GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » [GMCnet] How to conect two 12 volt battery banks DROBO for batteries?
[GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230717] Thu, 21 November 2013 20:32 Go to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
Thinking about my Sister-in-law's off-grid home made me think of the GMC (it often does). Many on the list have multiple 12 volt battery banks that are connected in parallel. I know that paralleling batteries can be bad, so I began to wonder if any intelligent soul has developed a "combiner / isolator" that would allow all banks to act isolated 12 volt batteries - charge and draw power as needed, combining all banks when needed for big power draws. I can't be the first to think of this, but Google hides this secret from me.

It's analogous to computer hard drives in a storage array. Back-when, to make a terabyte array you would combine similar disks (same manufacturer, model, etc.), into a raid array to gain the capacity needed (excepting for the loss of the checksum data.) Drobo set the low-cost RAID world on it's ear by making a device that would take ANY SATA drive and allow you to toss it in the mix. As the array fills up you replace the smallest disk. I simplify, but you get the idea.

It seems to me this kind of device would be very practical when you want to add a bit more capacity without replacing the entire battery bank. It would also allow for old weak batteries to be used much longer as they won't draw down the other banks. Imagine the Ragusa trays filled with batteries. Aside from a 20,000 lb. coach it would be nice to boon-dock, or run a bigger inverter as needed.

Any thoughts about living HUGE in a GMC? Am I making too much of the paralleled battery issue?

Larry Davick
Fremont, California
A Mystery Machine
'76 (ish) Palm Beach
_______________________________________________
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
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230718 is a reply to message #230717] Thu, 21 November 2013 20:53 Go to previous messageGo to next message
bwevers is currently offline  bwevers   United States
Messages: 597
Registered: October 2010
Location: San Jose
Karma: 5
Senior Member
Larry,
Read here:
http://www.yandina.com/combInfo.htm#Q12

It says that you add a combiner for each bank.
When you figure it out, please explain it to me. Laughing

-Bill


Bill Wevers GMC49ers, GMC Western States 1975 Glenbrook - Manny Powerdrive, OneTon 455 F Block, G heads San Jose
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230719 is a reply to message #230717] Thu, 21 November 2013 20:57 Go to previous messageGo to next message
bwevers is currently offline  bwevers   United States
Messages: 597
Registered: October 2010
Location: San Jose
Karma: 5
Senior Member
Found this statement:

"The Combiner 100 is a voltage-sensing relay (13.3 volts) which connects two batteries together when either is receiving a charge. When the charging ceases, the relay opens so that each battery operates independently. Supplemental battery banks can be added by using an additional combiner for each bank. You never have to worry about switching to "BOTH" when your engine is running and forgetting to switch back to save your starting battery from discharge when you stop."

It combines when charging, but not when you put a load on it.


Bill Wevers GMC49ers, GMC Western States 1975 Glenbrook - Manny Powerdrive, OneTon 455 F Block, G heads San Jose
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230720 is a reply to message #230717] Thu, 21 November 2013 21:11 Go to previous messageGo to next message
bwevers is currently offline  bwevers   United States
Messages: 597
Registered: October 2010
Location: San Jose
Karma: 5
Senior Member
Here's a 3 battery boat set-up. But you have to manually
switch between battery banks:
http://www.cmsquick.com/schematic-e.jpg


Bill Wevers GMC49ers, GMC Western States 1975 Glenbrook - Manny Powerdrive, OneTon 455 F Block, G heads San Jose
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230722 is a reply to message #230720] Thu, 21 November 2013 21:29 Go to previous messageGo to next message
tphipps is currently offline  tphipps   United States
Messages: 3005
Registered: August 2004
Location: Spanish Fort, AL
Karma: 9
Senior Member
If I'm following the 3 battery boat diagram, you have 3 different load paths from the battery; engine, house, refrig.
If the goal is to build a large storage capacity, would it not be better to use larger capacity batteries, ignoring for the moment their weight and physical size as individual units? Might be interesting to see a diagram of the battery banks installed in all-electric vehicles. They must have computers dedicated to battery charge controlling.
I would series connect individual banks of 6v batteries, to control weight distribution and ease of servicing. Robin has a defective large 12v battery in his Barn Queen that I'm not sure I could move very readily. I know it is in the door way, and you have to step around or over it. ( it is not connected. I suspect it is dead.)

Tom, MS II


2012 Phoenix Cruiser model 2552 KA4CSG
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230724 is a reply to message #230718] Thu, 21 November 2013 23:18 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
I understand the combiner to charge the batteries, but what if you want to draw a big load where all banks should be connected as one big battery?
Splitting the batteries up by function might work, but what if you want to run the microwave where all batteries would make sense?

Larry Davick

> On Nov 21, 2013, at 6:53 PM, Bill Wevers <gmc1975@att.net> wrote:
>
>
>
> Larry,
> Read here:
> http://www.yandina.com/combInfo.htm#Q12
>
> It says that you add a combiner for each bank.
> When you figure it out, please explain it to me. :lol:
>
> -Bill
> _______________________________________________
> 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
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230725 is a reply to message #230717] Thu, 21 November 2013 23:31 Go to previous messageGo to next message
Bullitthead is currently offline  Bullitthead   United States
Messages: 1411
Registered: November 2013
Karma: 5
Senior Member
You can use isolators to keep the batteries seperated while charging and at rest. Then you can use the early Ford starter relays to connect them together for a large current draw. The relays draw power when switched on, but they don't have to be controlled by the batteries they are connecting together. Switching the relays on could be manually controlled or automatically done when the large load is engaged. Hundreds of possibilities and wiring setups based on power needs and the size of your checkbook!

That way you don't have to get out and flip a knife switch at the battery terminals when you need the extra current from multiple batteries.


Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230732 is a reply to message #230725] Fri, 22 November 2013 00:36 Go to previous messageGo to next message
appie is currently offline  appie   Denmark
Messages: 902
Registered: April 2013
Location: denmark
Karma: 2
Senior Member
that is what this combiner does, it also has a booster build in

http://www.victronenergy.com/battery-isolators-and-combiners/cyrix-120a-225a-425a/


Appie eleganza 76 "Olga" now sadly sold 6 wheel discbrake Quadrabags Springfield stage 2 462 olds Manny tranny ( pictures at http://www.gmcmhphotos.com/photos/g6489-olga.html Fulltiming in Europe july 2014 til july 2016 Denmark

[Updated on: Fri, 22 November 2013 00:57]

Report message to a moderator

Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230736 is a reply to message #230732] Fri, 22 November 2013 00:56 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
Appie,

I think the combiner only handles the charging side, not the load (or draw) side.

I want all the power when I need it but none of the problems of parallel batteries.

Larry Davick

> On Nov 21, 2013, at 10:36 PM, lenze middelberg <lenze@middelberg.dk> wrote:
>
>
>
> that is what this combiner does, it also has a booster build in
>
> http://www.victronenergy.dk/battery-isolators-and-combiners/cyrix-120a-225a-425a/
> --
> Appie
> eleganza 76 "Olga" ( pictures at https://picasaweb.google.com/101021920836990233644/GMCMHOlga02)
> Volvo v70
> Denmark
> _______________________________________________
> 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
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230737 is a reply to message #230732] Fri, 22 November 2013 01:31 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
I read the data sheets of both the Cyrix-1 200A 400A and the Cyrix-1 12/24 120A 225A units. I "think" that they will do what you are asking.

I also had a thought of designing something with a primary battery being on line all the time with some voltage sensing attached to it. If the voltage on the primary battery dropped below a given level line like 12 or 12.2 volts, a relay would pick up and a second battery would come on line in parallel with the first one. This could be expanded with additional voltage sensing and relays for each additional battery that one wishes to install.

Some safeguards would have to be placed in the circuit to prevent a shorted battery from being switched into the online bank.

I would have to think it out some more before I would call it safe.

Doable, I think so. Necessary, I do not know.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230739 is a reply to message #230737] Fri, 22 November 2013 02:00 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
Ken,

I think that Peurket's law makes a case for your design. If I understand it correctly a big load (relative to the battery capacity) diminishes the total amour of energy available from a battery.

Something like - If you draw 200 watts from a given battery in 10 minutes it may deplete the battery. If you draw 200 watts over 20 hours the battery may still have 20% capacity left.

<http://en.m.wikipedia.org/wiki/Peukert's_law>

Therefore a larger capacity battery may be better for big loads.

I'm not familiar with the Cyrix units. I'll read up on the links.

Larry Davick
_______________________________________________
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
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230742 is a reply to message #230739] Fri, 22 November 2013 02:15 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
ljdavick wrote on Fri, 22 November 2013 02:00

Ken,

I think that Peurket's law makes a case for your design. If I understand it correctly a big load (relative to the battery capacity) diminishes the total amour of energy available from a battery.

Something like - If you draw 200 watts from a given battery in 10 minutes it may deplete the battery. If you draw 200 watts over 20 hours the battery may still have 20% capacity left.

<http://en.m.wikipedia.org/wiki/Peukert's_law>

Therefore a larger capacity battery may be better for big loads.

I'm not familiar with the Cyrix units. I'll read up on the links.

Larry Davick



The site Applie posted was is some language I can not read and did not bother to run through an online translator. If you go download the .pdf files on the units they are in English.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230743 is a reply to message #230717] Fri, 22 November 2013 02:35 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
there is always this

link
http://thedovetailjoint.squarespace.com/storage/GMC%20Battery%20presentation%20v3%20reduced.pdf

gene



On Thu, Nov 21, 2013 at 6:32 PM, Larry Davick <ljdavick@comcast.net> wrote:

> Thinking about my Sister-in-law's off-grid home made me think of the GMC
> (it often does). Many on the list have multiple 12 volt battery banks that
> are connected in parallel. I know that paralleling batteries can be bad,
> so I began to wonder if any intelligent soul has developed a "combiner /
> isolator" that would allow all banks to act isolated 12 volt batteries -
> charge and draw power as needed, combining all banks when needed for big
> power draws. I can't be the first to think of this, but Google hides this
> secret from me.
>
> It's analogous to computer hard drives in a storage array. Back-when, to
> make a terabyte array you would combine similar disks (same manufacturer,
> model, etc.), into a raid array to gain the capacity needed (excepting for
> the loss of the checksum data.) Drobo set the low-cost RAID world on it's
> ear by making a device that would take ANY SATA drive and allow you to toss
> it in the mix. As the array fills up you replace the smallest disk. I
> simplify, but you get the idea.
>
> It seems to me this kind of device would be very practical when you want
> to add a bit more capacity without replacing the entire battery bank. It
> would also allow for old weak batteries to be used much longer as they
> won't draw down the other banks. Imagine the Ragusa trays filled with
> batteries. Aside from a 20,000 lb. coach it would be nice to boon-dock, or
> run a bigger inverter as needed.
>
> Any thoughts about living HUGE in a GMC? Am I making too much of the
> paralleled battery issue?
>
> Larry Davick
> Fremont, California
> A Mystery Machine
> '76 (ish) Palm Beach
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230745 is a reply to message #230742] Fri, 22 November 2013 02:50 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
I believe these Cyrix units are close to what I'm looking for.

You know the logic could be controlled by a chip, or a Rasberry Pi if the switches and sensors could be figured out.

I'd like the system to allow:
Separation of 12 volt battery banks
Multiple bank capacity (2, 4, 10?)
Intelligent solar/generator/grid battery charging (MPPT?)
Monitor the AC load and connect additional banks as needed
Cycle the load among each bank to even the wear
Kick off the generator when needed to charge the batteries
Kick off the generator to handle any excessive load.
Logic that is aware of each battery bank capacity, age, temperature - user enters date and model of the battery and WiFi connection allows a specification look up of the battery characteristics, or user entered metrics.
Automatic electrolyte monitoring (to understand boiling)
True sine wave inverter

You'd think being in the middle of Silicon Valley I could gather 3 neighbors in my garage and make this.

Larry Davick

P. S. It should cost no more than $200 and the user interface should be as simple as an iPhone or a Nest thermostat.
_______________________________________________
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
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230746 is a reply to message #230743] Fri, 22 November 2013 03:04 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
I'd recommend this to anyone who might dry camp. Jerry's presentation made a big impression on me. There is a lot of information packs in those slides.

Add solar, like Dan & Teri and your free from the Troll for most needs.
<http://thedovetailjoint.squarespace.com/storage/GMC%20Battery%20presentation%20v3%20reduced.pdf>

Larry Davick
_______________________________________________
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
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230755 is a reply to message #230724] Fri, 22 November 2013 06:32 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Larry,

I think if you visit Yandina.com, you'll find that their combiners have a
lead, which we seldom use, which can cause the relay to close when it's
activated. In other words, the combiner can be "manually" controlled. For
most uses, that should satisfy your requirement. If you want to automate
that "manual" activation, you'll have to design a load sensing circuit to
provide the activation -- but the relay can still perform the load
switching.

Call Yandina and talk to Andina Marie Foster, inventor of the combiner; she
may have already done something like that.

Ken H.


On Fri, Nov 22, 2013 at 12:18 AM, Larry Davick <ljdavick@comcast.net> wrote:

> I understand the combiner to charge the batteries, but what if you want to
> draw a big load where all banks should be connected as one big battery?
> Splitting the batteries up by function might work, but what if you want to
> run the microwave where all batteries would make sense?
>
> Larry Davick
>
> > On Nov 21, 2013, at 6:53 PM, Bill Wevers <gmc1975@att.net> wrote:
> >
> >
> >
> > Larry,
> > Read here:
> > http://www.yandina.com/combInfo.htm#Q12
> >
> > It says that you add a combiner for each bank.
> > When you figure it out, please explain it to me. :lol:
> >
> > -Bill
> > _______________________________________________
> > 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
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist



Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230756 is a reply to message #230736] Fri, 22 November 2013 06:49 Go to previous messageGo to next message
Bob de Kruyff   United States
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
Senior Member
""Appie,

I think the combiner only handles the charging side, not the load (or draw) side.

I want all the power when I need it but none of the problems of parallel batteries.

Larry Davick""

Larry, if your batteries are relatively matched (same size and age), I personally wouldn't worry about having them wired in parallel. I run two sets of 6V banks hard wired together. When the ignition is on, a relay also connects those to the chassis battery so that they all charge together.


Bob de Kruyff
78 Eleganza
Chandler, AZ
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230763 is a reply to message #230756] Fri, 22 November 2013 08:35 Go to previous messageGo to next message
appie is currently offline  appie   Denmark
Messages: 902
Registered: April 2013
Location: denmark
Karma: 2
Senior Member
if yoy read the cyrix ( victron) pdf you will sea that it seperates the batteries when they are full to avoid cycling and that they have a lead to Boost.

I think the Victron products are real cool and with the right combination the can everything wished for and do it well

designed in the Netherlands


Appie eleganza 76 "Olga" now sadly sold 6 wheel discbrake Quadrabags Springfield stage 2 462 olds Manny tranny ( pictures at http://www.gmcmhphotos.com/photos/g6489-olga.html Fulltiming in Europe july 2014 til july 2016 Denmark
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230767 is a reply to message #230763] Fri, 22 November 2013 08:46 Go to previous messageGo to next message
Bob de Kruyff   United States
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
Senior Member
""designed in the Netherlands ""

Well, no wonder !


Bob de Kruyff
78 Eleganza
Chandler, AZ
Re: [GMCnet] How to conect two 12 volt battery banks DROBO for batteries? [message #230771 is a reply to message #230732] Fri, 22 November 2013 09:49 Go to previous messageGo to previous message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
appie wrote on Fri, 22 November 2013 01:36

that is what this combiner does, it also has a booster build in

http://www.victronenergy.com/battery-isolators-and-combiners/cyrix-120a-225a-425a/

These devices look very interesting.
It would appear that they are more complex than a Yandina or other charge voltage only system combiner.
If I ever get another major house system build to quote, I will look these up and get some prices. Right now, that does not too likely.

They do have the small short coming that they will try to disconnect based on one of the batteries terminal voltage during charging. The assumption is that this is an indicator that the bank is fully charged. That is an unfortunate over simplification. The only ways I know of to know the state of a flooded cell is to measure the density of the electrolyte or do a time integration of the charge/discharge cycles and include a calculation of the efficiency (LA's do turn some of the charge current into heat). This is exactly what the Bogart and Xantrex charge monitors do.

The real good one I had to clean up some years ago was an extended cruiser that wanted more house bank capacity, so, he added (had someone) another 8D to the mix and the system controller that was part of his Xantrex inverter/charger kept telling him he now had less capacity. The funny part is that he did - until I rearranged the cable connections and recalibrated the system controller. He still could not get the full capacity of the (now 3ea) 8Ds because of the age difference of the batteries.

Even though it is DC, it can still be more complex that your high school science lab experiment.

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Previous Topic: [GMCnet] Drafting Guys Over 60 WAAAAY off topic!
Next Topic: [GMCnet] What's best /What to avoid: New water supply
Goto Forum:
  


Current Time: Sun Nov 17 03:55:35 CST 2024

Total time taken to generate the page: 0.01372 seconds