2016 Vegas Chassis Battery Replacement - Page 2

tigwelder · 12-23-2016, 06:05 AM

thanks Chucke

bevedfelker · 12-23-2016, 04:18 PM

Well I suppose technically he's right it doesn't charge from the generator (per se). The generator provides AC current to the Automatic Transfer Relay. The shore power connection also provides power to the automatic transfer relay.

AC power is then routed to the Converter. The converter converts the AC to DC and also routes AC power to the AC circuit breakers on the converter panel for all the AC systems. The DC from the converter is routed to the converter's DC power distribution panel for the RV DC systems. It also routes DC power to the converter's charging system that sends DC power to the house batteries and/or chassis battery under certain conditions.

The Axis/Vegas is equipped with a Battery Control Center (BCC) or the infamous BIRD/Trombetta. Regardless of whether there is a BCC or BIRD/Trombetta they function the same. There is a sensing circuit (in BCC or the BIRD) that senses the charge state of the chassis AND/OR house batteries. This sensing circuit monitors both battery banks and when it senses one dropping below 13.1 volts for 2.5 minutes, it sends a dc signal to the isolation relay in the BCC or to the Trombetta to drop the fully charged battery bank out and connect the other bank for charging. It monitors the second bank again for 13.1 volts after 2.5 minutes and reverses the isolation circuit to charge the other bank. As long as there is AC power being provided from either shore power or the generator the converter, BCC, or BIRD/Trombetta will keep BOTH the chassis and house batteries fully charged.

So again -- the generator or shore power provides AC current only. The Converter distributes AC current to the AC systems and converts
AC power to DC power for distribution to the DC systems and for the battery charging system in the converter. The BCC or BIRD/Trombetta senses, isolates, and regulates the charge state of both the chassis battery and house batteries. The USE/STORE switch must be in USE for the house batteries to charge. When going down the road (generator not running and no shore power) the engine driven alternator provides the AC current that is converted to DC to charge the chassis and house batteries. Even when driving down the road, the BCC or BIRD/Trombetta function exactly the same as when on AC power from the generator or shore power.

If the house batteries are not charging when USE/STORE is in USE and power is provided from the generator, shore power, or the alternator something is not functioning correctly. Also if the chassis battery is not charging when on generator, shore power, or the alternator again something is not functioning correctly.

Oneilkeys · 12-23-2016, 04:49 PM

All true Ed, except for the Use/Store switch must be in the Use mode for the coach batteries to charge. It has always been a bit hazy in my mind exactly how the BIRD/Trombetta system is wired in the Axis/Vegas. During this discussion, I went and checked my charging systems again and what I found is the Use/Store switch must be in the Use mode for the house batteries or the coach battery to be charged using shore power or the generator. However, when the engine is running, the alternator will charge both the chassis and house batteries even when the Use/Store switch is in the Store mode. You can easily check this by turning on your engine with the Use/Store switch in Store mode and checking the charge on the house batteries. You will find that the house batteries are being charged even with the Use/Store switch in the Store position - at least mine is. However, if you open the circuit breaker in the battery box, while the chassis battery will still charge when the engine is running, the coach batteries will not, whether the Use/Store switch is in Use or Store mode.
This is because the system is wired from the chassis battery to the Trombetta to the circuit breaker in the battery box to the coach batteries and then from the coach batteries to the circuit breaker to the Use/Store switch and to the coach. The transfer switch feeds back through the Use/Store switch to the circuit breaker and to the coach batteries. So the Use/Store switch separates the transfer switch and coach from the coach batteries but it does not separate the coach batteries from the chassis battery. The circuit breaker in the battery box separates the coach batteries from everything and when it is open the coach batteries will not charge from any of the three sources.

axis earl · 12-23-2016, 06:02 PM

This is why I like this forum. Information from people that have some experience helping those of us that don't. In response to the question I asked before about the chassis battery being charged by the generator and shore power... as I said before, the service writer at Giant RV told me that the chassis battery was a stand alone and totally separate. Ed and others said that is not the case.

I send the question to Thor Customer Service last evening and to my surprise, I received a telephone call from Brandon at Thor this morning! He said that the generator should charge all batteries including the chassis battery, something must be wrong with a relay, etc., and the technicians at the dealership should know what the problem is. I had the coach in last week to get authorization under the warranty, ending soon to fix some minor things: weather stripping around inside of door glass falling out, interior curtains disintegrating and not so minor, what I call fiberglass crazing cracks coming from the right and left grill opening on the engine access hood. Brandon also said that even though Giant RV was only requesting authorization to do body work, Thor was going to replace the entire hood. Awesome. Thanks again to this forum, Ed and others and Brandon at Thor.

bevedfelker · 12-23-2016, 06:02 PM

Richard -- thanks for that correction on house batteries charging off the engine driven alternator. I had assumed the USE/STORE had to be in USE because I thought it was wired through the USE/STORE switch. I'll go back and make a revision to what I have in the manual to be sure it is an accurate description. It seems we get a lot of "traffic" here in the forum about when and under what conditions the chassis and house batteries charge.

I'd bet that that loop you describe from chassis battery, to Trombetta, to battery box CB, to coach batteries could be the source of the small load that tends to drain down the coach batteries when the switch is in STORE. There could be very low impedance as a result of the Trombetta and the engine driven alternator having a path that is potentially connected.

Whenever I'm driving I put the USE/STORE in USE so that the radio display works with the cameras.

Oneilkeys · 12-23-2016, 06:45 PM

Absolutely. Whenever I forget to turn on the Use/Store switch, the Axis reminds me by not having any backup camera. Some of the coach battery drain could be from the loop to the Trombetta and the BIRD. I am not sure where the BIRD is powered from. If it is directly from the coach batteries and not thru the Use/Store switch, that could be a small source of power drain.

Chucke · 12-23-2016, 11:01 PM

Hello Fellas, I want to thank all of you for the information. It is a system I have never had any experience with. Your comments have really explained this system to me. I would be remiss if I did not throw a great big thank you out to bevedfelker, Thank you Col, I have saved your work to my desk top on my lap top. Wow you put a lot of effort into this document. Well I am going to post a new thread and name it Front end alignment. Talk with you Great Americans later!

Carol · 12-24-2016, 05:15 AM

All three batteries in my 2015 Vegas 24.1 died. I didn't like the idea of going through the dash desk to get to the cranking battery so I called and talked to a Thor tech. He said that it can be done by turning the wheels to a hard left and having two guys do the work---one handing battery down from the top and the other under the unit to "catch" it. I took my RV to my regular car mechanic and his fellows did the job without going through the dash---so I guess it really can be done that way.

Oneilkeys · 12-24-2016, 01:12 PM

Quote:

Originally Posted by Carol

All three batteries in my 2015 Vegas 24.1 died. I didn't like the idea of going through the dash desk to get to the cranking battery so I called and talked to a Thor tech. He said that it can be done by turning the wheels to a hard left and having two guys do the work---one handing battery down from the top and the other under the unit to "catch" it. I took my RV to my regular car mechanic and his fellows did the job without going through the dash---so I guess it really can be done that way.

That is interesting. Wonder why Thor doesn't put information like that out to take owners. Thanks for sharing.

Chucke · 12-24-2016, 02:29 PM

Thanks for letting us know. I hope I am good for 3 to 5 years!

petew · 12-24-2016, 03:04 PM

Guess I'll jump on the bandwagon here...
Got my Christmas present from my 2016 Vegas this morning in the form of a dead chassis battery.
My dealer when asked told me that the chassis battery did not charge with the house batteries when plugged in. But after reading what had been said here on the forum and after checking with a meter determined that yes it does and is charging when plugged in .
So why did this thing go dead ?
I have the chassis battery on a separate charger right now and the coach is unplugged , Later in the day I'll see what my voltage reading is.
We are leaving for Disney on Jan 13th and am wondering if I should replace this battery ?
Nothing was turned on that would have killed the battery that I am aware of.
Guess I'll check for draw after (if) the voltage comes back up.
Coach batteries show full charge.

Oneilkeys · 12-24-2016, 03:57 PM

Did the chassis battery go dead while the coach was on shore power? If the coach was left unplugged for a while, there are parasitic loads on the coach battery when the engine is off and the coach is not plugged in. Many people put a knife switch on the chassis battery to cope with that. Others (like me) put a small solar or plug in device to keep the battery fully charged. Starting batteries are not designed to take very many deep discharges before they are toast.

petew · 12-24-2016, 04:39 PM

Battery went dead while the coach was plugged in to shore power and in a climate controlled garage. Battery switch was in the "use" position .
I am in the garage and the rv every day so I can say with pretty good certainty that nothing was left on.
I have had batteries in some of my old cars do this to me in the past , good one day and stone dead the next. Some while connected to a battery charger as was the case here.
This rig sat on a dealer lot for close to a year so there is no telling what kind of abuse the chassis battery suffered during that time.

gmc · 12-24-2016, 05:29 PM

Quote:

Originally Posted by petew

Battery went dead while the coach was plugged in to shore power and in a climate controlled garage. Battery switch was in the "use" position .
I am in the garage and the rv every day so I can say with pretty good certainty that nothing was left on.
I have had batteries in some of my old cars do this to me in the past , good one day and stone dead the next. Some while connected to a battery charger as was the case here.
This rig sat on a dealer lot for close to a year so there is no telling what kind of abuse the chassis battery suffered during that time.

With RV plugged in - leaving something 'on' shouldn't be an issue... You said you confirmed the battery was being charged - may be just a dead battery... as you said may have been 'abused' before you got it.
Be curious to see what it does on the external charger... If the charger has a 'rejuvenation' setting of some sort - may be worth a try.

Oneilkeys · 12-24-2016, 06:41 PM

I can't imagine why it would be dead when ithe RV was charging with shore power and you checked to see if the chassis battery was charging thru the Trombetta. It must be very dead. What voltage does the start battery read after you unplug and leave it to stabilize for a while? I would say start the engine with the emergency start switch and see if the alternator charges the start battery.... But you have to be careful that the start battery is not completely dead. I started a car once with jumper cables and did not let the dead battery recharge sufficiently before I started the vehicle. The battery did not have enough juice in and it blew the engine computer. Expensive mistake.

petew · 12-24-2016, 07:17 PM

Well it charged @ 8 amps for a couple of hours ,jumped right up to 12.4 volts and started right up.
Plugged the shore power back in and the voltage stayed at 12.4 volts . Started it and it jumped up to 14.0 volts so apparently at some time in the last month it has stopped charging off of shore power.
Checked for voltage draw while turned off ( test light between disconnected + cable and terminal ) and the test light shone brightly ! So apparently there is a draw.
Now I know there is always a draw from the engine computer but that light was glowing pretty good.
Took Oneilkeys advise and went out and purchased a knife switch for now.
So if this were a warranty issue who would own it , Ford or Thor ??

Oneilkeys · 12-24-2016, 09:25 PM

Thor will say Ford and Ford will say Thor - guaranteed. It could be that, for some reason, the Trombetta malfunctioned and closed so that Shore Power no longer charged the chassis battery. Then over time the chassis battery drained down. Turning off shore power and turning it back on could have reopened the Trombetta charging the chassis battery. I would leave it plugged into shore power and check and see every few days or so to see if the Trombetta is still open and the chassis battery is still charging.

Oneilkeys · 12-24-2016, 09:43 PM

Sorry, I reread your post and apparently your chassis battery is not charging under shore power at all. Is that correct? If it is not charging, something is wrong. The way it is supposed to work, when shore power or the generator is turned on, the BIRD (if you have one) is supposed to sense the voltage on the house batteries. When that voltage hits 13.1v, the BIRD opens the Trombetta connecting the two battery banks charging the chassis battery. The first question is does the sysytem work the other way. Does the alternator charge the house batteries as well as the chassis battery? If it does not, you probably have a bad Trombetta. If it does, the system may be miswired or the BiRD is bad.

petew · 12-24-2016, 09:55 PM

Yes, I do have a bird (drivers side of the engine compartment ) And I will check tomorrow to see if the alternator is charging the house batteries.
The chassis battery is not charging when on shore power at all, although a month ago it did

Where is the Trombetta located ?

Also discovered that the house batteries when not connected to the charger and with nothing turned on show 12.48 volts which seems to me to be too low.
I know the house batteries provided by Thor are low quality so even if my chassis battery bounces back ( which it seem to be doing) The house batteries may be toast.

petew · 12-24-2016, 10:16 PM

Quote:

Originally Posted by Oneilkeys

Sorry, I reread your post and apparently your chassis battery is not charging under shore power at all. Is that correct? If it is not charging, something is wrong. The way it is supposed to work, when shore power or the generator is turned on, the BIRD (if you have one) is supposed to sense the voltage on the house batteries. When that voltage hits 13.1v, the BIRD opens the Trombetta connecting the two battery banks charging the chassis battery. The first question is does the sysytem work the other way. Does the alternator charge the house batteries as well as the chassis battery? If it does not, you probably have a bad Trombetta. If it does, the system may be miswired or the BiRD is bad.

Just reread your post and wondered if my house batteries are only getting to 12.48 volts could this be causing the Trombetta to keep the chassis battery out of the loop ?
House batteries do indicate a 13 + volt rate of charge but disconnect the shore power and they drop to the 12.48 immediately.

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