Battery Charging

[Romer1]

2000 Suncruiser 35U, does anyone know if the engine alternator charges my house batteries while driving?

[wolfe10]

YES assuming it is working as designed. Both house and chassis batteries are charged by the alternator.

[Romer1]

Thanks, thought it did,but wasn't sure.. Didn't see much of a change on the meters at the panel. Guess it has to be at more than idle.

[winnie32v]

Charging of the Coach Batteries does occur when the engine is running (any RPM) PROVIDING the CO (Continuous Operation) solenoid is functioning properly.

This solenoid is energized by a 12v current when the engine is running, solenoid contacts are closed and the charging current from the alternator is also directed to the Coach Batteries.

This can be easily checked by using a multimeter to check the voltage of the coach batteries, before and after starting.

It is not uncommon that the solenoid becomes oxidized and the contacts won't complete the charging circuit.

I have remover my solenoid and taken it apart to clean the contacts.
I have also purchased a new replacement solenoid that I keep for a quick replacement, if needed.

I have attached photos of the solenoid as it is attached in the motorhome as well as several to show the internal contacts of the unit.

Let us know how you make out.

[Romer1]

Originally Posted by winnie32v

Charging of the Coach Batteries does occur when the engine is running (any RPM) PROVIDING the CO (Continuous Operation) solenoid is functioning properly.

This solenoid is energized by a 12v current when the engine is running, solenoid contacts are closed and the charging current from the alternator is also directed to the Coach Batteries.

This can be easily checked by using a multimeter to check the voltage of the coach batteries, before and after starting.

It is not uncommon that the solenoid becomes oxidized and the contacts won't complete the charging circuit.

I have remover my solenoid and taken it apart to clean the contacts.
I have also purchased a new replacement solenoid that I keep for a quick replacement, if needed.

I have attached photos of the solenoid as it is attached in the motorhome as well as several to show the internal contacts of the unit.

Let us know how you make out.

Thanks, I'll check tomorrow, storage is closed today

[Romer1]

Originally Posted by winnie32v

Charging of the Coach Batteries does occur when the engine is running (any RPM) PROVIDING the CO (Continuous Operation) solenoid is functioning properly.

This solenoid is energized by a 12v current when the engine is running, solenoid contacts are closed and the charging current from the alternator is also directed to the Coach Batteries.

This can be easily checked by using a multimeter to check the voltage of the coach batteries, before and after starting.

It is not uncommon that the solenoid becomes oxidized and the contacts won't complete the charging circuit.

I have remover my solenoid and taken it apart to clean the contacts.
I have also purchased a new replacement solenoid that I keep for a quick replacement, if needed.

I have attached photos of the solenoid as it is attached in the motorhome as well as several to show the internal contacts of the unit.

Let us know how you make out.

Do you have the part no for the solenoid? I have an F53 also, just 1 year older. Assume solenoid is under the hood area, correct?
TIA

[cbeierl]

Originally Posted by Romer1

Do you have the part no for the solenoid? I have an F53 also, just 1 year older. Assume solenoid is under the hood area, correct?
TIA

Looking at the Chassis Wiring Installation diagram for your coach it appears the solenoid(s) are above and inboard of the batteries under your entry steps. You may find the Automotive Wiring Diagram helpful as well.

[winnie32v]

Do you have the part no for the solenoid? I have an F53 also, just 1 year older. Assume solenoid is under the hood area, correct?
TIA

As stated above, my solenoid is located behind the second entry step.
It is grounded via the attachment to a metal plate.
I have seen some units where this solenoid is located under the hood.

It is a 3-terminal unit because it is grounded to the metal plate via 2 installation bolts.
So, no extra grounding terminal is required (as IS with most Marine applications, 4-terminal).

This is a high-amp solenoid. There are many on eBay for a lot less than you would pay at a parts store. Look up Continuous duty 3 terminal solenoid and you will find several at the 150 - 200 amp range.
These are pretty simple devices. They operate by an electromagnet activated by 12v. Continuous 12v closes the contacts and the batteries are directly connected to the alternator charge system.

[Romer1]

Originally Posted by winnie32v

Do you have the part no for the solenoid? I have an F53 also, just 1 year older. Assume solenoid is under the hood area, correct?
TIA

As stated above, my solenoid is located behind the second entry step.
It is grounded via the attachment to a metal plate.
I have seen some units where this solenoid is located under the hood.

It is a 3-terminal unit because it is grounded to the metal plate via 2 installation bolts.
So, no extra grounding terminal is required (as IS with most Marine applications, 4-terminal).

This is a high-amp solenoid. There are many on eBay for a lot less than you would pay at a parts store. Look up Continuous duty 3 terminal solenoid and you will find several at the 150 - 200 amp range.
These are pretty simple devices. They operate by an electromagnet activated by 12v. Continuous 12v closes the contacts and the batteries are directly connected to the alternator charge system.

Just purchased this as a spare if needed
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

[winnie32v]

That's the one I would recommend.

[Romer1]

Discovered generator will charge house batteries, but alternator doesn't. Think I have a missing wire. Mechanic is going to check out while he has it later this week for annual pre-trip inspection.

[winnie32v]

I'd have to check the wireing diagrams.
I seem to recall that the gen charges through a different path.
Easy to troubleshoot the solenoid function.

Keep us informed.
Thanks

[iowagasman]

I bought a 12 volt meter and I check the motor home first then the house batteries to see at what vote they are. Then I start the motor home and check the starting battery to see that it is charging then the house batteries to see if they are charging at the same voltage. If everything is the same we are golden.

[twinboat]

The generator doesn't charge anything.

It sends 120 volt power to the converter/charger or inverter/ charger. That charger is connected to the house batteries and charges them.

On the other side, the engine alternator is connected to the chassis battery and only charges that.

The contiounus duty solenoid, talked about in the post, is called a isolation solenoid.

Its there to connect the chassis battery to the house battery, when the chassis battery is receiving a charge, sharing that charge with the house battery.

Many systems also use the same solenoid when the house batteries are charging, to share the charging with the chassis battery. That's called bi-directional charging.

Last but not least, the switch on your dash labled AUX, Emergency or Boost start also closes that solenoid, connecting all,of the batteries together to help weak ones start the engines.