| Another question form the new guy [message #195114] |
Mon, 07 January 2013 22:52  |
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SteveW
Messages: 538
Registered: June 2005
Location: Southern California - Ora...
Karma: 1
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Senior Member |
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Greetings Everyone -
THANK YOU again for providing your experience and expertise. This place makes me very pleased that I chose a GMC Motorhome.
So I was working on the coach this weekend - examining things in preparation of replacing/upgrading the AC/DC electronics. Converter/charger, an inverter, and new 12V fuses...
I have two batteries up in the engine compartment - chassis and house. I expected to find a third battery back by the generator - a house battery - and plan to connect the inverter there. With that - it's a 5 foot cable run to nicely route cables to an inverter in the same cabinet as the existing electronics.
Well... I dug into the rear of the coach and was pleasantly surprised to discover two batteries back there!! 2 x 12V connected in parallel. And nicely installed too. Firmly held with a tiedown made from a piece of unistrut. Here's the questions:
I expected one battery back there... Was the factory configuration a single battery ?? What did the PO remove to squeeze a second battery in ??
I expect that two six volt batteries in series is the preferred configuration. Is there any reason that I should be concerned rather than pleasantly surprised ??
How does this affect my selection of a Progressive dynamics Converter/Charger ?? 45 amp or 60 amp or even larger ??
How does this affect any battery combiners that I've also been planning to install ??
I assume (didn't check yet) that these two batteries are also in parallel with the house battery up front. My memory certainly isn't the thing to rely on - but I sure don't recall seeing any heave guage cables connecting to the house battery up front. Could they be connected some other way ??
As from a previous posting - the chassis battery, the up front house battery, and this battery pack each have cut off switches on the negative terminals.
I've got endless questions - but that enough for tonight. Thanks again.
Steve W
Southern California
1973 23'
Steve W
1973 : 23'
Southern California
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| Re: [GMCnet] Another question form the new guy [message #195118 is a reply to message #195114] |
Tue, 08 January 2013 00:21  |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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Steve,
We have found that your always better ahead if you use 2 6volt Deep Cycle
batteries in series.
For some reason, hooking two 12 volt units in series develop a problem when
one cell weakens and it will cause the other to drain.
On Mon, Jan 7, 2013 at 8:52 PM, Steve Weinstock <steve.weinstock@cox.net>wrote:
>
>
> Greetings Everyone -
>
> THANK YOU again for providing your experience and expertise. This place
> makes me very pleased that I chose a GMC Motorhome.
>
> So I was working on the coach this weekend - examining things in
> preparation of replacing/upgrading the AC/DC electronics.
> Converter/charger, an inverter, and new 12V fuses...
>
> I have two batteries up in the engine compartment - chassis and house. I
> expected to find a third battery back by the generator - a house battery -
> and plan to connect the inverter there. With that - it's a 5 foot cable
> run to nicely route cables to an inverter in the same cabinet as the
> existing electronics.
>
> Well... I dug into the rear of the coach and was pleasantly surprised to
> discover two batteries back there!! 2 x 12V connected in parallel. And
> nicely installed too. Firmly held with a tiedown made from a piece of
> unistrut. Here's the questions:
>
> I expected one battery back there... Was the factory configuration a
> single battery ?? What did the PO remove to squeeze a second battery in ??
>
> I expect that two six volt batteries in series is the preferred
> configuration. Is there any reason that I should be concerned rather than
> pleasantly surprised ??
>
> How does this affect my selection of a Progressive dynamics
> Converter/Charger ?? 45 amp or 60 amp or even larger ??
>
> How does this affect any battery combiners that I've also been planning to
> install ??
>
> I assume (didn't check yet) that these two batteries are also in parallel
> with the house battery up front. My memory certainly isn't the thing to
> rely on - but I sure don't recall seeing any heave guage cables connecting
> to the house battery up front. Could they be connected some other way ??
>
> As from a previous posting - the chassis battery, the up front house
> battery, and this battery pack each have cut off switches on the negative
> terminals.
>
> I've got endless questions - but that enough for tonight. Thanks again.
>
> Steve W
> Southern California
> 1973 23'
>
>
>
>
>
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
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Unsubscribe or Change List Options:
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Another question form the new guy [message #195124 is a reply to message #195114] |
Tue, 08 January 2013 02:09 |
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ljdavick
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
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Senior Member |
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Steve,
I sent the Battery Balance article to you off net, as I don’t remember where to find the link. This was an article in the FMCA magazine, and I thought it did an excellent job of explaining balancing 12 volts among multiple batteries.
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, CA
On Jan 7, 2013, at 8:52 PM, Steve Weinstock wrote:
>
>
> Greetings Everyone -
>
> THANK YOU again for providing your experience and expertise. This place makes me very pleased that I chose a GMC Motorhome.
>
> So I was working on the coach this weekend - examining things in preparation of replacing/upgrading the AC/DC electronics. Converter/charger, an inverter, and new 12V fuses...
>
> I have two batteries up in the engine compartment - chassis and house. I expected to find a third battery back by the generator - a house battery - and plan to connect the inverter there. With that - it's a 5 foot cable run to nicely route cables to an inverter in the same cabinet as the existing electronics.
>
> Well... I dug into the rear of the coach and was pleasantly surprised to discover two batteries back there!! 2 x 12V connected in parallel. And nicely installed too. Firmly held with a tiedown made from a piece of unistrut. Here's the questions:
>
> I expected one battery back there... Was the factory configuration a single battery ?? What did the PO remove to squeeze a second battery in ??
>
> I expect that two six volt batteries in series is the preferred configuration. Is there any reason that I should be concerned rather than pleasantly surprised ??
>
> How does this affect my selection of a Progressive dynamics Converter/Charger ?? 45 amp or 60 amp or even larger ??
>
> How does this affect any battery combiners that I've also been planning to install ??
>
> I assume (didn't check yet) that these two batteries are also in parallel with the house battery up front. My memory certainly isn't the thing to rely on - but I sure don't recall seeing any heave guage cables connecting to the house battery up front. Could they be connected some other way ??
>
> As from a previous posting - the chassis battery, the up front house battery, and this battery pack each have cut off switches on the negative terminals.
>
> I've got endless questions - but that enough for tonight. Thanks again.
>
> Steve W
> Southern California
> 1973 23'
>
>
>
>
>
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
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| Re: Another question form the new guy [message #195127 is a reply to message #195114] |
Tue, 08 January 2013 05:11 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
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Senior Member |
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| SteveW wrote on Mon, 07 January 2013 20:52 |
...
I have two batteries up in the engine compartment - chassis and house. I expected to find a third battery back by the generator - a house battery - and plan to connect the inverter there. With that - it's a 5 foot cable run to nicely route cables to an inverter in the same cabinet as the existing electronics.
Well... I dug into the rear of the coach and was pleasantly surprised to discover two batteries back there!! 2 x 12V connected in parallel. And nicely installed too. Firmly held with a tiedown made from a piece of unistrut. Here's the questions:
I expected one battery back there... Was the factory configuration a single battery ?? What did the PO remove to squeeze a second battery in ?? ...
...
Steve W
Southern California
1973 23'
|
I see that you have a 23 foot 1973 coach. From your description, there have been LOTS of changes from the time you coach left the factory.
The following is for reference:
From the factory, 1973 and 1974 coaches had three batteries. Two automotive "starting" type batteries up front. One was used to start the engine and power the automotive circuits. The other "starting" battery was connected to the house circuits, including the buzz box converter. Both of these front mounted batteries where connected to an isolator so the engine alternator charged both when the motor was running. They also where connected to a single "boost" solenoid, allowing the house battery to help start the engine battery.
The third battery, mounted in the rear, was NOT electrically connected to the others in anyway. It was also the only way to start the generator. As it was charged ONLY by the flywheel alternator of the genset, and the gensets where not used very often, the rear battery often found dead. The exact location of this rear mounted battery was in different places depending on the length of the coach. A 26 foot coach the battery was found to the rear of the genset accessed from the same side hatch as the generator. The battery on the 23 foot version (like your's) was mounted just forward on the generator compartment, just inboard of the driver's side wheel-well. This battery was accessed from a hatch INSIDE the coach.
Now that you have this information, you'll understand why I ask this question: Where did they find the room in a 23 foot coach for TWO 12 volt batteries? Pictures would be good! 
If you can not figure out the changes to your coach, you'd be better off finding someone local to eye-ball your set-up and help you figure it out.
Bottom line, there has been so many changes to your coach you really can not get very much SPECIFIC information on YOUR coach from the Internet. Much general info though....
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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| Re: Another question form the new guy [message #195158 is a reply to message #195155] |
Tue, 08 January 2013 09:21 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
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Senior Member |
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| mgrue wrote on Tue, 08 January 2013 06:38 |
Although the prevailing wisdom is to use 6 volt batteries in series, I have been using two 12 volt truck batteries in parallel in the coach for 2 years. ...
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I do not think many will tell you that 12volt batteries in parallel will NOT work... because quite obviously it does. ..."work" that is.
BUT they are correct that the possible problems are much more likely with paralleled systems.
Besides having batteries closely matched in type construction and age, one of the tricks to making it work is making it "balanced" as possible so that each battery "sees" the same electrical load and charge. You need to really think about cable size, length and routing. The more banks and distance between the batteries, the more issues you'll have.
The less "balanced" your battery banks the less performance in life and capacity you'll have.
Simpler, and the most bang for the buck, is to put two golf cart 6v batteries in series making a single 12v bank with the capacity needed for most mild boon-docking needs.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
[Updated on: Tue, 08 January 2013 09:44] Report message to a moderator |
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| Re: [GMCnet] Another question form the new guy [message #195201 is a reply to message #195118] |
Tue, 08 January 2013 13:50 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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| jimk wrote on Tue, 08 January 2013 00:21 |
Steve,
We have found that your always better ahead if you use 2 6volt Deep Cycle batteries in series.
For some reason, hooking two 12 volt units in series develop a problem when one cell weakens and it will cause the other to drain.
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Also hooking two 12 volt batteries in series causes a lot or smoke.
Jim meant to say hooking two 12 volt batteries in parallel.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Another question form the new guy [message #195256 is a reply to message #195114] |
Tue, 08 January 2013 23:51 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
Karma: 0
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Senior Member |
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You can put as many 12v batteries as you like in series just not for this application!
6V batteries tend to have a advantage of heavier plates. They are designed to be discharged deeper and recharged over and over. Which is great for RV use. They don't lose voltage as easy as they discharge. 12v batteries tend to have less ability to cycle as well, but they work just fine. If you hooking them both up make sure they are the same date code, installed at the same time, and of equal spec.
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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