To generate or to alternate that is the question, or at least A question...

[Geom]

I wonder if an engine's alternator can properly charge house batteries at all...

John

I was wondering the same thing myself. I just assumed the voltage regulator took care of it, but was wondering if it really charged them correctly. From @Jeremy's post, it looks like it doesn't, at least not well.

@Jeremy, thanks for posting that link. Which of those 4 models did you end up with? The mid line one (pro-d) looks pretty good because it also has alternator heat detection, something I'd considered getting anyway.

@Geoff, thanks for posting your setup with the secondary alternator. I guess since my alternator is already 12v and is capable of 300amp output, it'll be sufficient for my present needs; but something like that might prove quite useful later down the line, if I expand battery capacity and need 'more power' as Scotty would say

[Jeremy]

@Jeremy, thanks for posting that link. Which of those 4 models did you end up with? The mid line one (pro-d) looks pretty good because it also has alternator heat detection, something I'd considered getting anyway.

The type I've got is the one they're now calling the 'D' - looks like the range has expanded considerably since I bought mine!

I should also mention that mine is still sitting in it's box waiting to be wired up, so I can't testify to how well it works yet.

Jeremy

[TomC]

I wanted to run the setup Geoff has on his V730, but my bus was a Portland, Or bus that did not have A/C-hence the A/C drive was never installed in the transmission-the gears are not there. If you have the PTO shaft-then yes that is a great way to power your generators.

Remember that when running, typically the regulator should be set at 14.1 volts (to be acceptable, for instance with AGM batteries). A 300amp alternator at 14.1 volts can deliver up to 4,230 watts, not the 3,600 watts at 12vdc.  Good Luck, TomC

[BJ]

I'm sure I'll hear about this, BUT.  As an old entertainer coach driver we used our generators 24 7 while on the road. There a/c units, refrigerator, stereo, tv's running. Plus I have seen those relays you talk of fail and really screw things up. Then there is the cost of house batteries, including everything that goes to run the coach off he batteries, and not to mentioned the maintenance of the batteries. I have no relays on my coach to change from shore power to the generator. I have a 50 amp switch that I manually switch to one of the other. My rig is full electric and having other propane coaches I am thrilled I don't have to mess with that anymore. I use house appliances, thank god finally no more crappy rv appliances. I can go down the road with my clothes washer running, my generator is already running which is diesel 15 kw with a smile on my face Boo to all that mess of house batteries. If I need to start the engine and the batteries are dead, my gen is running so I hook up my batt charger with a 200 amp start on it and I am on the road again.   see ya   BJ

[Jon]

Don't worry about the charging protocol for house batteries (or chassis for that matter) from the alternator.

I have had the worst possible combination charged from the bus alternator and have no issues ever. I have a 50DN with a 27.7 volt regulator setting. My Delco 1150 batteries call for 14.25 charging voltage and then a 13.4 volt float. They aren't getting either.

The house is Deka 8D gel with slightly different voltages but specifically 13.4 or thereabouts when charged. While they may not get the perfect charge they do get a 3 stage proper charge from the inverters when the generator or shore power is present.

Both sets are charged through a large isolator. The Chassis has a dedicated three stage charger if needed.

[Lin]

BJ- Your setup works for you because of the kind of use you designed it for.  It would not work for our dry camping. Hence, I like propane.  Manufactured RV's must try to meet the needs of a range of possible customers.  We don't need to do that.