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-   -   Charging problems? (https://www.irv2.com/forums/f115/charging-problems-323115.html)

clyon51 01-10-2017 07:43 PM

Charging problems?
 
New to me 07 Dynasty Palace III. Coach batteries are always being charged property on the various charging rates. Chassis batts (via volt meter) are always well under 13v, but always above 12.5.... but never even close to house batts.

So I know they are being charged, but I suspect only by the solar panels which Alladin says is putting out 24v and charging a few amps during the day.

After reading in here, it sounds like the big boy is not working? Or is this normal for this coach? BTW, I have yet to fix the BB.

K7JV 01-10-2017 08:28 PM

John, I'm sure you know the Big Boy is in the rear run box, in the upper right corner (looking in the back hatch) of the engine compartment. The Big Boy is the single largest device in there. Put your hand on it, and it should be warm to quite warm to almost hot. If so, that means it is "picked", and the two batteries should be connected together thru it. Take your voltmeter and read the voltage from one of the large bottom lugs to the other large bottom lug. You should read very nearly zero volts.

If the solenoid is picked and there is much more than 0.1 to 0.2 volts across those lugs, the contacts are sufficiently pitted to need either significant maintenance or replacement. If you are handy with tools, you can do it. Or you can just replace the Big Boy. Just be sure to open both physical disconnects in the battery compartment while working in there, and remember that a couple of those large lugs in the rear run box are ALWAYS hot! So be careful with your tools. You won't get shocked by anything in there, but you can scatter some bits of molten metal around, pretty easily if you short one of those hot lugs.

If the solenoid is cold, try pressing the top of two yellow buttons on the circuit board on the extreme right side of the run box. It is labeled ISO RLY SW on our coach. If the Big Boy isn't energized, this will energize it. If it is already energized, I don't believe that anything will happen when you press this yellow button. If the Big Boy is not sitting energized when on shore power, further testing is going to be needed and further information is going to need to be given to determine the reason.

Good luck. I'd help you in person, but unfortunately we're about 180 miles southwest of you.

CampDaven 01-10-2017 08:48 PM

If you're plugged in and the coach/chassis charge rates are not the same, hit the boost switch a bunch of times. If it evens out, you need a Big Boy. If it doesn't even out, you still need a Big Boy.
I have been stabbing my boost switch for over two years whenever we park or get underway.
Try your finger. Mine still works!

clyon51 01-10-2017 09:05 PM

K7 JV, thanks for the input. There is box in the back with intellitech (sp) on it that I haven't opened yet. Speaking of that, I just found out the coach is doing shedding... The washing machine takes presidency over the cook top 😁 anyway, I'll check it out tomorrow. I've been off IRV for over a year and haven't updated all my info. I'm presently in Yuma.

clyon51 01-10-2017 09:13 PM

Is there a separate solenoid for the boost or does the BB handle handle boost and bird?

K7JV 01-10-2017 09:36 PM

Big Boy does both. I had to rebuild ours when our '06 Dynasty was just six months old. I think they mistakenly put a used one in at manufacture. It's worked almost ten years since, and is still going strong. Knock on wood. And we're in Westwind in Yuma.

As for the "load shedding", take a look at your breaker panel for the high current loads. (One panel is for the high current loads and the other is for the loads that are on the inverter) You will see a 15 or 20 amp breaker serving two large loads such as one of the A/C units and the Washer/Dryer. They may be on the same breaker or on two halves of a split breaker. So when the demand on the preferred load goes high, it cuts out the other high current load out to keep from causing the breaker to trip. Lets them put more loads on fewer breakers and to run less or smaller conductors. Unfortunately it does not do anything for tripping the shore power pedestal breaker.

clyon51 01-11-2017 04:54 PM

Quote:

Originally Posted by K7JV (Post 3411707)
John, I'm sure you know the Big Boy is in the rear run box, in the upper right corner (looking in the back hatch) of the engine compartment. The Big Boy is the single largest device in there. Put your hand on it, and it should be warm to quite warm to almost hot. If so, that means it is "picked", and the two batteries should be connected together thru it. Take your voltmeter and read the voltage from one of the large bottom lugs to the other large bottom lug. You should read very nearly zero volts.

If the solenoid is picked and there is much more than 0.1 to 0.2 volts across those lugs, the contacts are sufficiently pitted to need either significant maintenance or replacement. If you are handy with tools, you can do it. Or you can just replace the Big Boy. Just be sure to open both physical disconnects in the battery compartment while working in there, and remember that a couple of those large lugs in the rear run box are ALWAYS hot! So be careful with your tools. You won't get shocked by anything in there, but you can scatter some bits of molten metal around, pretty easily if you short one of those hot lugs.

If the solenoid is cold, try pressing the top of two yellow buttons on the circuit board on the extreme right side of the run box. It is labeled ISO RLY SW on our coach. If the Big Boy isn't energized, this will energize it. If it is already energized, I don't believe that anything will happen when you press this yellow button. If the Big Boy is not sitting energized when on shore power, further testing is going to be needed and further information is going to need to be given to determine the reason.

Good luck. I'd help you in person, but unfortunately we're about 180 miles southwest of you.

OK found the BB and it was hot. Voltage across the lugs was 0.73. The cables running to the batts was showing 14.0v to the 8 house batts and 13.26 to the chassis... Which makes sense.

No yellow buttons could be found. I did see two switches, one marked 'Start' and one marked Front on top and Rear on the bottom. Both next to each other. I haven't a clue what I would start in the front and have another in the back too. Maybe I have 2 generators 😁. Come down and visit Jim, I'll pick your brain apart 😁

Randyman1 01-11-2017 08:24 PM

Those are start switches so you could start the coach from back there, like in the case of a mechanic working on it and be able to shut it off as well.

K7JV 01-11-2017 10:33 PM

1 Attachment(s)
Sorry about my vague description earlier. I've attached a poor quality photo of the right half of the rear run box. There is a circuit board just to the right of center in the photo. That is the board that controls both the Big Boy and the "Salesman Switch" relays.

Along the left edge of that circuit board are two yellow devices. Those are actually push-button switches. The upper of the two is the one that can energize the Big Boy, if it isn't already energized. The lower one toggles the two relays that constitute the "Salesman switch" relay.

Since the Big Boy is quite warm, it is definitely energized to tie the two batteries together. If that is the case, in my opinion 0.73 volts is too much. And some of the heat of that device is from the I-squared-R losses across the contacts as well as from the energized coil.

You are right that the chassis battery is getting charged, but not as effectively as it should be.

I hope that makes some sense.

And yes, the two switches are for starting the main engine from the rear of the coach. You have to have the dash "ignition" key in the on (Run) position for the start function to work with the switch in the "Rear" position. In the "Rear" position, you can start and stop the engine with the "Start/Stop" switch. That's handy when you are working in the rear of the coach and don't or can't run back and forth to the cab to operate the engine. Remember, if you don't switch it back to "Front" when you're done, you'll wonder why you can't later start the engine until you remember about those switches. Been there, done that.

YC1 01-15-2017 08:10 AM

Jim nailed it. That voltage drop is too much. It should be 0. That huge solenoid should be providing a dead short inside connecting the large posts.

They can be overhauled if you are confident and really careful. There are hundreds of pages on the subject. But the works Big Boy in the little google search are above and you will have some fun reading.

K7JV 01-15-2017 08:29 AM

4 Attachment(s)
Here are four pictures of our Big Boy "innards" taken in June of 2006. The coach was only six months old. I'm absolutely sure they inadvertently put a used and damaged Big Boy in our rig, new! Anyway, I used nothing more than a brush wheel on a Dremel to clean the contest and associated pieces, cleaned out the cap, reassembled and reinstalled it, and it is working great to this day. My spreadsheet log shows that we have "lived" in our coach over 40% of the time since it was new.

The photo with the nut driver in it shows the condition of the contacts and the disk immediately prior to re-assembly. So you can see that they don't have to be spotless perfect. They just need to be good mating surfaces that are as free from dirt, contamination or oxidation and pitting as you can reasonably get them.

RobRoy 01-15-2017 09:18 AM

Following this thread, it is amazing the sage information you guys bring to the table.

I want to wrap my head around a couple of things and need some help to understand.

I agree that .73 voltage is excessive and that the Big Boy needs to be addressed either with repairing or replacing it.

I'm having difficulty understanding how .73 Voltage Drop would affect the charging rate of the chassis batteries and if someone could please explain?

As far as diagnosis goes as to the Big Boy being the culprit? couldn't you just use a heavy duty jumper cable and jump across the BB terminals and see if the charge rate changes? Or jumper a battery cable with eyelets across the terminals of the big boy?


I think that what CampDaven has posted in post # 3 about pushing the “ boost” button a few time to activate the Big Boy a few times could be very telling in a diagnosis and a simple test, that is if I have the correct understanding of how this system works.

I would also like to know the charging rate on those chassis batteries with the coach running and charging from the engine alternator, because it could be very telling as to the condition of those chassis batteries. If I see a slightly lower than normal charging rate ( voltage ) and constantly high amperage rate to those from the engine alternator after running for 15 min ……. I'm going to be testing those chassis batteries a bit further.

Just trying to get an education and Thanks again

Windecker 01-15-2017 10:23 AM

The voltage that is "created" between these two posts is just the potential being measured not as .73 volts loss but .73 volts measured loss rate due to a poor connection or resistance.

Think of it more like a garden hose is turned on at the house supply, this represents your alternator supply voltage in.

Next the nozzle at the end of the hose is off, hose fully pressurized, this represents the alternator supply into the BB relay engine running.

Next pull the garden hose on all the way and water sprays full blast. Pressure in the hose is nearly the same on the hose side as the outlet of the hose nozzle. This is similar to the alternator output going through the BB relay and into your batteries to charge them.

Next pull the garden hose on only partially, the water comes out at a slower rate. Pressure in the hose is high, flow rate out the nozzle is low. There is a noticeable/measurable difference in the water pressure between the hose and outlet of the nozzle. This represents your BB relay restricting the amperage flow through it and is a measurable difference. The less the difference, the less the resistance or the more open the nozzle is.

As far as testing with jumper cables, yes, you can do that but be careful not to short anything out in there and take the cable off before you crank the engine.

Hope that helps!
Windecker

Quote:

Originally Posted by RobRoy (Post 3417285)
Following this thread, it is amazing the sage information you guys bring to the table.

I want to wrap my head around a couple of things and need some help to understand.

I agree that .73 voltage is excessive and that the Big Boy needs to be addressed either with repairing or replacing it.

I'm having difficulty understanding how .73 Voltage Drop would affect the charging rate of the chassis batteries and if someone could please explain?

As far as diagnosis goes as to the Big Boy being the culprit? couldn't you just use a heavy duty jumper cable and jump across the BB terminals and see if the charge rate changes? Or jumper a battery cable with eyelets across the terminals of the big boy?


I think that what CampDaven has posted in post # 3 about pushing the “ boost” button a few time to activate the Big Boy a few times could be very telling in a diagnosis and a simple test, that is if I have the correct understanding of how this system works.

I would also like to know the charging rate on those chassis batteries with the coach running and charging from the engine alternator, because it could be very telling as to the condition of those chassis batteries. If I see a slightly lower than normal charging rate ( voltage ) and constantly high amperage rate to those from the engine alternator after running for 15 min ……. I'm going to be testing those chassis batteries a bit further.

Just trying to get an education and Thanks again


clyon51 01-15-2017 11:41 AM

When I tested mine (0.73v across the poles) the coach side was 14v. The chassis side output was only 13.26v ... So there is the difference.. 0.73v. perhaps a coincidence. Anyway, when I get time, I'll take it apart and clean it up. It is 10 yrs old.


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