House Battery Charge While Underway

Our coach engine alternator charges my batteries .

I know this because i have a separate DC Voltmeter on the house batteries & when i start/run the coach engine i see the voltage on my meter increase (matching the output of the engine alternator), turn the engine off & the voltage displayed on the meter goes DOWN, displaying the voltage contained in the batteries.

when my generator is running it also charges the house batteries (assumed coach engine is off).
I don't have less than 40 bucks tied up in these meters -

He probably has a 160A alternator and his batteries should be very near if not fully charged in 300 miles of driving with minimum house loads. House loads especially the inverter and headlights will decrease the amps into the batteries. His batteries are likely in the rear near the engine but wiring losses can always be something to check.

OK It's called Full Charge:

Full Charge (Battery Saver™ mode): The fourth stage occurs after four hours in the Float Charging stage. The Full Charge stage is designed to keep batteries fully charged over long periods and prevent excessive loss of water in flooded batteries, or drying out of GEL/AGM batteries. In this stage, the charger is turned off and begins monitoring the battery voltage; if the battery voltage drops low (12.7 VDC or less), the charger automatically initiates another four hours in float charge.

About your battery spark: There are often a number of devices that cannot be turned off like smoke and propane detectors. The worst offender on my rig is the ME2012 as it has a idle current of 0.3A and this cannot be turned off. This is excessive of course but Magnum calls it a design tradeoff. Unfortunately it's one of about 5 "design tradeoffs" or problems as I think of them. Here's the math for a month of storage: 0.3x24x30 = 216AH or about 50% discharge of my batteries.

Because my rig is stored w/o power and under a roof so that the solar doesn't work I installed a battery cutoff switch on the negative post to resolve all of the unwanted loads.

Back to the ops question I think what you are describing is normal. I have 2 6V batteries and 180 amp alternator and after a week of dry camping a five hour trip home won't completely charge my batteries. You have 4 6 V batteries and twice the amp hours to put back in those depleted batteries. With your motorhome running if you read 14 V at the chassis battery and 14 V at the house batteries your solenoids are working their way they should. It always takes me overnight to recharge my batteries with a 40 amp charger. Many on here talk about a larger wire size from the alternator to the batteries as being helpful and also external alternator regulators as a means of getting more amps to your batteries while driving. As far as parasitic draw's go these are easy enough to check by disconnecting your negative cable and putting your ammeter between the cable and the negative post I have .4 A of parasitic draw. I had over 1.5 A until I found what was causing these parasitic draws.

Getting a small spark on the negative is usually not a problem. Lots of capacitors loading up. You need to actually measure the current draw to make a determination.

DSDP Don wrote:
"FIRE UP"....ON my Monaco I never saw the "Full Charge" on the monitor, but I've seen it a few times on my new coach. Usually, after it sits all day in good sunlight (300 watts solar power) and plugged in.

Don,
I think I've got a small but, larger than parasitic draw on my house batteries. I've had those batteries out while servicing them and, when I hook them back up, I get a small spark on the negative. I have checked all around, compartment lights, interior lights, water pump, everything and, so far, I cannot locate what ever it is that may be putting tiny draw on them.

And, if there really is a tiny draw on them, I will NEVER SEE THAT FULL CHARGE on my ME-RC Monitor for the Magnum. I'll have to keep investigating. Thanks.
Scott

"FIRE UP"....ON my Monaco I never saw the "Full Charge" on the monitor, but I've seen it a few times on my new coach. Usually, after it sits all day in good sunlight (300 watts solar power) and plugged in.

Well you have TWO questions
Yes the batteries should be charging, and yes the magnum will say inverting unless you turn off the inverter function
It only makes charging voltage when it has 120vac ..either shore or generator, so it automatically goes to invert when not charging unless you turn invert off
You are driving so the inverter sees good voltage, no need to shut off inverter, if you have nothing turned on, there should be very little drain
My alternator voltage is not as high as I would like, but with solar and generator, I usually don't need to worry about it
It's not how many miles you drive it's how many hours, do you make that 300 miles in five hours drive or eight, it's hours of charge time not miles of charge time
Not enough hours of driving give it some more generator run time

prstlk wrote:
Once again I come to the best wisdom source to be found.

07 Holiday Rambler, 4 6v house batts, Magnum controller, Magnum inverter 2012.

Situation is, when we dry camp we run the gen for 2 hours when we stop, and another 1 hour in the morning. (might be more if we need the air)

Question is this. Should the house Batts not recharge from the engine alternator if we are driving from A to B for 300+ miles?

We have found looking at the control panel we are inverting going down the road.

Is there something we need to do different with the controller?
I find it hard to believe that after 300 mi we should arrive without fully charged house batts.

Thanks for all you do, you are all the best!

CA Traveler wrote:
Start your engine, wait about 2 minutes and then measure both battery banks voltage. You'll likely find that the isolation solenoid is not working and failure of the contacts is common.

Scott, The ME2012 fourth stage is No Charge and is automatic. This occurs with fully charged batteries and minimum draw. The fifth stage is Equalize and is manual.

You know, I've read that the ME2012 is SUPPOSED to go to a "FULL CHARGE" status, after the house batts have been brought up to and, are staying at, a full charge for a while, usually after 4 hours of float charge. But, I have never, ever seen my remote, display that "Full Charge" status. This is why I stated what I did. And, yes, the actual fifth one is, EQUALIZATION. My fault.
Scott

nice that the last few responses are from people who actually own Monaco products, they are a little different than other manufacturers.

"Middle range monaco's" such as ours, have a BIG relay in the battery compartment, pass side behind the back tires. A "trombetta continuous duty solenoid" It looks like the starter relay on an old Ford.

It ties both battery banks together. Controlled by the boost switch, as well as by whichever of 3 or 4 different IRD or BIRD systems that could be installed on your Monaco Product.

Ours is an 08, and had the newest BIRD system (bidirectional) It also had a bad trombetta relay. Once that was replaced, it does always charge all batteries from any available charging source.
Not sure what system your '07 would have.