Four 6V vs two 12 V house batteries

[NavyVet1975]

Any opinions on the advantages or disadvantages of four 6V vs two 12 V house batteries?

[Bob Denman]

I've heard it,said that you usually end up with more amp-hours in your pocket; with the 6 volt juice boxes.

[ducksface]

As a group we've pretty well disproved the 6v is better myth.
Size for sizen, weight for weight, lead for lead, there is no advantage to 6v cells.
Except
It allows you to put two 6v batteries into two smaller spaces where a single 12v of equal usability won't fit.

No other advantage outside of a laboratory. Dont chase half amps just to lose it through cable connections.
The myth dies hard.

[DavidEM]

Originally Posted by ducksface

As a group we've pretty well disproved the 6v is better myth.
Size for sizen, weight for weight, lead for lead, there is no advantage to 6v cells.
Except
It allows you put two 6v batteries into two smaller spaces where a single 12v of equal usability won't fit.
None other advantage outside of a laboratory.
The myth dies hard.

I respectfully and strenuously disagree.

6V batteries, better known as golf cart batteries, were developed to deal with routine, deep cycle discharging and charging as required by, well a golf cart. But that profile also fits well with RV and boating use.

GC batteries have filler ports on top (many 12V deep cycle batteries do also), thicker plates (don't know about 12V batteries) and more room above and below the plates for electrolyte (AFAIK no 12V battery does this).

No 12V batteries have all of these critical characteristics required for deep cycle use. All GC and GC2 batteries do.

Which is better? The battery that meets all of these critical characteristics or the ones that don't?

David

[ducksface]

The identical battery as a 12v has the identical characteristics.
This cannot be debated no more than d battery can be compared to aa battery.
If given the same specs, they perform the same.
Bulk, material and cell count.

Wet cell parameters are what you used.
When you move to other technology the reasons you present as specific solely to 6v batteries(they are not) disappear.

[NavyVet1975]

After this last week of freezing weather in Texas, I am doing my research on replacing the house batteries, just in case I have to. I appreciate all y'alls input on this subject.

[Pete'sMH]

Originally Posted by NavyVet1975

After this last week of freezing weather in Texas, I am doing my research on replacing the house batteries, just in case I have to. I appreciate all y'alls input on this subject.

I did he same week in south Texas using my 1 year old 2 OE flooded 12V batteries and they did the job without a hiccup. I didn’t want to sleep with the generator running so my furnace ran on the batteries. It was only overnight but the batteries were still showing 12.4 volts in the morning and started the generator easily.

[Judge]

This is directly from a battery manufacturer as to the difference between similarly rated 12V and 6V deep cycle batteries for RV applications and why 6V has an advantage. Take it for what it’s worth.



Advantages and Disadvantages of using two 12 volt batteries connected in parallel or two 6 volt batteries connected in series:

It would appear that there is no significant difference in capacity and voltage between these two examples. But this really is not the case. The plates designed for the T-105 use the same active material and alloy of the group 27 deep cycle batteries but both the T-105 negative and positive plates are 60% thicker than those found in the deep cycle 27 group sizes. The significance of this is that these 6 Volt batteries should have a longer lifespan than the two deep cycle 27 group sizes, if properly cared for. While the capacities are similar (220 versus 225 Amp Hrs.), battery longevity favors the two 6 Volt batteries. Why? Because a major cause of deep cycle battery failure is the shedding of active material from the battery plates.

[Beau388]

Originally Posted by NavyVet1975

Any opinions on the advantages or disadvantages of four 6V vs two 12 V house batteries?

Not surprisingly, I agree with Duckface. It is the weight of the lead paste in the wire grids that determines battery's capacity. Thus the heavier the battery the more capacity. It doesn't mater is is a single cell producing 2.12 volts or a 24 cell battery producing 50.9 volts. There are GC-2 GC-8 and GC-12 battery sizes used in most common golf carts to produce the nominal 48 volts the cart's motors require. So whether you use 8 GC-2, 6 GC-8 or 4 GC-12 batteries the all work just the same. The only advantage is less cabling for 4 batteries as compared to 8 batteries. So are two 30 lb 6 volt batteries better than one 12 volt 60 lb battery is producing the same amp-h? NO! Is a starting battery good to be use as an house battery? No. Is a deep cycle battery just as good as starting battery to start the RV engine? NO.

There are three basic types of flooded lead-acid and AGM batteries: starting, marine/RV and deep cycle. Their only difference is the number of plates per cell and the thickness per plate. Thicker plates mean more recharge cycles but at at a very low current flow. Starting batteries have many thin plates per cell and can provide an extremely large current flow but for only a short time. Discharging them below 80% of the capacity will shorten their cycle life and can warp the plates. Marine/RV batteries are designed basically to run trolling motors that require a fairly large current for a long time. They tend to be more rugged than deep cycle and starting batteries. With a marine/RV batteries, the max amperage load should be limited to about 100% of the amp-h capacity. Where as a deep cycle should be limited to 50% of its amp-h capacity. This is not an absolute valve but the recommended value for max battery life.

[ducksface]

Has anyone (besides me)seen the battery of batteries at
Scotty's castle near Beatty/Death Valley?
Many to most of them are 100 years old.

I'm probably not memberberrying correctly, but I think they're 600lb 1.2 volt cells.
Maybe 200 of them.

[Bob Denman]

I guess it's a Die Hard...

[16ACE27]

Originally Posted by NavyVet1975

Any opinions on the advantages or disadvantages of four 6V vs two 12 V house batteries?

The premise of your question is incorrect:

The proper comparison is (4) 6 volt batteries Vs. (4) 12 volt batteries.

It should be obvious that 4 batteries always outperforms 2 batteries assuming all batteries have the same physical dimensions.

[Chance]

Originally Posted by Judge

This is directly from a battery manufacturer as to the difference between similarly rated 12V and 6V deep cycle batteries for RV applications and why 6V has an advantage. Take it for what it’s worth.



Advantages and Disadvantages of using two 12 volt batteries connected in parallel or two 6 volt batteries connected in series:

It would appear that there is no significant difference in capacity and voltage between these two examples. But this really is not the case. The plates designed for the T-105 use the same active material and alloy of the group 27 deep cycle batteries but both the T-105 negative and positive plates are 60% thicker than those found in the deep cycle 27 group sizes. The significance of this is that these 6 Volt batteries should have a longer lifespan than the two deep cycle 27 group sizes, if properly cared for. While the capacities are similar (220 versus 225 Amp Hrs.), battery longevity favors the two 6 Volt batteries. Why? Because a major cause of deep cycle battery failure is the shedding of active material from the battery plates.

I’m curious where this came from if it’s a battery manufacturer?

I found this quote copied over many times going over ten years in posts in various threads, but since it appears to be mentioning Trojan batteries, I went there and can’t find it. Doesn’t mean it’s not and I just can’t see it.

Trojan Q&A section doesn't address this, but interestingly enough recommends 24 or 48 Volts for systems using over 100 Watts steady. Makes me wonder since that’s an incredibly low bar to set at 8.5 Amps for 12 Volt systems, and practically no one follows that recommendation even when pulling well over 100 Amps.

Just curious if you saw the original source of that statement.

[Lt Keefer]

You might have well asked Republican or Democrat, Yankees or Red Sox. There is no right answer, only the answer you believe in, but if you research the interwebs you will find in the old days 6 volt golf cart batteries were way superior to 12 volt deep cycle batteries. The 6 volt golf cart battery was capable of many more charge/discharge cycles than a 12 volt deep cycle. Therefore lasted longer. Now a days they are both inferior to the modern technology and size choices of lithium ion batteries.

[Judge]

Originally Posted by Chance

I’m curious where this came from if it’s a battery manufacturer?

I found this quote copied over many times going over ten years in posts in various threads, but since it appears to be mentioning Trojan batteries, I went there and can’t find it. Doesn’t mean it’s not and I just can’t see it.

Trojan Q&A section doesn't address this, but interestingly enough recommends 24 or 48 Volts for systems using over 100 Watts steady. Makes me wonder since that’s an incredibly low bar to set at 8.5 Amps for 12 Volt systems, and practically no one follows that recommendation even when pulling well over 100 Amps.

Just curious if you saw the original source of that statement.

I’ll see if I can find which one. I copied it from a website years ago when i was doing reaerach on the topic.

But the statement is logical as the 6V batteries are similar in weight as a 12V but only generate half the voltage. It stands to reason as it means the voltage to material weight ratio is higher for the 6V and it in fact should last longer if properly maintained.

[IDguy]

Originally Posted by ducksface

As a group we've pretty well disproved the 6v is better myth.
Size for sizen, weight for weight, lead for lead, there is no advantage to 6v cells.
Except
It allows you to put two 6v batteries into two smaller spaces where a single 12v of equal usability won't fit.

No other advantage outside of a laboratory. Dont chase half amps just to lose it through cable connections.
The myth dies hard.

Not a myth for me. Get two nights heating w 6 v vs. one night w 12. They have nearly twice the amp hours.

[IDguy]

Originally Posted by ducksface

Has anyone (besides me)seen the battery of batteries at
Scotty's castle near Beatty/Death Valley?
Many to most of them are 100 years old.

I'm probably not memberberrying correctly, but I think they're 600lb 1.2 volt cells.
Maybe 200 of them.

Yes. Edison’s name is on them. I have pics somewhere.

[Bob Denman]

I hope you,can find and post them!

[IDguy]

Not to confuse things with data.

Keep in mind you double the 12v amp hours to compare...or look at two battery column.

[16ACE27]

Originally Posted by IDguy

Not a myth for me. Get two nights heating w 6 v vs. one night w 12. They have nearly twice the amp hours.

Yep, 6 volt batteries that are the same size as 12 volt have double the amp-hours................... at 6 volts.

So you need two of them in series to get 12 volts - now you have the same number of amp-hours.....................................at 12 volts. which is exactly the same as putting those two 12 volt batteries in parallel.

Amp-hours is a useless unit without the voltage associated with it. To really measure the "capacity" of a battery you have to state how much energy it stores in Watt-Hours.

A common deception in marketing 12 Volt Lithium battery packs/"solar chargers" is to state the Amp-Hours of the pack based on the single Lithium cell voltage (plus they use milliamp-hours to make the number much larger) of 3.6 volts instead of the implied 12 volts, so the number is 3 times as large.