Shore power not charging chassis battery

[wheats1040]

Have 04 Fleetwood Revolution 40'. Cummins, freightliner. Shore power not charging chassis batt. When driving house batt.not charging. Any suggestions?

[krivanj]

Your solenoid is not closing. It connects the house to the chassis batteries if the voltage rises past 13.4 I think.

[Ron & Peri]

Search for BIRD, B.I.R.D. or Battery Isolation Relay

[twinboat]

That isolation solenoid your looking for is also used as the boost or emergency start solenoid.

Have someone push the button on and off while you listen for it clunk. They usually clunk on and off but don't make contact inside.

[Topworth]

Good afternoon, I don’t remember having the issue with house batteries not charging but my chassis batteries weren’t charging on shore power and many folks said that the system that was supposed to handle it was poorly built. This was the most common answer and I’ve not had any issues since installing it. Good luck.

[PCarnathan]

We have a 2009 Mandalay 43A with four huge AGM batteries for the coach and two smaller AGM batteries for the chassis. I noticed my chassis batteries weren't charging when plugged in. It turns out the coach batteries are "first in line" to be charged. They're so big that they spend a lot of time charging and sometimes the chassis batteries don't get charged. Simple fix? I ran a Battery Tender to the chassis batteries and now they're always ready to go.

From Amazon:

Battery Tender 022-0165-DL-WH 12-Volt 2-Bank Battery Management System

Pat in Menifee, CA
Temporarily full-timing while the new house is being built

[twinboat]

Before suggesting re-designing his isolation system with add-ons, we should be helping fix the the system he has.

The fact that his engine charging system is not charging the house batteries is a big clue that something is wrong with the installed system.

In hundreds, maybe thousands, of cases on this forum, the isolation solenoid is the issue, causing failed bi-directional charging.

The add-on devices are to fix a single directional charging system. In that case the chassis system would still be charging the house batteries, if working.

[vsheetz]

Originally Posted by twinboat

Before suggesting re-designing his isolation system with add-ons, we should be helping fix the the system he has.

The fact that his engine charging system is not charging the house batteries is a big clue that something is wrong with the installed system.

In hundreds, maybe thousands, of cases on this forum, the isolation solenoid is the issue, causing failed bi-directional charging.

The add-on devices are to fix a single directional charging system. In that case the chassis system would still be charging the house batteries, if working.

Agree. Fix the problem at hand first.

[RKins]

I agree with "don't invent a solution".
Most coaches have a built in monitoring and charge switching system (some may have proprietary systems). Usually this is made by Intellitec.

In your electrical bay (where the power cord is) there might be several large solenoids that are used to control the voltage going places and there is a Bi-directional relay delayed (BIRD) and it's job is to monitor the charging system by monitoring the voltage on the house batteries. If it see's a charging voltage (13.3+V) it will send out a voltage to activate a big relay that combines both banks so they both charge.

[wheats1040]

We were aware of that. Could hear it couldn't find it. Finally determined its behind the BCC. Drove us nuts looking for it.

[Gary RVRoamer]

If you have a BCC, that is the controlling logic for the solenoid and it could be the root cause. There is logic in the BCC to determine when the solenoid should be closed or open. However, your symptoms sound as though the solenoid has simply quit working.

[krudawg]

Originally Posted by wheats1040

Have 04 Fleetwood Revolution 40'. Cummins, freightliner. Shore power not charging chassis batt. When driving house batt.not charging. Any suggestions?

Had the exact problem on my last trip. I called Magnum Inverter Tech Rep who had me run a couple of checks. He determined that that was NO power on the input side. I was shocked because I hooked it up and like I always do, flip the power CB's to "ON". At least I thought it was on but in reality, the CB's were already "ON" so I had turned it off. I had got into a habit of flipping the CB's because most people turn them off before unplugging their rig. NOW, I actually look at the CB's and find that 98% of them are turned off by the previous tenant before they disconnect their rigs but the other 2% just unplug

[Reacher]

Recreational vehicles, or RVs, are equipped with battery isolators, which must function both when the engine is operating and when it is not.

RV battery isolators intelligently manage the charge and discharge of both chassis and coach batteries. If properly functioning, the device isolates one set of battery-and-equipment circuits from the other set of battery-and-equipment circuits. It must effectively act as a non-return valve for electricity, allowing current to pass in one direction but not the other.

An RV battery isolator may be cylindrical or flat and covered in fins like a heat sink, and will conventionally have three terminals.


Items you will need

• Wrench OR Screwdriver
• Pen and masking tape
• Voltage meter

Step 1

Follow the wires attached to the battery isolator and make a note of which terminal is attached to the chassis battery, the coach battery and the alternator.


Step 2

Check that terminal one is wired to the coach battery, and confirm with your operator's manual that this is correct.


Step 3

Check that terminal two is wired to the alternator, and confirm with your operator's manual that this is correct.


Step 4

Check that terminal three is wired to the chassis battery, and confirm with your operator's manual that this is correct.


Step 5

Use your wrench or screwdriver to disconnect the cables from the isolator terminals one at a time, wrapping each in white painter's tape and writing on it which terminal it came from.


Step 6

Set your voltage meter on "Diode Function" and test across the terminals. There should be continuity with the probes oriented one way, and no continuity with the probes reversed. If there is continuity shown for both orientations, or no continuity shown for both orientations, the isolator is faulty.


Reconnect the wires to the isolator if the isolator is functioning correctly. Isolators are not user serviceable components, so replace it if a fault is found.



Tips

• A properly operational battery isolator must fulfill three functions.
• It must firstly control charging of the coach (sometimes called auxiliary or domestic) battery by the vehicle's charging system as the engine runs. It does this while prioritizing the chassis (sometimes called engine or main) battery, always keeping it at optimum charge.
• It must secondly isolate the chassis battery when the charging system is switched off. This prevents coach equipment from discharging the chassis battery. It will also prevent engine starting from draining the coach systems. Modern units use microprocessors to control both functions.
• It must thirdly insure the batteries cannot equalize, a problem whereby a low battery will siphon power from one with a higher charge, often to a point where neither are usable.

[twinboat]

Originally Posted by krudawg

Had the exact problem on my last trip. I called Magnum Inverter Tech Rep who had me run a couple of checks. He determined that that was NO power on the input side. I was shocked because I hooked it up and like I always do, flip the power CB's to "ON". At least I thought it was on but in reality, the CB's were already "ON" so I had turned it off. I had got into a habit of flipping the CB's because most people turn them off before unplugging their rig. NOW, I actually look at the CB's and find that 98% of them are turned off by the previous tenant before they disconnect their rigs but the other 2% just unplug

You didn't have the exact same problem.

Your inverter/charger has nothing to do with the chassis charging system sending a charge to the house batteries.