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SJ-Chris

San Jose, Ca

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Posted: 03/22/21 03:06am Link  |  Quote  |  Print  |  Notify Moderator

coolmom42 wrote:


*Does the chassis alternator charge the house battery? If so, how well?



Almost every RV is set up to allow the chassis alternator to charge the house battery. (it's a beautiful thing that comes almost for free).

I have a 2015 Thor Majestic 28a...In my experience, the chassis alternator does a great job charging the house batteries. I have a battery monitor on my house battery bank. When the house batteries are at ~50%, I have seen my chassis alternator pumping 50+ amps into my house batteries when the engine is running (even just idling).

-Chris


San Jose, CA
Own two 2015 Thor Majestic 28a Class C RVs

enblethen

Moses Lake, WA

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Posted: 03/22/21 06:34am Link  |  Quote  |  Print  |  Notify Moderator

Large fuses like the 200 amp could feed a large inverter if equipped.
Others answers sound good!


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houstonstroker

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Posted: 03/22/21 08:08am Link  |  Quote  |  Print  |  Notify Moderator

Most of the Dynamax rigs on Freightliner M2 chassis, do allow for chassis batteries to be charged by the converter. It is done through a BIRD and relay. If you are plugged into shore power then coach batteries are priority until they are charged. At this point the relay will close and allow the chassis batteries to be charged. It works in reverse when the engine is running.


2016 Dynamax Force HD Super C

DrewE

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Posted: 03/22/21 08:35am Link  |  Quote  |  Print  |  Notify Moderator

Based on my 1998 Coachmen Santara...I'm guessing your motorhome is similar.

coolmom42 wrote:

*Does the generator have its own starting battery? If so, how is this battery charged? Or does the generator crank off the chassis battery? (I'm assuming it doesn't crank off the house battery, as that would kind of defeat the point of having a generator.)


The generator starts off the house battery in my motorhome. It's not as silly as it sounds because the generator requires some 12V power while it's running, and if that's from the house system it comes from the converter rather than running down the chassis battery. The generator doesn't have any 12V charger built-in to it directly. (I think a 12V charger is an option that can be had with the Onan generator, but it's very rare in RV applications since you need the converter anyway.)

coolmom42 wrote:

*Does the generator charge the chassis battery?


No, not as from the factory; neither does the converter when plugged into shore power, since it's the same thing. A Trik-L-Start is one way to get this, or you can just connect up and plug in a small battery charger.

coolmom42 wrote:

*Does the chassis alternator charge the house battery? If so, how well?


Yes, and on mine pretty well--at least well enough to have a nicely recharged house battery after a day of driving.

coolmom42 wrote:

*Does the battery isolator switch completely isolate the house battery and chassis battery from each other?


The battery isolator is likely a solenoid, which is active whenever the engine is running or the emergency start switch is pressed. When not active, the two batteries are entirely separated and isolated. When active, they're tied together.

Do not confuse this with the house battery disconnect switch, which is a separate thing that disconnects most of the house circuits from the house battery. Exactly what is disconnected varies from RV to RV; on mine, as built by the factory, the disconnect is between the house battery and the 12V distribution panel, and the only things that are not disconnected are the generator (presumably because the current required when starting is more than is wise to put through the disconnect switch), the connection to the battery isolator, the converter, the dash radio memory line, and the power for the (manually-controlled) entry step.

coolmom42 wrote:

*Does the converter charge the chassis battery when the RV is plugged into shore power?


No

coolmom42 wrote:

*On the side of the engine compartment, there is a 200 amp fuse. What is this for?


If it's connected to the chassis battery more or less directly, it's probably to protect the wire used for charging the house battery and for the emergency start. The other end of the wire connects to the battery isolator solenoid, which in my case is next to the house battery, along with it's main fuse and a few self-resetting circuit breakers and so forth.





CharlesinGA

South of Atlanta, Georgia

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Posted: 03/22/21 10:14am Link  |  Quote  |  Print  |  Notify Moderator

Links to various models of the Trik L Start. These products allow the coach/house batteries to maintain a charge on the chassis/engine battery. It will not allow current to flow from the chassis to the coach, only from the coach to the chassis, it limits the amount of current to a max of 5 or 10 amps depending on the model, and has low voltage cutoffs that will prevent the coach batteries from getting low if they are not being recharged by the converter (via generator or shore power) or by solar.

If you have a bus or large diesel pusher type MH that has a large battery bank, then the 15 amp Amp-L-Start would be the best choice.

If you have a Class C and want a little more power output than the standard 5 amp "Ultra" Trik-L-Start, then the 10 amp "Mega" would be a good choice.

For a typical Class C the 5 amp "Ultra" version would be a good choice if you want the Chassis battery to remain topped off in storage and have shore power in storage or solar.

By using the Trik L Start, the chassis/engine battery will be fully charged while you are parked and receiving solar or shore/generator power.

None of these will overcharge the chassis/engine battery, they will only provide whatever current is needed to keep the battery topped off.

https://www.rvupgradestore.com/Ultra-Trik-L-Start-p/tls-oem.htm

10 amp Mega Trik L Start info flyer

Excellent flyer with FAQ and diagrams an........e Mega but the info is the same for all.

Home page for LSL Products which also lists the Amp-L-Start which is 15 amps.

Charles

* This post was edited 03/22/21 10:20am by CharlesinGA *


'03 Ram 2500 CTD, 5.9HO six speed std cab long bed Leer top and 2008 Bigfoot 25B21RB.. previously 2008 Thor/Dutchman Freedom Spirit 180. SOLD - 2007 Winnebago View 23H Motorhome.

CharlesinGA

South of Atlanta, Georgia

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Posted: 03/22/21 10:27am Link  |  Quote  |  Print  |  Notify Moderator

Generally the MH manufacturers will not take power from the chassis/engine battery for generator starting as they do not want to risk running down the battery and leaving you stranded.

The manufacturers do however take power from the chassis/engine battery for the slide system and the retractable steps, as they do not want to risk you being stranded by not being able to retract either of these. If you have a slide, it is a very good idea to run the engine while you are operating the slide so you have higher voltage and additional amperage available to operate it. My Winnebago View recommended this in the manual.

Charles

time2roll

Southern California

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Posted: 03/22/21 10:42am Link  |  Quote  |  Print  |  Notify Moderator

bobndot wrote:

At a dealer ? Why can't dealer answer your questions ?
Even if they do answer some questions... nothing wrong with verifying here. Dealer is not always correct or complete.

If you have an issue to address there is often a fairly simple solution to get the electrical system to operate better or to what your needs are. Check in here with these questions too.


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klutchdust

Orange, California

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Posted: 03/22/21 10:42am Link  |  Quote  |  Print  |  Notify Moderator

When my coach was on ground power the chassis battery would be dead in 2 weeks from all the parasitic drains. I plugged a battery monitor into the 120 wall outlet that were hot from the ground power and plugged the other end into the accessory port on the dashboard. Problem solved.
I like Charles recommendation when using your slides. Mine required that .

bobndot

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Posted: 03/22/21 11:00am Link  |  Quote  |  Print  |  Notify Moderator

Quote:

Dealer is not always correct


Same applies here. [emoticon]

time2roll

Southern California

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Posted: 03/22/21 11:05am Link  |  Quote  |  Print  |  Notify Moderator

bobndot wrote:

Quote:

Dealer is not always correct
Same applies here. [emoticon]
Yes and will usually soon get corrected.
Dealer's word just stands in the darkness.

Answers here also have no profit motive.

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