Charging House Batteries from Alternator

[ABrask]

Had to take my 33.2 on a short run this morning and noticed that it would not charge the house batteries from the alternator. I started the generator, and the charging light immediately went on. I also had a low voltage message on the leveling panel (powered from the chassis battery as I recall), and I seem to remember that the alternator won't charge the house batteries if the chassis batteries are low, but I may have been dreaming. Anyone have any ideas or able to give me a refresher course on this subject? Thanks!

[twinboat]

Not dreaming.

The priority of the engine charging system is the chassis battery.

If it was low, the combining system will not activate to charge the house bank until the chassis is up to 13.5 volts.

Even then, if house bank is also low and pulls enough power from the chassis battery, to less then 13.5 for a minute or so, the system disconnects the house bank for 10 minutes.

It will do this multiple times, until the chassis battery remains at 13.5 volts or more.
Remember, the chassis battery is always priority.

The system is a BIRD or IRD.

Bi-directional Isolation Relay with Delay ( It works with the alternator or converter to keep both battery banks charged )

Isolation Relay with Delay. ( It only works with the alternator, not the other way )

[NettieRegina]

ABrask :I started the generator, and the charging light immediately went on.

If you're referring to the Onan generator and the "CHG" light on the Magnum Energy remote control, I don't think that light has any association with the engine alternator it only shows there is 120vac power being supplied to the charge-section of the inverter.

My Ultra-Level panel has a "Low Voltage/Run Engine" indication that often illuminates while the alternator is stabilizing at around 14 volts, as the alternator output voltage fluctuates for a few seconds immediately after starting the engine. Once your alternator dash-gauge is stable above 13.1 volts for 2.5 minutes, the BIRD should close the battery-isolator-relay and allow the alternator to also charge the house batteries. Only if your dash-gauge falls below 12.0 volts for one minute will the BIRD open the isolator-relay, and with a 160-amp alternator I think that should be a rare occurrence.

From your description I'm not sure how you determined that the house batteries are not being charged by the alternator.

The attachment might be helpful for your troubleshooting.
Good luck
Gary

[SS573]

Originally Posted by ABrask

Had to take my 33.2 on a short run this morning and noticed that it would not charge the house batteries from the alternator. I started the generator, and the charging light immediately went on. I also had a low voltage message on the leveling panel (powered from the chassis battery as I recall), and I seem to remember that the alternator won't charge the house batteries if the chassis batteries are low, but I may have been dreaming. Anyone have any ideas or able to give me a refresher course on this subject? Thanks!

The same thing happened to me on our Alaska trip in 2014. The problem is the parallel contactor. On my coach it is a Trombetta P/N 114-1211-010. ( It was supposed to have been replaced under warranty but apparently was not). Their web site shows that model has copper contacts while the -020 model has silver coated copper and is supposed to reduce the problem.....I ordered the -020 from Amazon for $75 and replaced it myself. Problem solved. BTW...I also installed the Magnum inverter Battery Monitor module and shunt. That told me absolutely if my house batteries are charging.

[ABrask]

Originally Posted by SS573

The same thing happened to me on our Alaska trip in 2014. The problem is the parallel contactor. On my coach it is a Trombetta P/N 114-1211-010. ( It was supposed to have been replaced under warranty but apparently was not). Their web site shows that model has copper contacts while the -020 model has silver coated copper and is supposed to reduce the problem.....I ordered the -020 from Amazon for $75 and replaced it myself. Problem solved. BTW...I also installed the Magnum inverter Battery Monitor module and shunt. That told me absolutely if my house batteries are charging.

Thanks SS573.... And that Trombetta part was on your Palazzo 33.2, correct? And this is in the battery bay?

[SS573]

The relay on my coach is mounted behind the inverter. The control module is mounted rearward of that...near the cooling fan for the bay.

Yes..that's the part number of the relay but I replaced mine with the part number ending in -020 which is the silver coated contacts.

I'm also disassembling the old relay to see if it's recoverable enough to use as a backup.

Hope that helps!! 😃


2015 Thor Palazzo 33.2

'97 Ford Ranger Toad until I can get something new.

[BillSkeen]

Wow, I always wondered why my chassis batteries were low when I turn the ignition on, even when on shore power charging, while motorhome is stored. After reading through all these posts on the BIRD, it sounds like mine is not charging them.

[SS573]

That happened to me also. The solenoid allows the inverter/charger to charge the chassis batteries while on shore power or generator as well as charging the house batteries while driving.


2015 Thor Palazzo 33.2

'97 Ford Ranger Toad until I can get something new.

[NettieRegina]

Originally Posted by BillSkeen

Wow, I always wondered why my chassis batteries were low when I turn the ignition on, even when on shore power charging, while motorhome is stored. After reading through all these posts on the BIRD, it sounds like mine is not charging them.

It's easy to test.

1. Shore power on
2. Check that the battery isolator relay (Trombetta) is energized by measuring voltage across its small terminals: should register approx. 12v
3. Check the voltage drop across the large terminals: any more than "a few millivolts" - replace the relay.
   
   http://www.irv2.com/forums/f281/repl...or-290818.html

Gary

[ABrask]

Originally Posted by SS573

The relay on my coach is mounted behind the inverter. The control module is mounted rearward of that...near the cooling fan for the bay.

Yes..that's the part number of the relay but I replaced mine with the part number ending in -020 which is the silver coated contacts.

I'm also disassembling the old relay to see if it's recoverable enough to use as a backup.

Hope that helps!! 😃


2015 Thor Palazzo 33.2

'97 Ford Ranger Toad until I can get something new.

Thanks for this info. Any chance you could photograph where this is located and give some idea what it took to replace it? (I'm not near my coach right now.) Thanks!

[SS573]

No problem!! I'll do it when I get home today. 👍🏻👍🏻


2015 Thor Palazzo 33.2

'97 Ford Ranger Toad until I can get something new.

[ABrask]

Originally Posted by SS573

No problem!! I'll do it when I get home today. 👍🏻👍🏻


2015 Thor Palazzo 33.2

'97 Ford Ranger Toad until I can get something new.

You are a gentleman and a scholar. Thanks!

[SS573]

HA!! Thanks. 😃

Here are a few pictures that I hope will help.

The first shows the contactor behind the inverter. It's close so remove all A/C and DC power before removing the relay.



This is a closeup of the relay. Note the heavy cable. One side goes to the house battery while the other is the chassis battery. Other cables are for other "stuff".



This last one shows the relay control. The terminal marked "relay" is...you guessed it...the relay coil. 😁



Again. My recommendation is to Remove ALL power before changing out the relay.

PM me if you have questions.


2015 Thor Palazzo 33.2

'97 Ford Ranger Toad until I can get something new.

[ABrask]

Thanks.... I checked the part number on mine while we were out this weekend, and I indeed have the 01. I've ordered the 02 from Amazon and plan to swap it out as soon as it arrives. Hope it solves the problem for me as it did for you, as I also confirmed the house batteries are not charging from the alternator while on this trip. I'll let you know how it goes.