Does Generator Charge Bus Batteries??

[0533]

I am dry camping and have the 12/24 volt bus battery switches off. Prevost said to do this and it will not effect the Computer when turned off. I have no bus battery charger ( have ordered one that Mango recommended, arriving state side) and do not want to run the bus batteries down.

I start the genset twice a day, in the morning for a few hours and in the evening for a few hours, maybe a total of 4 hours. I leave the genset on auto start as well.

Question: When I am running the genset does it or would it charge the bus batteries at the same time if I had them turned on, or does it charge them anyway. I am thinking it does not, as it would create a problem when the bus engine is on running down the highway with the genset creating an overload unless it is smart enough to cut the circuit off during these times?

[jack14r]

My 2001 Marathon that JDUB now owns did not charge the chasis batteries with the generator,it had a switch which would connect the house and chasis batteries for starting the Detroit Diesel if the chasis batteries were not charged.That switch had to be held down to connect all batteries and it was current limited.

[phorner]

My generator does not charge the chassis batteries, hence the need for the aux battery charger, which Truk and I installed and it has worked like a charm.

Once you have yours installed, that will be your ticket to charging the chassis batteries while running the generator.

Just something for you to think about, the charge rate setting on your inverter/charger(s) will impact the time required for your generator to run to fully charge your batteries. Of course, the beginning state of charge will also matter.

[nrhareiner]

Good afternoon,

Unless or until you install the battery charger, your generator will not charge your chassis batteries. Also, I am not sure, but I do not think that two hours twice a day generator use will ever get your coach batteries up to full charge state.

Once you get the charger installed, the chassis batteries will receive charge whenever you are plugged in or generator is running. I have that system installed, and it works great.

[truk4u]

Generator does not charge the chassis batteries. While at Osh drying camping for 5 days, it took mine 3 hours of generator time to bring the house batteries back up to float from a discharge of 12.2.

Country Coach Owners... I was pleasantly surprised when I discovered my auto-start was hard set to start at 12.1 volts. Someone must have done some work on the board, as the manual says it comes on at 10.8 which is ridiculous and would destroy the batteries. I only used it a few times since I was trying to be a good neighbor and not let the gen start at night while everyone was sleeping with the windows open.

Mango on the other hand, let the stink mobile fog every living thing within 200 yds of ground zero. Never dry camp with him, his gen needs serious servicing and smokes like a chimney burning empty jerk chicken boxes.:o

[jello_jeep]

Poor Bruce needs to know about the jump switch, in case he has to make a quick run from the Mounties :) , runnin all that stolen canuk fuel! :D

[Darl-Wilson]

Tom, why don't you tell EVERYONE how you really feel about the state of Mango's gen? Great description!:D

Darl

[Jon Wehrenberg]

I am still concerned about why some bus chassis batteries drop voltage so fast, with or without the master switches "off".

My bus last moved in mid June. Once parked I haven't run it. Last week the batteries were at 24.8 volts (12.4) so I kicked on the charger to top them off. My master switches were on the entire time. My 87 was the same way in that I never turned the chassis master switches off and I would still be able to start the bus after 2 or three months.

Truk, does CC have some phantom loads on the chassis batteries?

[merle&louise]

I'll start a new thread about the Mango's smoking generator.

[0533]

Thanks guys, I thought as much and when I get my charger installed all will be well.

I do not understand like Jon what is running these batteries down so fast when the bus is parked?

Also I mentioned that I run the genset twice a day, from 8-10, and from 6-9, or about 5 hours, I was wrong when I said 2 hours twice day. I am not running much power in the coach and no air, the heat is on in the AM when the genset is on, same at night when cooking etc. I do not get the batteries to the float position, and the auto gen mode does not come on at night.

How important is it to get to the float position each time??

[Jon Wehrenberg]

Bruce,

It sounds like you have the apples mixed up with the oranges.

I will be doing a seminar on this in Spearfish, but the short version is your bus batteries are not getting charged while your engine is off regardless of how long you run a generator or if you are connected to shore power unless you have a battery charger dedicated to the chassis batteries, and it is turned on.

The house batteries are charged automatically when the engine is running, when connected to shore power and when the generator is running because your inverters are on all the time and when the engine is running the alternator is charging them.

[truk4u]

Jon - My CC and the previous Marathon is like yours, it can set a long time with no problem and still have 24 + volts and I never turn off any of the switches. I suspect some of these with short chassis battery life when the switches are off is caused by a bad battery(s). One weak cell can drag down the group in short order. Even new batteries as we know can be bad.

Bruce - Letting the charge get to float assures you have put a full charge back in the batteries and the next cycle of use will last as long as possible. If you cut it off during absorbtion, your not getting a full charge. I experimented a little with this and it makes a difference. Also, remember 12.2 volts is 50% discharged.

[0533]

Jon - My CC and the previous Marathon is like yours, it can set a long time with no problem and still have 24 + volts and I never turn off any of the switches. I suspect some of these with short chassis battery life when the switches are off is caused by a bad battery(s). One weak cell can drag down the group in short order. Even new batteries as we know can be bad.

Bruce - Letting the charge get to float assures you have put a full charge back in the batteries and the next cycle of use will last as long as possible. If you cut it off during absorbtion, your not getting a full charge. I experimented a little with this and it makes a difference. Also, remember 12.2 volts is 50% discharged.
Thanks Tom,

I will wait until it floats before turning off the genset.

I had new Chassis batteries installed in Coburg last December, who knows one may already have bad cells, how do I check for this with sealed batteries??

[Jon Wehrenberg]

This is a comment to all and relates to Bruce's concerns.

Our batteries are our lifeblood and because of that we need to treat them with respect. At the very least all owners should go to various sites such as these:

http://www.lifelinebatteries.com/rvbatteries.php

http://www.windsun.com/Batteries/Battery_FAQ.htm#Using%20a%20deep%20cycle%20battery %20as%20a%20starting%20battery

The important thing is to understand batteries, how to charge them, and what impacts their life.

The next step obviously is to get to know your coach. How is your inverter set up for charging? What is the charging voltage of your alternator? Do your batteries hold a charge or are they losing a charge? If they are losing a charge why are they losing a charge? Putting on a charger to compensate for batteries going dead is akin to taking an aspirin for a brain tumor. It masks the underlying problem.

To address Bruce's question specifically, there is a simple way to determin if you have a bad battery. Separate the batteries electrically (take the cables off them) and using a battery tester check them to see if they are just in need of a charge or if they have gone bad. In the absense of a tester, there is another way, but it will be inconvenient if you are living in the coach. Separate the batteries electrically. Measure and record the battery voltage for each battery. Do not reconnect the batteries or use power from them, but let them sit overnight. Remeasure the voltage after a 12 or 24 hour period. If you have not pulled any power from them they should have retained the voltage measured the day before. A bad battery will show a much lower voltage.

In the case of chassis batteries this should be no problem, but if your house batteries need to be checked you really can't use the second method if you are using the coach.

I will maintain my original position on this. If the chassis batteries are losing a charge within days or even a couple of weeks there is something pulling them down. As Tom points out it could be a bad battery or there is a load on them that needs to be determined. There should be no loads with the switches turned off except possibly some DDEC circuits. Those circuits should have minimal current draw, if any.

[truk4u]

Good advise from Jon, but be sure you test the batteries with a load tester, not just a meter.

[Ray Davis]

I may be on the wrong tack here, but the Marathon coaches have a control panel to set the charging rate for the house batteries. I know this affects the incoming shore power, in case you are connected into a 20 or 30A service.

What I don't know for sure, will that affect the charging rate, if the genset is running. IF so, then perhaps your charging rate is set too low, and you're not coming up to charge in the time you're running the genset?

Ray

[Jon Wehrenberg]

This is a tough place to get into a deep discussion, but Ray's comments are also on the right track. If the generator is set for auto-start the house batteries should get a full charge before it shuts off. If the coach is used for a lot of dry camping that means the charge rate on the inverters needs to be set to its maximum.

But if the coach is used for a mix of dry camping and full hookups then when connected to shore power it is probably the lowest charge rate needs to be selected otherwise power management becomes an issue. When using low amperage hookups like 20 or 30 amps a high charge rate will likely result in tripped shore power breakers if any other devices are used such as AC units.

Note however this has nothing to do with a chassis battery issue. Shore power, generator power, or no power should have zero affect on the charge of the bus batteries unless the coach has a chassis battery charger and it is turned on when using shore or generator power.

[0533]

My friend next door to me (the Michelin factory manager) has a portable bank of solar panels that he can position for the best sun location, each one produces 80 watts, X 3.

has anyone considered this method for either house or chassis battery charging. I mean on a larger scale, not as a trickle charge, but with an array of panels with lets say 1,000 watts, would this have any real benefit when dry camping and how would one connect it to the coach grid?? Like to come up with a way to beat the genset requirement.

[Jon Wehrenberg]

Let's say your refrigerator uses 7 amps. That is 840 watts.

My guess is that the array of solar panels just to keep pace with the most basic loads would need to provide 1500 watts because on our coaches we have a lot of "key-off" loads ranging from tank level sensors, to the alarm system, to clocks, outside thermometers, to the water pump etc.

Of course you could get away with less wattage if you set your charge time to the night when loads are less.

[0533]

Let's say your refrigerator uses 7 amps. That is 840 watts.

My guess is that the array of solar panels just to keep pace with the most basic loads would need to provide 1500 watts because on our coaches we have a lot of "key-off" loads ranging from tank level sensors, to the alarm system, to clocks, outside thermometers, to the water pump etc.

Of course you could get away with less wattage if you set your charge time to the night when loads are less.
There is a lot of load for sure, but with the cost of fuel and the hassles it is a subject worth investigating. I will do some research and report back. I have to believe there are solar options sized and large enough to meet the the demands of our buses.

[ronwalker]

Bruce, I've been living very comfortably with my 1100 watts of solar and haven't needed to run my generator (other than to exercise it) since January. However, 14 solar panels (8x100 + 6x50) are hard to justify if you're not fulltiming. Also, dedicating that much roof space to solar may require the use of :eek: basement air. My 24 volt 3-stage solar charge controller usually has my 8 8D glassmats in float mode by 10am and has my starting batteries up as well. I don't have my big 24 cu ft Jenn Air fridge running on 24v. yet, but spreadsheet calculations show I should not be forced to run the generator below 90 F. Summertime highs are usually around 80 F here in Flagstaff. With no sun, my generator charges all batteries through the inverter/charger.

In full sun, I've seen 40 amps @ 24v coming down. That won't handle your 220v cooktop or A/C and you must minimize your phantom loads, but you can nuke lunch and supper and run the computer or TV all evening.

My $.02 worth.

[Ray Davis]

Ron,

That is incredible! Good to hear from you again. Maybe a seminar on solar at an upcoming POG rally? That would be great info.

Ray

[0533]

Bruce, I've been living very comfortably with my 1100 watts of solar and haven't needed to run my generator (other than to exercise it) since January. However, 14 solar panels (8x100 + 6x50) are hard to justify if you're not fulltiming. Also, dedicating that much roof space to solar may require the use of :eek: basement air. My 24 volt 3-stage solar charge controller usually has my 8 8D glassmats in float mode by 10am and has my starting batteries up as well. I don't have my big 24 cu ft Jenn Air fridge running on 24v. yet, but spreadsheet calculations show I should not be forced to run the generator below 90 F. Summertime highs are usually around 80 F here in Flagstaff. With no sun, my generator charges all batteries through the inverter/charger.

In full sun, I've seen 40 amps @ 24v coming down. That won't handle your 220v cooktop or A/C and you must minimize your phantom loads, but you can nuke lunch and supper and run the computer or TV all evening.

My $.02 worth.
Thanks Ron for the excellent comments.

We have some unusual features to our bus that we feel might lend its self well to to a large solar conversion. first we have an 8'X12' observatory on the roof now, with a raised metal deck, stairway inside etc., all of our air is in the bays and we have both a 2 burner electric cooktop and a 2 burner gas cooktop. We also have a new 3 door refrigerator that uses about a KW per day of energy so says the literature.

Anyway we would love to give this a go when we return to Florida, it would make for a great project and it would make dry camping a better experience, we really like those silent nights, and quiet days. We would love to have 1500 watts if possible and be able to charge both the house and the chassis batteries.

Could you share with us the name and source of your solar panels and controller. This would help a lot.

You mentioned that you have 8 house batteries, I think we have 6, but I will check, did you add 2 or were they already in place. How did you connect to the inverters and can you monitor and control the solar panels, levels of output and are you able to move the panels for maximum exposure to the sun?

[ronwalker]

Ray, I could talk a bit about solar at a future western rally, but the value to most POG members won't justify the cost. Reducing generator run time a little will never save enough to pay for the panels. You've gotta be obsessed with quiet living to warrant spending the money and you really need a coach that isn't all electric. I'm now working to silence the jet roar of my AquaHot by tying in my solar water heating panels, but that's another story.

Bruce, If you can stay under the max height limit, a thin raiseable (and tiltable) 8'x12' deck roof of solar panels would be worth some engineering effort. Yes, my panels tilt to double the output in the winter months.

My solar panels are the BP 44 cell AM100's, http://www.amsolar.com/am100.html. They DO outperform other panels when used with this controller at 24 volts: http://www.blueskyenergyinc.com/sb3048.htm. I use a Xantrex echo~charge, http://www.xantrex.com/web/id/103/p/1/pt/8/product.asp, to keep my starting batteries charged. All are available from John Palmer of (shameless commercial plug) Palmer Energy Systems (http://jolynenterprises.com/) who will install everything for you or let you stay at his place in Lake City, FL to install all of it yourself and teach you how to dry camp at the same time.

Remember, my coach was an empty stainless steel and fiberglass tent with empty bays shortly before I wired up a 24 volt house battery bank using 8 8D Lifelines. I tied my single 4000 watt inverter directly to that battery bank. I use my charge controller remote panel and my old Link 2000 "e" meter (http://www.xantrex.com/web/id/99/p/1/pt/7/product.asp) to monitor the system. The solar charge controller automatically controls the solar panels and their levels of output (a 3-stage charge).

I was especially pleased that this solar system was able to provide the power to keep my DD Series 60 running smoothly to Tacoma, WA when I had a complete alternator failure in Canada. Solar powered bus, eh?

'Sorry 'bout the long post, but I hope this helps.

[0533]

Thank you very much Ron.

I especially like the notion that you could back up your Series 60 Alt with solar in a pinch, really cool stuff.

I would also want to find a way to have solar hot water as well.

Its interesting that your friend John Palmer lives in Lake City Fl. That is not too far from Jupiter. I will contact him and make arrangements for a meeting, great info and it would be really fun to sit on the beach somewhere by ourselves with complete independence from power sources.

Any other gadgets or ideas that might make the silent experience more enjoyable?

[phorner]

There was a guy at the FMCA rally with a small wind turbine, like the ones you see on some sail boats, that was attached to what looked like a small, triangular radio tower.

At the base of the tower, which appeared sectional, he had a plug in connection. Looked like the whole thing could be un-plugged, disassembled and stored.

We had plenty of wind during the rally, and I never heard his generator run, although I wasn't paying close attention to it.

The whole thing attached to a bracket rigged to his receiver hitch in place of his tow bar.

[ronwalker]

Wind power is handy in that when the sun doesn't shine, it's usually windy.

Peter Byrne of http://www.setantasolar.com/index.php can tell you all you'll ever want to know about solar water heating. He sells the systems and lives the lifestyle. He's waiting for data on my motorhome application.

Using that beautiful little trout stream that runs beside your rig to generate some hydro power will complete the triad of solar, wind and hydro.

[Ray Davis]

Someone correct me if I'm wrong here, but our DD engines will run without alternator power, if you have enough battery juice to start?

I lost my alternator in Salt Lake City (first coach), when my A/C compressor froze (right after an A/C service at Prevost). I couldn't put on a replacement belt because the compressor was frozen solid, and I didn't have short belts which would only run the alternator.

But, I successfully drove from SLC, stopped a night in Vegas, and drove into Prevost Mira Loma without issue, or alternator.

Granted, my batteries were not getting any stronger as I went, and I did this within a period of 24 hours. But, I did successfully drive 600+ miles without alternator.


Ray

[Jon Wehrenberg]

Ray is correct. The engine does require electric power, but if the batteries are in good shape, if you conserve the remaining battery power by limiting or not using power robbing devices such as lights, heating and AC systems, mirror heaters, etc. you can travel a considerable distance.

If you have an on-board chassis battery charger you can start the generator and keep your chassis batteries charged.

[0533]

Wind power is handy in that when the sun doesn't shine, it's usually windy.

Peter Byrne of http://www.setantasolar.com/index.php can tell you all you'll ever want to know about solar water heating. He sells the systems and lives the lifestyle. He's waiting for data on my motorhome application.

Using that beautiful little trout stream that runs beside your rig to generate some hydro power will complete the triad of solar, wind and hydro.
Ray, what was determined to be the problem with your alt., had Prevost screwed up and if so what was the cause, I am curious as I had my AC serviced and am seeing some odd battery lights after several days sitting, but have thought it was my chassis batteries not being charged. I now see that the light says 270 alt on it. This has happened twice now and only after my service in Quebec which included a new OTR compressor and a recharge of the system, any clues.

[Ray Davis]

This is a bit of hindsight, and maybe some conjecture. In May of 2006 before heading off on a 1 week trip to Salt Lake City, I thought it would be good to have my A/C's serviced.

I took the bus to Prevost Mira Loma, and serviced the cruise airs, and the Country Coach A/C system. The filled it with R-12.

Well, there was a placard on the system which indicated there was some other refridgerant in the system, not R-12. Will Garner recently indicated the same on his system, it's like R-422 or something. It was very hard to read, I'll admit, but the techs didn't look at that, nor check what was in the current system.

At about 5 hours of use, the compressor completely froze, snapping all belts. My alternator was an external alternator, driven by a belt which also hit the A/C compressor, so when I lost that belt, I lost A/C and alternator at the same time.

Thus began a saga of many months and many thousands of dollars getting that A/C system working again.

So, the alternator was never a "problem", just I couldn't run it due to the A/C compressor being frozen solid.

Ray

[Ray Davis]

am seeing some odd battery lights after several days sitting

Is your equalizer possibly having a problem? The equalizer takes the 24V output from your alternator, and splits it into the two 12V sections of the chassis batteries.

If they are not charging equaly you will get a warning light. My older coach used to say "12/24 volt imbalance". It would flicker on rarely from time to time, but never stayed more than a few seconds.


Ray

[truk4u]

Bruce,

Unless you have something different, you have one 270 amp 24 volt alternator that takes care of both house and chassis when the engine is running. You will have 2 equalizers, one in the engine compartment and another probably adjacent to the house battery bay, because you have series/parallel setups for the chassis and house. Mine was in the battery compartment accessed by a panel. If you have that light coming on, you may have an alternator and/or regulator problem. You need to get it checked out by someone Prevost qualified and not Bubba's Truck Emporium.

[Jon Wehrenberg]

Bruce,

First, you need to know if your coach has one alternator or two. If it has two, you need to determine which is for the house and which is for the chassis. The chassis alternator is the one that is kicking on the warning light.

If the light is temporary, and you have a chassis battery charger, do not try to chase a problem because you will end up being frustrated and if someone tries to solve the problem you will also end up broke. Save your money for Canadian Diesel.

The reason I mention a chassis battery charger is because when the alternator or voltage regualtor finally dies you can maintain a charge on the chassis batteries by running the generator or using shore power to operate the charger until you can get to a service facility. I don't agree with Tom. I would look for the best alternator shop that handles your size alternators. They are experts and likely a lot cheaper than Prevost.

[0533]

I get the 270 alt light on for a few seconds usually about an hour into my first trip after sitting for a while.

I seem to have one alt. 2 equalizers both in the engine compartment, all connections look good, checked them all tight.

I do however get a surge in my fan blower motor at the dash when there is a problem, the amps are at 28 or 29 but I get this pulsing of the blower and it also makes the amp meter its self flicker back and forth.

I am thinking that I may have a bad chassis battery and when I first start up it is not fully charged or balanced, don't really know.

Thanks.

[Jon Wehrenberg]

Bruce....are you talking amps or volts. Nobody can help you if we are not on the same page.

Also, how do you know the blower is what is making the amp meter? flicker back and forth?

One alternator, with two equalizers tells me you may have a 24 volt coach. (I'm talking house here because all our coaches are 24 volt). So what you are calling an amp meter, could it be a volt meter? If so 29 volts is pushing the high side of the range. That suggests to me, if I am able to interpret what you are saying that your alternator could be a problem, but I would not rule out the regulator. In fact if it is voltage and not amps I would monitor voltage very closely. If the regulator or alternator should fail such that you have excess voltage it can have a serious damaging effect on a lot of your devices. An intermittant or occasional glitch is difficult if not impossible to trouble shoot. The pulsing you describe may be the voltage varying and the blower motor reacting to the change in input voltage.

If the voltage gets excessively high (29 volts is at the absolute upper limit from my perspective) I would recommend disabling the alternator. Either disconnect the field wire from the regulator or remove the belt if it does not drive something else.

You can easily check the equalizers and put your mind at ease.

Connect your voltmeter (multi-tester) black lead to a ground (on the equalizer is OK), and read the volts at the 24 volt post and the 12 volt post on the bottom of the equalizer. The equalizer is OK if the 12 volt post is 1/2 of the voltage at the 24 volt post, +/- 1/2 volt.

[truk4u]

I don't agree with Tom

Really! OK, take your bus to Archies Alternator Service and when you open the engine compartments and he say's "Damn, nera seen notin like this, what the hell is those things?" And, "dats the biggest nator I era seen, what the hell is that oil line fur?"

Watch your wallet Bruce...:p

[0533]

Bruce....are you talking amps or volts. Nobody can help you if we are not on the same page.

Also, how do you know the blower is what is making the amp meter? flicker back and forth?

One alternator, with two equalizers tells me you may have a 24 volt coach. (I'm talking house here because all our coaches are 24 volt). So what you are calling an amp meter, could it be a volt meter? If so 29 volts is pushing the high side of the range. That suggests to me, if I am able to interpret what you are saying that your alternator could be a problem, but I would not rule out the regulator. In fact if it is voltage and not amps I would monitor voltage very closely. If the regulator or alternator should fail such that you have excess voltage it can have a serious damaging effect on a lot of your devices. An intermittant or occasional glitch is difficult if not impossible to trouble shoot. The pulsing you describe may be the voltage varying and the blower motor reacting to the change in input voltage.

If the voltage gets excessively high (29 volts is at the absolute upper limit from my perspective) I would recommend disabling the alternator. Either disconnect the field wire from the regulator or remove the belt if it does not drive something else.

You can easily check the equalizers and put your mind at ease.

Connect your voltmeter (multi-tester) black lead to a ground (on the equalizer is OK), and read the volts at the 24 volt post and the 12 volt post on the bottom of the equalizer. The equalizer is OK if the 12 volt post is 1/2 of the voltage at the 24 volt post, +/- 1/2 volt.
Thanks Jon, It must be frustrating to try and talk a challenged POG member through these types of questions.

You must have been a kindergarten teacher in another life.

The meter I am speaking of is the Prevost battery meter in the dash panel.

I will test the equalizer just as soon as I purchase a multimeter and learn how to use it. I think a stop at a NAPA store is in order today. Maybe I need a shopping list. Canada has more NAPA stores than grocery stores.

Truk: When I took the ferry from PEI to NB, and when I was entering the ferry I scraped my genst exhaust dislodging 4 brackets. Went to a really nice truck stop, excellent people, they stopped what they were doing and got right under and fixed the brackets, better than new.

While I was there I asked the manager if they could inspect the altenator and equalizer and see what was up. Well, how did you know that I went to Archies truck shop?? And how did you know what they would say when they opened the engine compartment. "Damn, nera seen notin like this, what the hell is those things?" And, "dats the biggest nator I era seen, what the hell is that oil line fur?"

[Jon Wehrenberg]

Bruce,

I am sure our dash gauges are different, but in my coach my chassis voltage gauge has a needle for voltage and a needle for amps.

Any advice is only as good as the underlying explaination of the problem.

Your issues are exactly what we will be covering in a seminar at Spearfish. The intent of the seminar is not to solve problems, but to help an owner understand exactly what information he should be looking at relative to the electrical systems and how to interpret what is right and what is wrong.

You are jumping before you even realize you are jumping. I make that comment based on the fact you are focusing on equalizers. It's OK to check them, but don't expect any eureka moments. I doubt if they have anything to do with the problem you are trying to describe.

If you have a single alternator, when you are traveling down the road you should see the same voltage for the house that you see for the chassis. Here is where you need to react and get concerned. Depending on the type of house batteries you have, your high voltage (if that is correct) may be hurting your house batteries if they are gel type.

I have not ignored your concerns about chassis batteries going dead. I suspect all of this is tied together, but I just don't know how because there is so much data lacking.

Do you really have just one alternator?
Is your chassis voltage really 29?
Is your house voltage 29 also?
(These are voltage values only with the engine running, but the shore power and generator off)
Do you have a 24 volt house?
Do you have OTR?
Have you physically checked your alternator and regulator connections?
Are your house and chassis battery connections clean and tight?
Have you checked you batteries?
What type house batteries do you have?
Can you get the key off loads on the chassis batteries measured? If the batteries are being depleted there is either a bad battery or a load. That current draw needs to be measured.

The alternator light that is coming on is telling you something. When it comes on if you instantly look at the electrical gauge what are the volts and amps? Are they higher or lower than normal?

What is the chassis battery voltage as measured at the battery posts compared to the dash gauge?

Before focussing on anything it is critical to gather information.