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Alternator limitations?

I was looking at the schematics on my unit and I noticed the house heaters are on the 12V system.  I'd never really used them and I had just assumed they were part of the 120V system.  With that in mind, my understanding is I could be rolling down the road with house heaters running off the batteries and the alternator charing the batteries?  Maybe the more accurate question is can the OEM specified alternator handle the ENTIRE 12V house and chassis system with no issues?
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Alternator limitations?

Reply #1 –
Benjie,
Are you talking about the propane furnaces?  If so, I believe the coach batteries in good state should be able to handle the load with the alternator as the battery charger's source for charge.  Can you tell what the amp rating is for your alternator?
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: Alternator limitations?

Reply #2 –
Benjie,

Yes, of course you can.  That's the way the coach is designed to be used.

Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Alternator limitations?

Reply #3 –
Peter, I'm not exactly sure.  It's supposed to be a 190A alternator according the spec sheet, but was recently changed right before I took possession of it.  I'm hoping its at least the same 190A if not more, but plan on checking next time I'm at the coach.

Quote from: Peter & Beth –
Benjie,
Are you talking about the propane furnaces?  If so, I believe the coach batteries in good state should be able to handle the load with the alternator as the battery charger's source for charge.  Can you tell what the amp rating is for your alternator?
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Alternator limitations?

Reply #4 –
For us, the short answer is, "Yes, the alternator will keep up with 12VDC demand." We normally only use the generator while traveling if we need to run the roof air conditioners. We will even use a toaster oven or microwave oven running from the inverter to heat lunch or snacks on the road. The use is brief.

We travel in cold weather with the two house furnaces running. The 12VDC is for the fans and controls. The heat comes from burning propane. It is not a large electrical load.

We recently spent the night in a casino parking lot with no hookups. Overnight temperatures got down to about 25F. With the inverter turned off and conservative use of lighting, we used about 110 amp-hours from the house batteries. We had thermostats set at about 68F. The 110 amp-hours draw down is a reasonable load for our three 8D batteries. We used the generator in the morning to charge batteries, run the coffee pot, run the waffle iron, and run the block heater for a couple of hours before we started the "big" engine.

Our experience has only been a couple of years, but we have had success operating this way. We have traveled about half of our 21K miles in the U295 running in cold weather with heaters on. So far, it has worked well for us.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Alternator limitations?

Reply #5 –
Thanks Brett.  I figured as much, but nice to have someone confirm.

Quote from: amos.harrison –
Benjie,

Yes, of course you can.  That's the way the coach is designed to be used.
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Alternator limitations?

Reply #6 –
Awesome! Thanks for sharing your experience as we plan on running up to IL to my folks house next Xmas!
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Alternator limitations?

Reply #7 –
The house heaters (fore and aft furnaces) only draw from the 12vdc system for the fans; the heat comes from propane. If you keep the heat down to 60F the batteries will last at least a weekend (at least on our coach). Cheap to wear sweaters and thick socks and slippers.

The alternator will easily handle the fans if the engine is running... we only run the aft furnace in temps down to about 20F and use the cab heater for the front living area. This has always kept us comfortable. Best of all, the coach is warm when we get to where we want to stay for the night (unlike a trailer).

Craig
1993 U225 36' Unihome GV with PACBRAKE exhaust retarder, Banks Stinger and Solar Panels.
Toad: 1999 Jeep Wrangler 2-door soft-top.

"No one has ever had to evacuate a city because the solar panels broke."

Re: Alternator limitations?

Reply #8 –
As we live mostly off of solar (and occasionally wind power) we do not like running our furnace due to the amperage it draws and the noise it makes.  We won't talk about the burst of cold air that comes when it turns on..........

We currently use a Mr. Heater Tough Buddy (4/9/18K btu) up front on the center dash table and an Olympian Catalytic (1220/3000 btu) back by the dinette, and both units are piped in from the main propane tank.  The Mr. Heater has a fan that we can use that works off of the 12 volt battery system if we have the heater on high.
Saves a lot of work for our expensive Gel batteries.  Both are nice and quiet and very little battery energy use.  Easier on the alternator too..........
Regards,
JON TWORK KB8RSA
Full Time RVer (10+ Years) & Dedicated Boondocker
Retired, Unemployed, Homeless Transients
1996 Foretravel U270-36 w/24' Timberwolf Trailer
I firmly believe that tomorrow holds the possibility for new technologies, astounding discoveries, and a reprieve from my remaining obligations.
Welcome to WeRV2 (Under Construction)
Find Jon: Via Satellite Tracker Datastorm Users
The Second Amendment is in place in case they ignore the others.

Re: Alternator limitations?

Reply #9 –
Quote from: Jon Twork –

We currently use a Mr. Heater Tough Buddy (4/9/18K btu) up front on the center dash table and an Olympian Catalytic (1220/3000 btu) back by the dinette, and both units are piped in from the main propane tank.  The Mr. Heater has a fan that we can use that works off of the 12 volt battery system if we have the heater on high.

I can sing the praises of catalytic heaters too. There are some precautions you have to take with them but they are extremely good heaters. They do not, however, heat the basement or the holding tanks so if temperatures are freezing both day and night for very long you could expect problems.

We also have a Mr. Buddy for the ice rink. Nice to sit next to it and warm up. :)

Craig
1993 U225 36' Unihome GV with PACBRAKE exhaust retarder, Banks Stinger and Solar Panels.
Toad: 1999 Jeep Wrangler 2-door soft-top.

"No one has ever had to evacuate a city because the solar panels broke."

Re: Alternator limitations?

Reply #10 –
I know a lot of people with RVs that have gone to unvented heaters. They are almost 100% efficient, use no electricity and make no noise. HF sells a couple of models that will heat the whole RV for about $100. They can cut the propane usage by over 50%.

Couple of things to remember. They are not approved for RVs and are 49 state legal so you can't order one if you live in California. There are good reasons for this. They do have low oxygen and CO sensors but no guarantee that they will work and turn off the heater. Have to remember to crack a window.

If they have ANY kind of yellow flame visible, they are producing carbon monoxide and need to be adjusted ASAP. Most companies make radiant as well as convection models. In an RV with everything in close proximity, the convection model would probably be safer. A wall mount would more secure than having one that could move around.

There are several good articles online about the reliability of the sensors. A lot of folks have not awakened in the morning using them so be careful.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Alternator limitations?

Reply #11 –
Quote from: Pierce & Gaylie Stewart –
There are several good articles online about the reliability of the sensors. A lot of folks have not awakened in the morning using them so be careful.

We have a wall-mounted catalytic heater (Olympian) in the little 21-foot Streamline Princess (which may be for sale... if anyone is interested) that will take the inside temp from 40F to 70F in 15 minutes. We have used it a lot but never used it over night because of the risk of not waking up in the morning.

Goose down sleeping bags are much better!!

Craig
1993 U225 36' Unihome GV with PACBRAKE exhaust retarder, Banks Stinger and Solar Panels.
Toad: 1999 Jeep Wrangler 2-door soft-top.

"No one has ever had to evacuate a city because the solar panels broke."

Re: Alternator limitations?

Reply #12 –
Quote from: Jon Twork –


We currently use a Mr. Heater Tough Buddy (4/9/18K btu) up front on the center dash table and an Olympian Catalytic (1220/3000 btu) back by the dinette, and both units are piped in from the main propane tank.  The Mr. Heater has a fan that we can use that works off of the 12 volt battery system if we have the heater on high.

JON, How did you pipe in from the propane tank? Did you drill a hole in the floor or wall, and if so, where did you do that?

Thanks, Susan
Susan
Chimayo, NM
1990 U280 36'

Re: Alternator limitations?

Reply #13 –
Quote from: Susan –
JON, How did you pipe in from the propane tank? Did you drill a hole in the floor or wall, and if so, where did you do that?

Thanks, Susan


We got a ways off the "alternator" subject but...

I put a "T" in the line down in the compartment and also installed a quick connect for a BBQ. Line comes up through the floor to the heater.

The radiant type of heater is great for sitting in front of but has a much higher risk of fire if anything combustible is put in front of it.

CO is dangerous at any elevation. High altitude along with any type of heart condition or C.O.P.D. and Carbon Monoxide is an especially risky combination. In fresh air, it still takes 4-5 hours to reduce the CO level by 50% and in case of a heart attack, pure oxygen is not able to be assimilated by the red blood cells. A quote: "Carbon monoxide binds to hemoglobin 200 times more tightly than oxygen. It is quite likely that the red cell with carbon monoxide bound hemoglobin will die out before it loses carbon monoxide."  Since red blood cells live about 120 days, it can be a long time until your blood has returned 100% to normal.

Here is an inexpensive investment in detectors. Many more can be found on ebay. BRK CO250LB Carbon Monoxide Detector, 9V Battery Powered & Electromechanical |

Photos below of our installation.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Alternator limitations?

Reply #14 –
For Carbon Monoxide Detector I much prefer one with digital readout. I want to know when there is any carbon monoxide around not just when it's reached unsafe levels. They are more expensive though.

Atwood Co Carbon Monoxide Gas Alarm Detector 32519 | eBay

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Alternator limitations?

Reply #15 –
Ken,

I like the digital read out. How is this for an economical alternative? $9.30 delivered. Actually, both are made in China. New LCD Co Carbon Monoxide Poisoning Gas Sensor Warning Alarm Detector Tester | Mine should be here in a couple of weeks so will do a review and bring it to Quartzite.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Alternator limitations?

Reply #16 –
Quote from: Pierce & Gaylie Stewart –
We got a ways off the "alternator" subject but...

I put a "T" in the line down in the compartment and also installed a quick connect for a BBQ. Line comes up through the floor to the heater.

The radiant type of heater is great for sitting in front of but has a much higher risk of fire if anything combustible is put in front of it.

CO is dangerous at any elevation. High altitude along with any type of heart condition or C.O.P.D. and Carbon Monoxide is an especially risky combination. In fresh air, it still takes 4-5 hours to reduce the CO level by 50% and in case of a heart attack, pure oxygen is not able to be assimilated by the red blood cells. A quote: "Carbon monoxide binds to hemoglobin 200 times more tightly than oxygen. It is quite likely that the red cell with carbon monoxide bound hemoglobin will die out before it loses carbon monoxide."  Since red blood cells live about 120 days, it can be a long time until your blood has returned 100% to normal.

Here is an inexpensive investment in detectors. Many more can be found on ebay. BRK CO250LB Carbon Monoxide Detector, 9V Battery Powered & Electromechanical |

Photos below of our installation.

Pierce
Thanks, Pierce and Gaylie for showing how you did this.

My propane tank has an after market drawer put in above the propane tank which has a very metal frame obscuring the way  of drilling up through the floor... So, I drilled sideways through the wall into the stairwell (my motorhome has the door midway), attached to an already there quick attachment like for your barbecue and brought the hose snug against the stairwell wall and along the floor. Should do the trick.

Thanks again,
Susan
Susan
Chimayo, NM
1990 U280 36'