Charging house batterys on the road.

B

Bob Dunahugh

New member
Sep 17, 2012
2,784
4
3
Both of our 78 Royale GMC's had the two position BATT BOOST switch. Not the momentary switch. So did the PO put in the big switch to have a way to connect the two battery sets manually? Seems to me to be a way to discharge all your batteries by inadvertently leaving the manual switch on while parked for a few days.

As to the invertor. During the reconstruction of this Royale. I put in 9 - 110 volt GFI circuits from the gen/shore power. 14 duplex wall plugs. Then a very nice invertor mounted inside a cabinet near the Onan. With two circuits. One down each side. Both circuits have 4 duplex wall plugs. The invertor/ batteries handle her power wheelchair fine. But have never used the invertor for long periods of time on the road. The two batteries in her wheelchair can store a lot of power. But for $730 a pair. They should.

So back to my first question. Why the manual boost switch?

Bob Dunahugh

78 Royale Mouse House.

Member GMCMI

________________________________

Never really thought about it. Just thought that happened as we traveled along. And as I understand. Either the house, or engine battery can get low. So the BATT BOOST switch is for boosting the low battery from the charged battery. The battery charging on the road is now an issue. As there will be at times. That Linda may need 110 volt from the invertor to charge the batteries in her wheelchair as we travel. Because we just don't hit camp grounds much with this 78 Royale anymore. This Royale seems to have been left stock by the PO. Except for a large manual switch that connects the house and engine batteries. So why did the PO put that manual switch in? ( Just made some modifications to have 4 house, and 1 engine battery. 3 up front, 2 in back. ) We all know my sparky issues.

Bob Dunahugh

78 Royale

Member GMCMI.

Iowa
 
>
>
> So back to my first question. Why the manual boost switch?
>
> Bob Dunahugh
> 78 Royale Mouse House.

Bob,

As KenB said, all we can do is guess.

He thought it was a good idea?

In actual fact, both momentary and sustained contact switches make sense....
If it is the sustained contact, you can let the system kill both banks.
If it is momentary and you need to fire the genset from the main engine, it takes two people.

In 10 travel seasons, I have only have only needed to use the boost switch once. That was to get some house lights up because the buzzbox had
destroyed the house battery (then a single 4D).

Even though it is a third level of redundancy, I like that we have three independent 12V system. (We have an APU start battery in the back.) Ma

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
The boost switch's primary purpose is to provide a back up source of energy
to start the coach after depletion of the engine battery from operating
things like the dash radio, and anything else wired into the engine
battery. If you are out in the pucker brush with a flat engine battery, you
will appreciate the boost system. On my coach, I have an identical battery
to the engine battery whose sole purpose is boost. In the rear generator
compartment, I have the house batteries, 2 Trojan 6 volts, and a
progressive dynamics inverter for keeping them charged and providing 120v
power when plugged in. If I want 120 volts when not plugged in, I start the
Onan. Works well for our needs.
Jim Hupy

> >
> >
> > So back to my first question. Why the manual boost switch?
> >
> > Bob Dunahugh
> > 78 Royale Mouse House.
>
> Bob,
>
> As KenB said, all we can do is guess.
>
> He thought it was a good idea?
>
> In actual fact, both momentary and sustained contact switches make
> sense....
> If it is the sustained contact, you can let the system kill both banks.
> If it is momentary and you need to fire the genset from the main engine,
> it takes two people.
>
> In 10 travel seasons, I have only have only needed to use the boost switch
> once. That was to get some house lights up because the buzzbox had
> destroyed the house battery (then a single 4D).
>
> Even though it is a third level of redundancy, I like that we have three
> independent 12V system. (We have an APU start battery in the back.) Ma
>
> Matt
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Still Loving OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Someone sent me a good point by private e-mail on the manual switch. When parked with shore power. Turn the manual switch to connect the engine batteries to the house batteries. This will keep the engine battery up.

Both of our 78 Royale GMC's had the two position BATT BOOST switch. Not the momentary switch. So did the PO put in the big switch to have a way to connect the two battery sets manually? Seems to me to be a way to discharge all your batteries by inadvertently leaving the manual switch on while parked for a few days.

As to the invertor. During the reconstruction of this Royale. I put in 9 - 110 volt GFI circuits from the gen/shore power. 14 duplex wall plugs. Then a very nice invertor mounted inside a cabinet near the Onan. With two circuits. One down each side. Both circuits have 4 duplex wall plugs. The invertor/ batteries handle her power wheelchair fine. But have never used the invertor for long periods of time on the road. The two batteries in her wheelchair can store a lot of power. But for $730 a pair. They should.

So back to my first question. Why the manual boost switch?

Bob Dunahugh

78 Royale Mouse House.

Member GMCMI

________________________________

Never really thought about it. Just thought that happened as we traveled along. And as I understand. Either the house, or engine battery can get low. So the BATT BOOST switch is for boosting the low battery from the charged battery. The battery charging on the road is now an issue. As there will be at times. That Linda may need 110 volt from the invertor to charge the batteries in her wheelchair as we travel. Because we just don't hit camp grounds much with this 78 Royale anymore. This Royale seems to have been left stock by the PO. Except for a large manual switch that connects the house and engine batteries. So why did the PO put that manual switch in? ( Just made some modifications to have 4 house, and 1 engine battery. 3 up front, 2 in back. ) We all know my sparky issues.

Bob Dunahugh

78 Royale

Member GMCMI.

Iowa
 
A better idea that will not depend on you remembering to switch it back is to
install this simple battery combiner. It only takes a few minutes to install.
http://www.appliedgmc.com/prod.itml/icOid/868

http://www.gmcmhphotos.com/photos/frank/p51191-10-minute-combiner-install1.html

bdub

-----Original Message-----
From: Gmclist On Behalf Of Bob Dunahugh
Sent: Sunday, March 12, 2017 7:38 PM

Someone sent me a good point by private e-mail on the manual switch. When
parked with shore power. Turn the manual switch to connect the engine batteries
to the house batteries. This will keep the engine battery up.

Both of our 78 Royale GMC's had the two position BATT BOOST switch. Not the
momentary switch. So did the PO put in the big switch to have a way to connect
the two battery sets manually? Seems to me to be a way to discharge all your
batteries by inadvertently leaving the manual switch on while parked for a few
days.

As to the invertor. During the reconstruction of this Royale. I put in 9 - 110
volt GFI circuits from the gen/shore power. 14 duplex wall plugs. Then a very
nice invertor mounted inside a cabinet near the Onan. With two circuits. One
down each side. Both circuits have 4 duplex wall plugs. The invertor/ batteries
handle her power wheelchair fine. But have never used the invertor for long
periods of time on the road. The two batteries in her wheelchair can store a lot
of power. But for $730 a pair. They should.

So back to my first question. Why the manual boost switch?
 
I have one comment to add about combiners -- perhaps appropriate since I
was one of the earliest promoters of them: After having three Yandina
C100's (formerly known as C50's, with no design/fabrication change) fail, I
applied the third one to a "larger" replacement, the C160. I'm not really
hard on the devices, so I think the C100 is just not up to the GMC's
demands. Go ahead and spend the little extra for the heavier duty device
and save yourself some trouble later -- even if the C100 does come with a
"Lifetime Warranty".
http://yandina.com/

JMHO,

Ken H.

> A better idea that will not depend on you remembering to switch it back is
> to
> install this simple battery combiner. It only takes a few minutes to
> install.
> http://www.appliedgmc.com/prod.itml/icOid/868
>
> http://www.gmcmhphotos.com/photos/frank/p51191-10-minute-
> combiner-install1.html
>
> bdub
 
My converter (battery charger), a Xantrex TruCharge 40, has three output terminals. I use two of them. One goes to the engine battery and one to the house batteries. So both banks are charged independently and both are isolated. There is no need for me to connect the two banks with a boost switch or with a jumper. The TruCharge will not overcharge either bank.

Emery Stora
77 Kingsley
Frederick, CO

>
> Someone sent me a good point by private e-mail on the manual switch. When parked with shore power. Turn the manual switch to connect the engine batteries to the house batteries. This will keep the engine battery up.
>
>
>
> Both of our 78 Royale GMC's had the two position BATT BOOST switch. Not the momentary switch. So did the PO put in the big switch to have a way to connect the two battery sets manually? Seems to me to be a way to discharge all your batteries by inadvertently leaving the manual switch on while parked for a few days.
>
> As to the invertor. During the reconstruction of this Royale. I put in 9 - 110 volt GFI circuits from the gen/shore power. 14 duplex wall plugs. Then a very nice invertor mounted inside a cabinet near the Onan. With two circuits. One down each side. Both circuits have 4 duplex wall plugs. The invertor/ batteries handle her power wheelchair fine. But have never used the invertor for long periods of time on the road. The two batteries in her wheelchair can store a lot of power. But for $730 a pair. They should.
>
> So back to my first question. Why the manual boost switch?
>
> Bob Dunahugh
>
> 78 Royale Mouse House.
>
> Member GMCMI
>
>
>
> ________________________________
>
>
>
> Never really thought about it. Just thought that happened as we traveled along. And as I understand. Either the house, or engine battery can get low. So the BATT BOOST switch is for boosting the low battery from the charged battery. The battery charging on the road is now an issue. As there will be at times. That Linda may need 110 volt from the invertor to charge the batteries in her wheelchair as we travel. Because we just don't hit camp grounds much with this 78 Royale anymore. This Royale seems to have been left stock by the PO. Except for a large manual switch that connects the house and engine batteries. So why did the PO put that manual switch in? ( Just made some modifications to have 4 house, and 1 engine battery. 3 up front, 2 in back. ) We all know my sparky issues.
>
> Bob Dunahugh
>
> 78 Royale
>
> Member GMCMI.
>
> Iowa
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
$300 vs $65
Easy

My converter (battery charger), a Xantrex TruCharge 40, has three output
terminals. I use two of them. One goes to the engine battery and one to the
house batteries. So both banks are charged independently and both are
isolated. There is no need for me to connect the two banks with a boost
switch or with a jumper. The TruCharge will not overcharge either bank.
 
For many years I have read that one should never connect 12 volt batteries in parallel because the weakest one will determine the charge rate of both. Also if one is defective such as a shorted cell it will ruin the other battery.

I have never used a combiner as it seems that it simply connects the two 12 volt banks in parallel when charging just as the boost switch does. The only advantage I see is that it disconnects when shutting off the engine. However If used in the system on the shore charger it connects in parallel as long as you are plugged in and I leave my GMC plugged in all the time when in storage.

Using a battery isolator prevents any problems with parallel connections. You can't use an isolator with a shore charger because of the the voltage drop of the internal diodes. When used with an alternator the alternator voltage regulator increased the charging voltage to compensate for the diode voltage drop.
Using a battery converter / charger with isolated separate charging leads will allow charging of both battery banks but allow each bank to charge at whatever rate it can optimally take.

Yes, it does cost more but I'd like to point out that I just replaced my 2 six volt in-series house batteries and they were dated 3/2008 which means they lasted 9 years. My previous set also lasted over 10 years. So, it may be cheaper to purchase a combiner but in the long run purchasing a "smart" charger with separate charging circuits will actually pay for itself by extending the life of expensive battery sets. It is sometimes short sighted to take the cheap way out if you intend to keep your GMC for a long time. I have owned mine for 36 years now and just replaced my batteries for the third time. I replaced the original 4D house battery with 2 six volt golf cart batteries 33 years ago.

Emery Stora
77 Kingsley
Frederick, CO

>
> $300 vs $65
> Easy
>
>

>
> My converter (battery charger), a Xantrex TruCharge 40, has three output
> terminals. I use two of them. One goes to the engine battery and one to the
> house batteries. So both banks are charged independently and both are
> isolated. There is no need for me to connect the two banks with a boost
> switch or with a jumper. The TruCharge will not overcharge either bank.
 
A combiner is a little smarter than that, and seems to work pretty well.

Another choice, what I did on my old class C is they make a charger that uses one battery to charge the other. But only does so when the first battery is under charge.

But that solution seems even more complex than the combiner.

________________________________
From: Gmclist on behalf of Emery Stora
Sent: Monday, March 13, 2017 7:06:16 AM
To: gmclist
Subject: Re: [GMCnet] Charging house batterys on the road.

For many years I have read that one should never connect 12 volt batteries in parallel because the weakest one will determine the charge rate of both. Also if one is defective such as a shorted cell it will ruin the other battery.

I have never used a combiner as it seems that it simply connects the two 12 volt banks in parallel when charging just as the boost switch does. The only advantage I see is that it disconnects when shutting off the engine. However If used in the system on the shore charger it connects in parallel as long as you are plugged in and I leave my GMC plugged in all the time when in storage.

Using a battery isolator prevents any problems with parallel connections. You can't use an isolator with a shore charger because of the the voltage drop of the internal diodes. When used with an alternator the alternator voltage regulator increased the charging voltage to compensate for the diode voltage drop.
Using a battery converter / charger with isolated separate charging leads will allow charging of both battery banks but allow each bank to charge at whatever rate it can optimally take.

Yes, it does cost more but I'd like to point out that I just replaced my 2 six volt in-series house batteries and they were dated 3/2008 which means they lasted 9 years. My previous set also lasted over 10 years. So, it may be cheaper to purchase a combiner but in the long run purchasing a "smart" charger with separate charging circuits will actually pay for itself by extending the life of expensive battery sets. It is sometimes short sighted to take the cheap way out if you intend to keep your GMC for a long time. I have owned mine for 36 years now and just replaced my batteries for the third time. I replaced the original 4D house battery with 2 six volt golf cart batteries 33 years ago.

Emery Stora
77 Kingsley
Frederick, CO

>
> $300 vs $65
> Easy
>
>

>
> My converter (battery charger), a Xantrex TruCharge 40, has three output
> terminals. I use two of them. One goes to the engine battery and one to the
> house batteries. So both banks are charged independently and both are
> isolated. There is no need for me to connect the two banks with a boost
> switch or with a jumper. The TruCharge will not overcharge either bank.

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
I have replaced several combiners on coaches for customers. Some of them
have a big, unsightly wad of wires that clutter up a compartment that
doesn't need any more clutter. Instructions caution against shortening the
leads. I was taught to make all conductors as short as possible and still
provide strain relief, and to never wad up or wrap them in a circle around
your hand. And, I don't like the little LED lights winking on and off for
purposes I don't fully comprehend. If I further follow my training, I use
the K.I.S.S. principle, parts not actually required, when left out of
assemblies, cause no further service problems. An isolater has no moving
parts, and the three that it does have are extremely robust, and if sized
for the system, last at least as long as the original owners of the
coaches. Just my take on combiners.
Jim Hupy

> A combiner is a little smarter than that, and seems to work pretty well.
>
> Another choice, what I did on my old class C is they make a charger that
> uses one battery to charge the other. But only does so when the first
> battery is under charge.
>
> But that solution seems even more complex than the combiner.
>
> ________________________________
> From: Gmclist on behalf of Emery Stora <
> emerystora>
> Sent: Monday, March 13, 2017 7:06:16 AM
> To: gmclist
> Subject: Re: [GMCnet] Charging house batterys on the road.
>
> For many years I have read that one should never connect 12 volt batteries
> in parallel because the weakest one will determine the charge rate of both.
> Also if one is defective such as a shorted cell it will ruin the other
> battery.
>
> I have never used a combiner as it seems that it simply connects the two
> 12 volt banks in parallel when charging just as the boost switch does. The
> only advantage I see is that it disconnects when shutting off the engine.
> However If used in the system on the shore charger it connects in parallel
> as long as you are plugged in and I leave my GMC plugged in all the time
> when in storage.
>
> Using a battery isolator prevents any problems with parallel connections.
> You can't use an isolator with a shore charger because of the the voltage
> drop of the internal diodes. When used with an alternator the alternator
> voltage regulator increased the charging voltage to compensate for the
> diode voltage drop.
> Using a battery converter / charger with isolated separate charging leads
> will allow charging of both battery banks but allow each bank to charge at
> whatever rate it can optimally take.
>
> Yes, it does cost more but I'd like to point out that I just replaced my 2
> six volt in-series house batteries and they were dated 3/2008 which means
> they lasted 9 years. My previous set also lasted over 10 years. So, it may
> be cheaper to purchase a combiner but in the long run purchasing a "smart"
> charger with separate charging circuits will actually pay for itself by
> extending the life of expensive battery sets. It is sometimes short sighted
> to take the cheap way out if you intend to keep your GMC for a long time. I
> have owned mine for 36 years now and just replaced my batteries for the
> third time. I replaced the original 4D house battery with 2 six volt golf
> cart batteries 33 years ago.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>

> >
> > $300 vs $65
> > Easy
> >
> >

> >
> > My converter (battery charger), a Xantrex TruCharge 40, has three output
> > terminals. I use two of them. One goes to the engine battery and one to
> the
> > house batteries. So both banks are charged independently and both are
> > isolated. There is no need for me to connect the two banks with a boost
> > switch or with a jumper. The TruCharge will not overcharge either bank.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
I have one comment to add about combiners -- perhaps appropriate since I
was one of the earliest promoters of them:  After having three Yandina
C100's (formerly known as C50's, with no design/fabrication change) fail, I
applied the third one to a "larger" replacement, the C160.  I'm not really
hard on the devices, so I think the C100 is just not up to the GMC's
demands.  Go ahead and spend the little extra for the heavier duty device
and save yourself some trouble later -- even if the C100 does come with a
"Lifetime Warranty".
http://yandina.com/

JMHO,

Ken H.
 
To reinforce a little of what Emory said. I have seen several batteries that have blown up. The only one that I was around when it actually blew was
in Roger Black's coach at a GMCMI rally. It blew up in the middle of the night. Besides Roger, it woke up me and several others in coaches nearby.
For this and seeing the damage on others after the fact, reasons I never parallel lead acid, L-ion or nicad batteries.

In another application I had three 8 amp/hour batteries on a 6 amp charger wired in parallel when one shorted. I had intentionally used thin 18 gauge
wire when I hooked them up. It was good that I did because when one shorted, it burned the wire in half rather than blowing up from over current.

In the last year I have had two different lead acid batteries short one cell. One was in my John Deere and one was in my daughters motorcycle.
Neither were wired in parallel with anything and so they did not blow up.

If you insist on paralleling lead acid batteries, I suggest that you put some kind of current limiting device between them. Since batteries seldom
charge at over 30 amps, a 40 or 50 amp circuit might so the trick. GM used a 50 amp CB for rear mounted house batteries.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
http://www.defender.com/pdf/204578_Yandina.pdf

That only means that the device is no longer combining the batteries. They have either equalized or the charger has stopped working.

Have installed 3 of them over the years and they all continue to work as advertised. Even one that I cracked the case on.

(knocking on wood) ;-)
bdub

-----Original Message-----
From: Gmclist On Behalf Of THOMAS R WHITTON
Sent: Monday, March 13, 2017 9:52 AM

Ken,
The green LED light on my C50 combiner comes on when I first connect the batteries (I disconnect them while the coach is parked in the garage). Then, after some time has passed, I notice the LED has gone off. Is this normal or is it telling me the combiner has failed?
Thanks,Tom Whitton26 foot updated GMCPaducah, KY

Date: Sun, 12 Mar 2017 22:39:21 -0400
From: Ken Henderson

I have one comment to add about combiners -- perhaps appropriate since I was one of the earliest promoters of them: After having three Yandina C100's (formerly known as C50's, with no design/fabrication change) fail, I applied the third one to a "larger" replacement, the C160. I'm not really hard on the devices, so I think the C100 is just not up to the GMC's demands. Go ahead and spend the little extra for the heavier duty device and save yourself some trouble later -- even if the C100 does come with a "Lifetime Warranty".
http://yandina.com/
 
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