Can I charge the house battery with the engine alternator?

[heyobie]

I have a Class C, 1988 Ford 350 Travel Master with one good house battery. When I boondock in cold weather, my propane furnace can get me thru 1 night. If I want to drive to another non electric spot,I'm out of electric and therefore heat.

I am considering adding another house battery as a solution. But I want to know if it is a simply solution to charge my house battery using the engine alternator.

Also, a battery cable has been run from the house battery into the engine. It is terminated in the engine bay but not connected to anything. It looks like factory work. Maybe a factory option.

Thanks for looking

[heyobie]

My 88 is in much better shape than you have deduced. My Onan generator works great. The inverter/charger has been updated. This unit only came designed with one 12v house. I now have 2 in parallel.
My issue was that the charging system with the car alternator had been kinda stripped out and modified.
With everyone's help here, I got it straightened out and now it works perfectly.
So I am good to go.

[Bordercollie]

If you can afford it, try to find a local RV repair service that can restore your rig's 12 volt DC power system. It should include two 6 volt RV "house" batteries connected in series for 12 volts, a battery converter/charger that converts 120vac "shore power" to 12 volts DC to power your interior lights and furnace blower and electronic appliance controls as well as to charge your house batteries, and a device to connect your chassis alternator to charge your house batteries when you are driving/running the engine. If you have an RV generator installed, the system will connect the AC 120volt generator to your converter/charger so that the generator will charge the RV batteries and provide 120 volt AC to operate your roof Air Conditioner, microwave oven and other 120vac items while it is running. The above describes a typical Class C motorhome electrical system and how it works.

[JaxDad]

heyobie wrote:
I just feel better with a switch while I'm trying to figure out how this works. One of the things is don't know is whether I have a regular solenoid starter switch or a battery switch (which is just a starting solenoid that can handle continuous power). The previous owner had a push button switch which tells me he was using it to jump the MH. But the batteries were not connected. I just ran it for an hour and everything seems fine. But turning the switch off makes me feel better.

The push button is a normal thing, it allows you to start the engine from the house battery in case the chassis battery goes dead or needs help. Kind of like hard-wired booster cables.

[enblethen]

In my old Itasca, the switch was three position. Center was off, momentary one direction was for jumping to start rig with aid of house battery, other position was for charging battery.
You could use a single pole on/off switch with light. Connect it so when in on position, switch would be lit meaning battery charge relay is energized.

[heyobie]

I just feel better with a switch while I'm trying to figure out how this works. One of the things is don't know is whether I have a regular solenoid starter switch or a battery switch (which is just a starting solenoid that can handle continuous power). The previous owner had a push button switch which tells me he was using it to jump the MH. But the batteries were not connected. I just ran it for an hour and everything seems fine. But turning the switch off makes me feel better.

[enblethen]

Leaving it on could result in both chassis and house batteries being dead!

[JaxDad]

heyobie wrote:
Thanks guys for all the help and education and support. I'm smarter than I was and Crush (that's my RVs name) is now better off.

After I put it all back together I got it working as designed. Victory. I just need to add a toggle switch so I can control when it charges the house.

I’m not sure why you’re concerned about charging it or not, the chassis battery gets ‘charging’ anytime the engine is running, why not the house battery too?

Every other m/h out there works this way and have for many decades now.

To me a switch just invites the possibility of accidentally leaving it off and not having a charged battery.

[enblethen]

Battery connection link from Pianotuna

[pianotuna]

heyobie wrote:
Pianotuna,

Not sure what you mean by balanced manner?

This is what is balanced and best for twin twelve volt batteries.



As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

correctly interconnecting multiple twelve volt batteries

Others may say it doesn't matter--but unless there is a compelling reason to not optimize charging and discharging why not do it the best possible way?

[heyobie]

Pianotuna,

Not sure what you mean by balanced manner?

[pianotuna]

heyobie wrote:


I went to Sam's Club and got a second 12 volt marine/RV battery to match the one that I had first and I will be wiring them in parallel so that I can get ready for my big trip.

Be sure to wire the batteries in a balanced manner.

[heyobie]

Thanks guys for all the help and education and support. I'm smarter than I was and Crush (that's my RVs name) is now better off.

So I decided to test the solenoid now that I understand what is supposed to happen. So I gave the small post 12 volts and it worked just fine. I redid the wiring and cleaned all contacts and posts. There was some corrosion and bad wiring which caused the solenoid not to function. After I put it all back together I got it working as designed. Victory. I just need to add a toggle switch so I can control when it charges the house.

I went to Sam's Club and got a second 12 volt marine/RV battery to match the one that I had first and I will be wiring them in parallel so that I can get ready for my big trip.
While it is a 1988 it only has 40,000 miles on it of which I have put on 10,000. We are planning to go from Maryland to Northern Florida and cut across the Gulf Coast for about a month this winter. So I will be better able to handle the cold than I was with just 1 battery and no house charge as I drove.

Again, thanks for the help.

[pianotuna]

Much better to use a dc to DC charger. I have a 20 amp unit and love it.

[BarabooBob]

I had a 1988 Damon (built on a one ton Toyota chassis.) That unit had a solid state battery isolator from the factory. It worked great until it didn't work at all. I replaced it with a constant duty solanoid type isolator. It then worked great again.
The shortfall of my system was the 60 amp alternator. It could barely keep the chassis battery charged when the headlights were turned on. A conversion to a 150 amp alt gave better charging but took extra power to spin the alt, something that my 110 hp engine didn;t have an abundance of.

I forgot to say that from what I have heard, if you want to add a second battery to your coach, the batteries should be installed together as a pair. Adding a new battery to and old battery will give you two old batteries because the old will draw down your new much faster.

[enblethen]

In that era, there was no electronics operating the relay. It was controlled manually by rocker switch.