Community Forums

SeabLobo · 06-05-2023, 08:02 AM

First year with Class A motorhome - do the house batteries charge from the alternator while running on the road?

wolfe10 · 06-05-2023, 08:08 AM

In a word, YES.

But giving us more info on what chassis and coach you have will allow us to help with diagnosis of how YOUR system works.

SeabLobo · 06-05-2023, 08:14 AM

Quote:

Originally Posted by wolfe10

In a word, YES.

But giving us more info on what chassis and coach you have will allow us to help with diagnosis of how YOUR system works.

2004 Pace Arrow, Workhorse 8.1

**Lt Dan** · 06-05-2023, 08:24 AM

Simple way to test is to check the voltage on the house batteries with the engine running to see if they are above 13 volts. You should have a battery merge solenoid that allows the alternator to charge the house batteries, but the one on our '06 Itasca had failed and had to be replaced.

Dodge Guy · 06-05-2023, 02:42 PM

Yes! If it doesn’t, something is wrong.

SJ-Chris · 06-06-2023, 01:40 AM

It is a common problem to have the solenoid fail after several years. The good news is that this is an inexpensive part and is easy to change.

-Chris

Ludo · 06-06-2023, 02:38 AM

Normally the alternator should do the job, but if you have sufficient solar panels on your roof it's not really necessary. The sun doesn't care if your RV is standing or moving.

MrMark52 · 06-06-2023, 04:05 AM

Hmmmm - we’ve had 2 coaches and neither had circuitry that let the engine alternator charge the house batteries, or the converter to charge the chassis batteries.

Both coaches listed below - neither are/were bottom line coaches missing the extra frills.

Had to add an IntelliTec B.I.R.D. to both coaches.

twinboat · 06-06-2023, 05:11 AM

Quote:

Originally Posted by MrMark52

Hmmmm - we’ve had 2 coaches and neither had circuitry that let the engine alternator charge the house batteries, or the converter to charge the chassis batteries.

Both coaches listed below - neither are/were bottom line coaches missing the extra frills.

Had to add an IntelliTec B.I.R.D. to both coaches.

They had chessis to house charging, yours wasn't working.

House to chassis wasn't as common but many DPs had it.

Dutch Star Don · 06-06-2023, 11:47 AM

Your year model was right on the cusp of some changes in charging systems. If working properly, your coach will charge the house batteries while driving. As you drive, it will sense which batteries need charging and switch back and forth between house and chassis.

Here is where your coach may not charge everything. When parked and on shore power, your charger will charge the house batteries. However, it may not charge your chassis battery(ies). This can come as a big surprise after camping/parking in one place for a couple of weeks, while hooked to shore power, and find out the engine battery went dead.

It was around 2003 - 2006 (rough estimate) that many companies began adding systems that charged both battery banks while on shore power.

You'll need to do some investigation to see if your coach charges the chassis battery and if not, there are a couple different companies offering a simple product that will combine charging.

twinboat · 06-06-2023, 02:10 PM

Quote:

Originally Posted by Dutch Star Don

Your year model was right on the cusp of some changes in charging systems. If working properly, your coach will charge the house batteries while driving. As you drive, it will sense which batteries need charging and switch back and forth between house and chassis.

.

Where are you getting your info ?

What manufacture would switch the alternator output from one battery bank to another. The engine and chassis component rely on a steady voltage to funtion.

Pre 2002 or so, diode isolators were used to split the alternator output to BOTH battery banks. The chassis bank, being the critical one for stable voltage, was the one that controlled the alternators regulator.

Many DPs also used Lambert LE-415 battery maintainers to maintain the chassis battery while on shore power, back in the 90s.

When diode isolators went out of fashion, because they never really charged the house batteries fully, solenoids cabled between the chassis batteries and house batteries was adopted.
The alternator was connected to the chassis battery so it could maintain proper voltage for the computer engine controls.

Charging of the house batteries was controlled in a number of ways. The solenoid was sometimes opened and closed by key on, oil pressure of the engine, and an assortment of logic controllers, including the BIRD.

If you have a different system, that switchs output, show us.

wolfe10 · 06-06-2023, 02:15 PM

And, for those who are KISS Theory, there is an easy solution to alternator charging of the battery banks. It also doesn't require a DUVAC alternator since there is no voltage drop (assuming correct wire size):

Simple marine battery switch with OFF and ON only.

Alternator B+ and chassis battery to one lug.

House battery to the other lug.

Switch off, alternator charges only chassis battery.

Switch on alternator charges both battery banks.

Here is one: https://www.perko.com/catalog/batter...onnect_switch/

Flyer15015 · 06-06-2023, 02:32 PM

OP,
You and I have the same coach.
Mine charges the house batteries just fine, going down the road or plugged in.

Mike in Colorado

Dutch Star Don · 06-08-2023, 10:57 AM

Quote:

Originally Posted by twinboat

Where are you getting your info ?

What manufacture would switch the alternator output from one battery bank to another. The engine and chassis component rely on a steady voltage to funtion.

Pre 2002 or so, diode isolators were used to split the alternator output to BOTH battery banks. The chassis bank, being the critical one for stable voltage, was the one that controlled the alternators regulator.

Many DPs also used Lambert LE-415 battery maintainers to maintain the chassis battery while on shore power, back in the 90s.

When diode isolators went out of fashion, because they never really charged the house batteries fully, solenoids cabled between the chassis batteries and house batteries was adopted.
The alternator was connected to the chassis battery so it could maintain proper voltage for the computer engine controls.

Charging of the house batteries was controlled in a number of ways. The solenoid was sometimes opened and closed by key on, oil pressure of the engine, and an assortment of logic controllers, including the BIRD.

If you have a different system, that switchs output, show us.

This can go on forever if your intent is to attack every post I make, kind of childish! Do you think everyone out there understands how a B.I.R.D. works. When someone asks a simple question and not that knowledgeable, they need a simple answer. The engine alternator in the overall picture does charge both battery banks when going down the road. Are you saying they don't! In 2005 my Diplomat did not have a way to charge chassis batteries when the coach was parked and that had to be added. The OP needed to know that info.