm in no way saying you may or may not have a problem. Just be careful your just not chassing your tail. Take it to a shop and have an alternator/electrical system check done.
Pat

Here

cannon man · 10-15-2008, 05:11 AM

glad to see this post. had very same problem with our 04 w20. 14.8 at the batteries. couldnt keep water in them. the alt never tapered off. w/h said take it to repair station. did that n they said w/h said no problem. go figger.any dimwit knows a constant 14.8 is way too high. just ask the battery makers. our new rig is doing the same thing. just took a 2000 mile trip. filled batts before we left. got home n could not see water in any of 4 house batts. you guesed it 14.8 at the batts. W/H get your act together!!!!!!!!!!!!

tropical36 · 10-15-2008, 06:11 AM

Has anyone ever contacted GM on this? I mean who supplied the alternator? Did it not come with the 8.1 Vortec engine? I'm also wondering what the difference is for my 130amp unit on my Chevrolet P chassis. I don't think I have that problem, but I'll put a digital meter on the batteries, the very next time, I start it up, just to make sure. I only say this, because the voltmeter in the dash cluster always shows under 14v. My old pace arrow had an external regulator and the dash meter was lucky to stay in positive territory when things were turned on.