Chassis Batteries Charging

[diggermik85]

Probably a dumb question but here goes. Does anyone know if the engine alternator charges the chassis batteries as you are driving down the road? My chassis batteries don't seem to be charging unless i am plugged in to shore power or running the generator. Thanks

[Dunner]

Most do and what you really mean is house batteries. The chassis battery is the one that starts your motor. Mine does and came that way. It also charges the chassis battery while on shore or generator.

[skibum61]

Most motorhomes have two sets of batteries, the chassis batteries and the house batteries. The chassis batteries are used by the engine for starting, head lights and other driving functions. They are charged by the engine alternator while driving. The house batteries supply power for interior lights and other inside uses. They are charged by shore power when the RV is plugged in. I have not seen any motorhomes that charge the house batteries from the aternator.

[Dunner]

My instruction manual says the house batteries are charged by the alternator and so does the search function.

[mahon1993]

You house batteries should charge while driving. If they are not something is wrong. A simple test would be to check the voltage of the house batteries when you are not plugged into shore power. You should see 12 plus volts. Then start the engine and see what you get. The voltage should jump up to 13 to 14 volts indicating that the alternator is charging the batts. Different MH use different ways to charge the house batteries. Some have a battery isolater and some, like mine have a seperate output terminal on the alternator for the house batteries. I don't think there would be a blown fuse causing your problem, but there could be.
Greg

[walt2137]

Quote:

Originally Posted by skibum61 Most motorhomes have two sets of batteries, the chassis batteries and the house batteries. The chassis batteries are used by the engine for starting, head lights and other driving functions. They are charged by the engine alternator while driving. The house batteries supply power for interior lights and other inside uses. They are charged by shore power when the RV is plugged in. I have not seen any motorhomes that charge the house batteries from the aternator.

Well I have one that charges the house battery's from the engine altanator and all the Monaco pushers that I know of will charge the house battery's after the chassis is fully charged. It is according to the year and class of Monaco coach on how it is done.
Digger what coach and year do you have?

[Cayman09]

Digger, here's an extract from my Owners Manual (Cayman 09)

Your's should be similar.

""The motorhome has two 12 Volt DC systems:
chassis and house. These two systems, for
the most part, are separate from one another.
The house system does not operate engine
functions; the engine system does not operate
house functions. However, within the two
systems there are some inner connections. For
example: While the motorhome is driven the
alternator on the engine will charge the house
batteries. Likewise, while the motorhome is
plugged into shore power, or the generator
is running, the chassis batteries are being
charged. Each system will supply 12 Volt DC
power to the 12 Volt DC distribution panels.""

[bborc]

I don't think there is a mh that does not charge the house batt. when the engine is running. I had mhs back in the late 70's that charged the house batt, and they were cheap mhs. Always had problems with the batt. isolators though.

[mahon1993]

Friends of ours had trouble with the alternator on their Monaco and had it replaced with one that did not have the extra output connection for charging the house batteries. Was your alternator ever replaced with the wrong type? Or the second output for the house batteries could be bad. Another problem I have seen is loose or dirty connections on the alternator. They would be worth checking.
Greg

[deSanford]

My 2011 Navastar Monaco Cayman charges the chassis battery until it reaches 13.9 volts by the engine alternator. Then a sensor sends 12.6 volts to a solenoid that allows the charging current to go to the house batteries. When I'm plugged into shore power only the "house batteries" are being charged by the inverter. So I added a "trickle" charger that takes voltage and current from the "house batteries" and charges the "chassis" battery. Just added a solar panel so that without the engine alternator charging the batteries the solar panel will when there is NO shore power. Panel is also very helpful in keeping batteries charged while coach is placed outside for storage. Hope this is a little clearer then mud to understand Diggermik85.

[moisheh]

Yes , no ,maybe. Take your pick for the correct answer. Not all Monacos are alike. Many of the entry level units have no means of charging the Chassis batteries when you are on shore power. All MH's should charge the house and chassis batteries form the alternator. No special alternator is required. Monaco uses many different methods of charging the chassis batteries when you are on shore power. Some older units have the Lambert system. Some use the Big Boy Intellitec system. Read your manual.

[diggermik85]

Merry Christmas!!! thanks everyone for your suggestions. Walt, i have a 2009 Cayman and yes i was talking about the wrong batteries i will check everything out tomorrow and see what happens Thanks again

[Dunner]

Good luck and don't be afraid to ask questions. There is no one smarter than all of us together.

[rpasetto]

diggermik85, You should be able to get a wiring diagram for your coach from Monaco Tech Support. They'll also be able to answer specific questions about your coach and they've been pretty good as of lately.

Most Monacos have a system which will charge both house and chassis batteries (from the alternator) with the engine running, giving priority to getting the chassis batteries charged first, of course. There are however some models which do not charge the chassis batteries from the alternator. In order to do so a supplemental device, like the Xantrex Echo oCharge, or a separate 110v charger would need to be added. Monaco shoule be able to tell you what your coach has; other members with a coach like your 09 Cayman may be able to advise as well. By the way, the owners manual for your coach should be available online at Monaco's website in PDF form. A search of that PDF may help answer this and a lot more of your questions.

Welcome to the forum and enjoy your travels.