Class C coach battery and Generator

I have a 1990 Itasca class 'c' . My question is if your are dry camping and are using your genset to run the coach ie AC, microwave etc. . At night so you dont have to hear the genset and just need the coach battery for water pump lights, does the converter switch it automatically or is their  a manual way of doing this. I know the new RV's have a switch to do this, but how about the older ones. BTW the batteries is getting charged from the genset and is working properly. I did search but didnt find any solid answers to this issue. Thank you for the help.

You are mixing and misusing terminology here.  You probably don't even have an INverter.

The CONverter does charge your house battery when the generator is running (or when you are plugged to shore power).  There is NO switching required to run the lights and water pump from the batteries when you stop the generator.  It is automatic.

Most class A's do have a switch (battery disconnect) to prevent many things from drawing current from the batteries, but I'm not shure if that is common on Class Cs or not.  My old '85 Tioga, did not.

03 cobra sb said:

I have a 1990 Itasca class 'c' . My question is if your are dry camping and are using your genset to run the coach ie AC, microwave etc. . At night so you dont have to hear the genset and just need the coach battery for water pump lights, does the inverter switch it automatically or is their  a manual way of doing this. I know the new RV's have a switch to do this, but how about the older ones. BTW the batteries is getting charged from the genset and is working properly. I did search but didnt find any solid answers to this issue. Thank you for the help.

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I think that your question is, "does the converter switch it automatically or is their  a manual way of doing this?"

The 12V items in your coach always run off of your batteries. The converter is in play while plugged into shore power and running your genset. Basically, the converter just keeps your battery from running down while using your 12V items......... so the answer to your question is, "Yes your converter is automatic (for all intents and purposes)".




**** oops "Just Lou" beat me to it....... ;D

  I believe on that vintage of coaches the converter does just that - it converts a portion of the A/C to DC as it comes in from shore power or from your generator. That is why it is called a converter. And it is my understanding that is where the DC items in your coach get their power - at that time. When you turn the generator off or unplug from shore power, the battery takes over and supplies DC to the coach.

Your converter also has a battery charger built into it. So the converter really isn't charging the batteries. The charger in the converter is charging the batteries. When on genset or shore power, it charges your batteries automatically - as you have indicated happens.

Bob Buchanan said:

  I believe on that vintage of coaches the converter does just that - it converts a portion of the A/C to DC as it comes in from shore power or from your generator. That is why it is called a converter. And it is my understanding that is where the DC items in your coach get their power - at that time. When you turn the generator off or unplug from shore power, the battery takes over and supplies DC to the coach.

Your converter also has a battery charger built into it. So the converter really isn't charging the batteries. The charger in the converter is charging the batteries. When on genset or shore power, it charges your batteries automatically - as you have indicated happens.

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I don't believe that is accurate.  The converter has only one part to it that converts 110V to 13.2V-13.8V on that older rig. It has a single transformer that does the conversion and that transformer is a lousy battery charger that tops out @ ~13.8V.

The later model converters have actual 3-stage battery chargers in them. If there is no battery in the coach and the only demand is lights and 12V appliances, the converter will stay at 13.2V (just like the old ones). If there is a battery connected to it, the converter senses the load from the battery and will charge the battery accordingly (in stages) but the 12V lights and appliances are still running off that one source.

Be careful there Wayne.  While Bob's description of early converters, and their operational characteristics, was common at the time for some manufacturers, it was by no means "the standard". 

With that said, I'm going to predict that the technical gurus here will could point out more "inaccuracies" in your narrative than in Bob's.

Just Lou said:

Be careful there Wayne.  While Bob's description of early converters, and their operational characteristics, was common at the time for some manufacturers, it was by no means "the standard". 

With that said, I'm going to predict that the technical gurus here will could point out more "inaccuracies" in your narrative than in Bob's.

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That's what the forum is all about... right??

If one person posts an inaccuracy, that stimulates discussion..... ;D ..... No harm, no foul..... unless someone is really thin skinned. It wouldn't be the 1st time that I was corrected on this forum. That's what makes it a great forum.  ;D

Actually, after reading Bob's post again, I think that he may have meant to say, "Your generator also has a battery charger built into it."..... If that's the case, it was a simple typo and I agree with his post..... I just couldn't figure it out at 1st....

Now you've really lost me.  I've never seen an on-board generator with a built in battery charger.

BTW - I was just trying, unskillfully evidently, to lightheartedly point out some possible discrepancies in your description of both the older and the newer converter chargers in use today.

Wavery said:

Actually, after reading Bob's post again, I think that he may have meant to say, "Your generator also has a battery charger built into it."..... If that's the case, it was a simple typo and I agree with his post..... I just couldn't figure it out at 1st....

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    The genset had nothing to do with the charging - other than when turned on supplies the AC for the charger portion of those old magnatek converters. If on shore power, that is where the charger gets it's AC. Charging in those days of converting was not as part of the converted AC to DC. Again, it was always my understanding that when on shore or genset, the major portion of the AC went to the Coach AC needs and the rest was converted to DC for the coaches DC needs. None of it went to the battery.  And part of the AC powered the charger that was built into the converter.

The chargers were not very good other than to boil batteries. Magantek has mulit stage replacement charging units. My earliest experience was with a '94 - so perhaps they were different in '90. I have had that converter type in 4 rigs. Each time I have disabled the charger portion (ususally via a breaker) and installed my 40amp Statpower 3 stage charger and a separate inverter on a bulkhead close to the batteries.

I also understand that the converted DC in newer units "is" part of the charging scenario.

If one person posts an inaccuracy, that stimulates discussion..... ;D ..... No harm, no foul..... unless someone is really thin skinned. It wouldn't be the 1st time that I was corrected on this forum. That's what makes it a great forum.  ;D

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Agreed!!!   

What confused me was this statement,"So the converter really isn't charging the batteries. The charger in the converter is charging the batteries." 

There is only 1, 110V to 12V conversion taking place in the converter. it converts 110V to 13.?V and sends that 13.?V current to the fuse bus. From there, it goes to the house circuits and battery ........ maybe I'm just not getting what you meant.  ??? and the OP is probably totally confused by now because it really doesn't matter. The bottom line is, the converter charges the batteries and powers the house while the genset is running or on shore power.....

Bob Buchanan said:

  I believe on that vintage of coaches the converter does just that - it converts a portion of the A/C to DC as it comes in from shore power or from your generator. That is why it is called a converter. And it is my understanding that is where the DC items in your coach get their power - at that time. When you turn the generator off or unplug from shore power, the battery takes over and supplies DC to the coach.

Your converter also has a battery charger built into it. So the converter really isn't charging the batteries. The charger in the converter is charging the batteries. When on genset or shore power, it charges your batteries automatically - as you have indicated happens.

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I wanted to hear what others have with the older coaches. Everything works except the auto transfer back to the coach battery. Trying to figure out if I have a bad converter.

03 cobra sb said:

I wanted to hear what others have with the older coaches. Everything works except the auto transfer back to the coach battery. Trying to figure out if I have a bad converter.

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You probably have a blown fuse or bad circuit breaker. Do all of your lights work off the battery without any 110V input (either from shore power or generator)?
BTW...... on the older models, you may have a fuse right at the battery for your house current. Is your house battery mounted in the coach or in the engine compartment?

Wavery said:

What confused me was this statement,"So the converter really isn't charging the batteries. The charger in the converter is charging the batteries." 

There is only 1, 110V to 12V conversion taking place in the converter. it converts 110V to 13.?V and sends that 13.?V current to the fuse bus. From there, it goes to the house circuits and battery ........ maybe I'm just not getting what you meant.  ??? and the OP is probably totally confused by now because it really doesn't matter. The bottom line is, the converter charges the batteries and powers the house while the genset is running or on shore power.....

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Not sure how I could word that more clearly, Wayne. The converter converts a portion of the incoming AC to DC. And, yes, it goes to the house circuits and fuse panel. But in those units, it did not go to the battery. You say it does, I say, IMO, it doesn't. My statement, "So the converter really isn't charging the batteries. The charger in the converter is charging the batteries." is about a clear as I can state that to you.

Do you understand that as part of that converter there was/is a battery charger built in?  It is powered by AC from either the genset or shorepower. You seem to be writing that the batteries are charged by a portion of the converted DC - and not as part of an AC powered charger. Is that the case?

You've written that what I posted may be inaccurate, commented that I must have meant something else, and now that I am confusing you. So am just trying to figure exactly what it is that I have written that is inaccurate.

03 cobra sb said:

I have a 1990 Itasca class 'c' . My question is if your are dry camping and are using your genset to run the coach ie AC, microwave etc. . At night so you dont have to hear the genset and just need the coach battery for water pump lights, does the converter switch it automatically or is their  a manual way of doing this. I know the new RV's have a switch to do this, but how about the older ones. BTW the batteries is getting charged from the genset and is working properly. I did search but didnt find any solid answers to this issue. Thank you for the help.

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The genset isn't charging the batteries. IMO, (and Wayne and I disagree on this), if you have the same converter that I have had in a '94 Winny and a '96 Winny, the batteries are charged by the AC powered charger that is built into your converter. So whenever you run the genset, that charger is charging the batteries.

When you turn off the genset, the switching from the converted AC to DC running your DC lights and such to getting their DC from the batteries should happened automatically. If your batteries are still a bit down when you shut down the genset, the lights will usually go from very bright to much dimmer. That is because the converter supplied DC is much stronger than what is left in the batteries when the switch is complete.

You write that the batteries are charging OK, but also asking how to switch to the batteries - so, for example, when you turn off the genset, do the DC lights stay on? If so, the auto switch worked, or, is everything dead DC wise when you turn off the genset?

Bob Buchanan said:

Do you understand that as part of that converter there was/is a battery charger built in?

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I was not aware of that...... I have replaced the transformer in a few of those old converters (many years ago). I haven't seen one with 2 separate transformers but I suppose they could exist. I just can't imagine why.

Bob Buchanan said:

It is powered by AC from either the genset or shorepower. You seem to be writing that the batteries are charged by a portion of the converted DC - and not as part of an AC powered charger. Is that the case?

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That is the only way that I have ever seen the older ones operate. The converter puts out 13.?V and voltage goes to a single positive buss bar. On that buss bar is a terminal that goes to the battery. When the coach has AC power, that power goes to a circuit breaker for the converter. When that breaker has power, it goes to the converter which converts AC to DC which then goes directly to the same buss bar that the battery is connected to. The converter barely puts out enough voltage to keep a full battery charged (on the ones that I've seen) but is more than adequate to keep the lights on. When there is no current coming from the converter, the battery is the source for DC current.... no switching involved on most although I have seen some with switches........ that's on the old ones that I worked on.... not saying all of them.

I have seen solid state converters where thee is a separate charging circuit.

My statement was, "I don't believe that is accurate."....... that was not meant as an insult or attack on anyone....... it was a statement of what I believe is accurate as to my personal experience. As I later stated.... "It wouldn't be the 1st time that I was corrected on this forum. That's what makes it a great forum.  ;D"
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Bob Buchanan said:

The genset isn't charging the batteries. IMO, (and Wayne and I disagree on this),

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Actually we don't disagree on it. I just thought that it may have been a typo, which you later explained it wasn't....... I do know that some old gensets have a separate 12V charging circuit...... didn't think that was the case here but just didn't know.... ;D

The 6300 series converter/charger most certainly had 2 different  actions, with 2 different output voltages. I just took one out of my 95 Challenger, and went with a 9260 which is claimed to have 4 modes. The output is determined by battery voltage according to the manual that came with it.

92GA said:

The 6300 series converter/charger most certainly had 2 different  actions, with 2 different output voltages. I just took one out of my 95 Challenger, and went with a 9260 which is claimed to have 4 modes. The output is determined by battery voltage according to the manual that came with it.

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Here's the guts to a 6300 that I replaced for a friend a few years ago...... Only one transformer. One set of wires going to the 12V bus bar.

I took out the "Converter" portion and installed a Progressive Dynamics converter with a 3-stage smart charger.....

"What we have here, is failure to communicate."

Sometimes specifics can be as misleading as generalities.

As you will see from the attached diagram, the 63xx Magnetek has ONE AC to DC converter (the transformer and associated rectifier diode pack).  It does/did have two outputs.

• One output fed the DC (converted AC directly to the fuse/distribution panel.
• The DC was also directed to a requlated  and adjustable section (the charger section) and on to the batteries.

One converter, two outputs.

The OP should note that his vintage converter/charger would have only one relay on the output stage (not two) which provides the single point of failure he is apparantly seeing.

IF his batteries are being charged from the converter/charger, BUT the batteries are not being connected to the distribution panel when the rig is unplugged, I would say that relay (RY1) is not making the connection through it's n/c contacts.

Sorry about the double post of the diagram in the previous reply.

For the benefit of 92GA, the two outputs of the 63XX should in no way be confused with, or compared to, the multiple charging stages of the PD9260.