House batteries

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rvrrat

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Not sure which way to go....the single 12v house battery does not last long enough dry camping. Would I be better off going with two 6v or two 12v batteries? Anyone have info or experience with this, would appreciate info....thanks.....
 

Tom

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Two golf-cart style 6V batteries connected in series to give you 12V will give you approximately the same capacity as two 12V group 27 deep cycle batteries connected in parallel. The golf cart batteries are made for daily deep cycling, so they would be my preference.
 

Lou Schneider

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Two six volt batteries are my preference.? A pair of 6 volt batteries has about the same capacity as a pair of 12 volt batteries, but the 6 volt version only has half as many individual cells - 3 for each 6 volt battery vs. 6 for each 12 volt.

Since the 6 volt version has half as many cells, each cell is twice as large as the equivilent 12 volt cell.? Larger is better for deep cycle use.  The 6 volt cells have larger components - thicker plates more electrolyte, etc.

The other big advantage to using a pair of 6 volt batteries are the way they are connected to get 12 volts.? If you trace the current path through a pair of series connected 6 volt batteries, there is one and only one way for electricity to flow through them.? This means all of the cells get equal amounts of charging current, and all contribute equally to the load when you're using power.

With a pair of 12 volt batteries connected in parallel, there are two paths the current can take - part of the current flows through one battery, part flows through the other.? ?This means unless the batteries are precisely matched, one will draw more charging current than the other.? ?Likewise, when you use power, one battery will contribute more power than the other.? This makes it harder to get full capacity out of both batteries.
 

John From Detroit

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Lou said:
The other big advantage to using a pair of 6 volt batteries are the way they are connected to get 12 volts.  If you trace the current path through a pair of series connected 6 volt batteries, there is one and only one way for electricity to flow through them.  This means all of the cells get equal amounts of charging current, and all contribute equally to the load when you're using power.

With a pair of 12 volt batteries connected in parallel, there are two paths the current can take - part of the current flows through one battery, part flows through the other.  This means unless the batteries are precisely matched, one will draw more charging current than the other.  Likewise, when you use power, one battery will contribute more power than the other.  This makes it harder to get full capacity out of both batteries.

There is another advantage.. With 2 six volt parrallel if you loose a cell... You loose 2 volts and can easily figure out which it is with a 10 dollar VOM

With 2 12volts in parrallel.. You loose a cell you may well loose both batteries cause one of them sees what amounts to a near short circuit and the other is suddenly being overcharged (Loose = shorted in this case)  This can cause a build up of gas near the battery, 2 parts hydrogen to one of oxygen (the perfect combustion ratio) and one spark later... Nice knowing you
 

Karl

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John,
For flooded cells, when a battery goes bad a cell typically will open up; not short out. Thus, if you lose one cell, your voltage will drop considerably as will the amount of current you can draw thru the two batteries in series. With batteries in parallel, loss of a cell in one of the batteries will typically just cause a reduction in overall capacity, but will retain the voltage at the level of the good battery. The best overall hookup is 4-6volt (or 4-12 volt) batteries in a series/parallel arrangement. That way you can simply remove one jumper to disconnect the offending string of batteries. Granted, you'll lose half your capacity, but not suffer a drop in voltage. I plan on adding a second bank of 6volt batteries in just such an arangement. Also, if you notice a significant drop in electrolyte level in one cell, you should check it with a hydrometer. That's the best way of checking its' health and will, in most cases, warn you of an impending failure. Battery explosions are quite rare and are almost always the result of neglect or improper jump-starting procedures. 
 

John From Detroit

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Tom said:
Assume you meant two 6 volt (batteries) in series, since we're talking 12 volts.

Yes I did, thanks for catching it

Question, how do you reply w/o quoting, or do you just hit quote and delete what it puts on your screen?
 

John From Detroit

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I recently found a site that has a compairsion of AGM v/s GEL cell batteries for use in assorted uses

This site caters primarlly to Ham Radio and Radio Controled model types (I'm WA8YXM)

http://www.westmountainradio.com/pdf/AGMvsGEL.pdf

Note: My motor home will have one of their RIGRunner 12 volte distribution panels installed so I can plug in radios, GPS, computer and such easily (and even unplug and transfer to the car, which will have a much smaller RIGrunner)  These products use the Anderson Power Pole connectors which are very nice and pass up to 40 amps.

They also have charging controllers, auto-switches, analyzers, and a host of other goodies for 12 distribution and control  Very nice line of products for folks using 12vdc to run stuff.  If anyone is interested.

Note: I have only one connection to this company... I'm a customer
 

fredethomas

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Work has it that Gell Cells have developed a real problem and might not be manufactured for very long.  Story is the gell is drying and cracking.  I expect the wrong charge voltage has something to do with it.  Must charge them slow.
 

Len and Jo

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Gee John...
The Rigrunner makes my 5 12v cigarette type outlets look very out of date.  Only thing I can say is that, other then 12v telephone charging we haven't used them.  You ham operators must have lots of stuff.  Over time I have found that we use 110v a/c while going down the road much more then 12vdc.  I think I put in to many 12vdc outllets when I build my 'B'.
 

John From Detroit

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fredethomas said:
Work has it that Gell Cells have developed a real problem and might not be manufactured for very long.  Story is the gell is drying and cracking.  I expect the wrong charge voltage has something to do with it.  Must charge them slow.

Yes, improper charging, over charging and too rapid charging will kill a gell cell faster than you can say "OH ____[deleted____"

This does not mean there is anything wrong with the battery though
 

John From Detroit

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Len and Jo said:
Gee John...
The Rigrunner makes my 5 12v cigarette type outlets look very out of date.  Only thing I can say is that, other then 12v telephone charging we haven't used them.  You ham operators must have lots of stuff.  Over time I have found that we use 110v a/c while going down the road much more then 12vdc.  I think I put in to many 12vdc outllets when I build my 'B'.

Well, when I get things straightened out I'll have a scanner which can run nicely on 12VDC (West Mountain Radio makes a power cable all ready for it) my Hand Held, another 2 meter rig, my GPS (Which has no 110 vac) and my laptop, that's the minimum, possiblity of other stuff showing up and/or dissappearing as the mood strikes,  Thus a 12 position in the MH and a 5 slot in the car (Which will have some stuff "Hard Wired"  The 5 slotter will be easily removable and can be hooked to a luggable battery if needed  (Jump kit)

I dropped an order for tools and additional accessories on West Mountain today

And we Hams do have a bit of stuff yes, and like to run it on DC when we can (Better filtering that way)
 

Karl

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Fred,

I'm wondering if the problem has something to do with people trying to equalize their gel cells; something that should never be done. That would surely cause problems. I worked with the Globe Battery Division of Johnson Controls who were one of the innovators of gel cells, and the only major problem they had was when overcharging, the gas valves would 'pop' and let the gas escape, rather than recombining as it should - kind of like leaving a plate of Jell-o stand out for a few weeks and ending up with a plate covered with a hardened, glue-like covering. Could that be what 'they' were refering to?
 
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