2018 Forza38w Inverter Settings; Parked, Driving, with Shore Power

MikeOwens · 04-11-2019, 10:46 AM

I have a 2018 Forza38w I got a couple of months ago. This is my 5th RV in 20+ years, but my first motor-home. I drove my motor-home up north and when I got there, there was not enough juice in my chassis batteries to open the slides. I had to hit the "Boost Button" to pull the power from the coach. I am thinking it is operator error on the settings on the panel, but I was looking for coaching in my 3 scenarios:

1. When I am at home and I have the coach plugged into 110v power
2. When I am driving to a location
3. When I am at an RV park and on Shore power

Scenario #1 - At Home
I have the 110v power connected, with house batteries main "OFF", but the Chasis main "ON", so it will charge. Once I turn the fridge on (Prepping for a trip), I have to have the Coach main "ON".
Questions:

Since I am connected to 110v power, I have the inverter manual knob under the coach always on?
Do I leave the "Inverter" computer panel on "Float Charger" vs. "Pass Through"?

Scenario #2 - Driving to an RV Park
I start up the coach and let it run to bring all the air and main functions up and running. I want to make sure the batteries for the coach and chassis are being charged as I drive, I want to make sure there is power to the fridge, which seems to be 110v vs 12v and propane like my trailers in the past.
Questions:

What is the right setting for the computer control panel? If I don't have it "Pass Through", I don't have a light in the fridge and I don't think the fridge compressor is running.
Shouldn't the engine running enable power for the fridge and charge the house and chassis batteries?
Is there a potential that my inverter is bad?

Scenario #3 - Shore power at the RV Park

When I get to the park, I leave the motor running, so I can auto-level, then use the power from the motor to move the slides out. This is where I had the challenge, since for some reason, the chassis batteries didn't have enough juice after driving with the motor on for 6 hours:

Questions:

I assume I just have the inverter setting on the computer control panel set to "Float Charge" to make sure the batteries are charged for when I leave

Sorry for the details, but I am trying to determine if there is something wrong with a component of my new motor home or just "Operator Error".

al1florida · 04-12-2019, 03:33 PM

I don't have the MH you have, so can't give first hand info.

Scenario #1 - At Home
I have the 110v power connected, with house batteries main "OFF", but the Chasis main "ON", so it will charge.

Winnebago has used "Trickle-Charger" on other, older DP (Diesel Pushers) to keep the chassis battery charged. The Trickle-Charger uses the higher voltage from the house batteries(kept charged by shore power) to charge the chassis battery charged. Having the house main off probably won't keep the house battery charged, so you won't keep the chassis battery charged.

Scenario #2 & #3:
Doesn't your power monitor panel show the actual voltage of your house and chassis battery? If not you need a multi meter to measure the voltage of both sets of batteries. Giving us the battery voltages when you are having the problems you listed would really help with trouble shooting. Also checking the battery voltages may help you learn how the different systems work.

Is there any info in your owners manual to help determine what the different settings should be?

When your inverter is in the float charge mode you should see about 13.4V or a little higher at the house batteries. If not then your inverter is not charging your house batteries and may be bad. Again giving us the voltages at the time the problem is happening would really help.

al1florida · 04-13-2019, 04:50 AM

Quote:

Originally Posted by MikeOwens

I have a 2018 Forza38w I got a couple of months ago. This is my 5th RV in 20+ years, but my first motor-home. I drove my motor-home up north and when I got there, there was not enough juice in my chassis batteries to open the slides. I had to hit the "Boost Button" to pull the power from the coach. I am thinking it is operator error on the settings on the panel, but I was looking for coaching in my 3 scenarios:

1. When I am at home and I have the coach plugged into 110v power
2. When I am driving to a location
3. When I am at an RV park and on Shore power

Scenario #1 - At Home
I have the 110v power connected, with house batteries main "OFF", but the Chasis main "ON", so it will charge. Once I turn the fridge on (Prepping for a trip), I have to have the Coach main "ON".
Questions:

Since I am connected to 110v power, I have the inverter manual knob under the coach always on?
Do I leave the "Inverter" computer panel on "Float Charger" vs. "Pass Through"?

Scenario #2 - Driving to an RV Park
I start up the coach and let it run to bring all the air and main functions up and running. I want to make sure the batteries for the coach and chassis are being charged as I drive, I want to make sure there is power to the fridge, which seems to be 110v vs 12v and propane like my trailers in the past.
Questions:

What is the right setting for the computer control panel? If I don't have it "Pass Through", I don't have a light in the fridge and I don't think the fridge compressor is running.
Shouldn't the engine running enable power for the fridge and charge the house and chassis batteries?
Is there a potential that my inverter is bad?

Scenario #3 - Shore power at the RV Park

When I get to the park, I leave the motor running, so I can auto-level, then use the power from the motor to move the slides out. This is where I had the challenge, since for some reason, the chassis batteries didn't have enough juice after driving with the motor on for 6 hours:

Questions:

I assume I just have the inverter setting on the computer control panel set to "Float Charge" to make sure the batteries are charged for when I leave

Sorry for the details, but I am trying to determine if there is something wrong with a component of my new motor home or just "Operator Error".

No reason to be sorry about the details, details are most helpful.

Looking at the Winnebago brochure for your MH, I see you DO have a residential fridge which would only work off of 120V. So for your fridge to work when you are not on shore power or generator you will have to have the inverter on.

Also from the brochure, here are the electrical systems:
Electrical System
Service Center cable TV input, 50-amp power
cord, shoreline/generator automatic changeover
switch, portable satellite hookup
2,000-watt inverter/charger w/remote panel
with coach battery disconnect switch
6,000-watt Cummins Onan® generator
Auxiliary start circuit
AC/DC electrical distribution system
4 deep-cycle Group 31 Marine/RV batteries
Battery disconnect system (coach and chassis)
PowerLine® Energy Management System
Automatic dual-battery charge control
Automatic generator start system

I am guessing that when you stated "Since I am connected to 110v power, I have the inverter manual knob under the coach always on?"
You are referring to the Inverter coach battery disconnect switch I highlighted above. This appears to disconnect the inverter from the house batteries and must be on for the inverter/charger to operate. I would always leave this in the on or connected setting unless you are going to store the RV for weeks or months.

When you use the following terms:
-- Inverter" computer panel
-- inverter setting on the computer control panel set to "Float Charge"
I assume you are referring to the "remote control panel" for the inverter/charger.
It would be unusual for an inverter to have an actual manual setting for "float charging". Usually there is a on/off setting for the charge function. If the house batteries are somewhat discharged you would see something like "Bulk" charging, followed by "Absorb" charging and when the batteries are close to being full, it switches to "Float" charging. So if the remote is showing float charging you batteries should be full or close to full charge.
Yes, you would normally leave your inverter on "charge" when on shore power or generator.

You write "What is the right setting for the computer control panel? If I don't have it "Pass Through", I don't have a light in the fridge and I don't think the fridge compressor is running."
Is this "pass through" setting on the inverter remote panel? I have not seen that term used on an inverter. There should be info in the owners manual to define that setting. NORMALLY an inverter "passes through" 120V when shore power or generator power is present. If shore/generator power is NOT present then as long as the inverter is "on" it would supply 120V (until the battery voltage drops to low) to the 120V circuits connected to the inverter, such as the fridge, microwave and most 120V outlets (but not the air conditioner & elect side of the water heater).
Since the light in the fridge doesn't come on until you select "pass through" I doubt the fridge is working unless you have the pass through setting selected. It is not clear if you are on shore power or not when using this setting.
BTW giving us the make and model of your inverter would really help. There should be online owner/operations manuals available.

Yes, the engine should keep the house battery and chassis battery charged when driving. That would be the function of the "Automatic dual-battery charge control" I bolded in the feature listing. That is probably a "Trik-L-Start" module mounted in the compartment at the front of the RV above the generator. Something like this: https://amsolar.com/rv-battery-accessories/98-trikl

Your RV has the "PowerLine® Energy Management System". There should be a switch on there to show the house and chassis battery voltages. Use the switch to show and record the house battery and chassis battery voltages. Now start the engine and see if you see charging voltages at both the chassis battery and house battery. You should see voltages in the upper 13's up to the mid 14's (volts that is). If not then something isn't working.
Additionally the chassis and house battery voltages are very important to know when the jacks and slides won't work. Both when the engine is running and not running.

Please come back with questions for anything that doesn't make sense in what I wrote above.

Whew, that was a full hour of research and writing.

khocke · 04-13-2019, 07:11 PM

With regard only to the non-opening slides part of your posting, your engine should be running when operating the slides (and jacks). This is what my dealer instructed during my PDI.

Journey39n · 04-28-2019, 06:25 PM

My coach, a forerunner to the Forza, is similar to yours.

However, a few main differences. First, the manual says to keep the engine running while leveling and extending/retracting slides. Those two functions do run off the chassis batteries. And except when I had an alternator going bad, they were always fully charged after any trip.

So, if your chassis batteries (and coach batteries too) are not fully charged after driving on a trip, do check the output of your alternator, a place to start.

2nd, I don't have a residential refrigerator, and keep my inverter shut off until I know I am going to need it. It runs off the coach batteries, with a pass-through if it senses 120v is supplied by shore or generator. You would leave yours on, all the time, to keep power to that residential refrigerator, if you aren't plugged into shore power or running the generator. When you drive, your alternator should be charging both sets of batteries, so no loss of voltage will be apparent at the end of the trip, even using the inverter to power that refrigerator. If they are low on voltage, the alternator, or batteries, or both could be at fault.

3rd, my converter supplies 12v to all coach functions when we are using shore or generator power. But when my coach batteries nearly died after 6 years of use, all sorts of strange things seemed to be happening, as by design, it shuts off periodically to cool a bit. That really affected all the 12v controls throughout the coach. Replaced the batteries, and all went back to normal.

As a general thing to try, when odd things seem to happen with the electrical systems. Use the disconnect switch to turn off both chassis and coach 12v power. Wait a minute, and switch them back on. All the various controls have computer chips in them, and once in a while, a reboot solves lots of odd happenings.