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 > Parallel 12volt, more capacity then AH rating? 2.7 x's more!

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BFL13

Victoria, BC

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Posted: 02/12/18 09:50am Link  |  Quote  |  Print  |  Notify Moderator

wnjj wrote:

valhalla360 wrote:

Tom_M wrote:

The video is simply a demonstration of Peukert's law. As the rate of discharge increases, the battery's available capacity decreases.


Yep, 6v or 12v shouldn't matter as long as they hold the same number of watt-hours at the same rated discharge and are both deep cycle designs (not labeled but actual design).


12 versus 6 matters if both are sped’d at the same discharge rate because a pair of 12’s will be drawing down at half the rate in the same system. The parallel 12’s will get the 10 percent bonus capacity that the series 6’s won’t. That never seems to come up in the “just add the amp hours” 12 versus 6 comparison threads.


That's because the typical 6 used in an RV is twice the AH rate of one 12, so a pair of 6s and a pair of 12s will be the same.


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pianotuna

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Posted: 02/12/18 10:18am Link  |  Quote  |  Print  |  Notify Moderator

Using 12 volt jars shines when an odd number of batteries fit the available space. That can give a genuine boost to the number of watt-hours.

If cheap large wattage inverters were not in use then six volt would almost always be the route to follow.

Each person must use what serves their camping style best.

For a power pole princess even a tiny utility battery would work.


Regards, Don
Full Time in a 28 foot Class C, 256 watts solar, 556 amp hours of AGM in two battery banks 12 volt batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

BurbMan

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Posted: 02/12/18 10:25am Link  |  Quote  |  Print  |  Notify Moderator

SoundGuy wrote:

I installed a 1000w PSW inverter in the front pass through storage compartment so we can still use a couple of 120 vac fans and make coffee & toast the same way we always do.


Good luck running a toaster with 2 12v batteries and an inverter. That inverter is going to shut down for low voltage before the first slice is even a little brown.

Fans, device charging, TV, etc, yes, but resistive appliances like a toaster? Nope.

I would put one of these in your gear:

[image]


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lawrosa

Horry County

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Posted: 02/12/18 10:40am Link  |  Quote  |  Print  |  Notify Moderator

BurbMan wrote:

SoundGuy wrote:

I installed a 1000w PSW inverter in the front pass through storage compartment so we can still use a couple of 120 vac fans and make coffee & toast the same way we always do.


Good luck running a toaster with 2 12v batteries and an inverter. That inverter is going to shut down for low voltage before the first slice is even a little brown.

Fans, device charging, TV, etc, yes, but resistive appliances like a toaster? Nope.

I would put one of these in your gear:

[image]



I guess you didnt see my video.. I could of made 500 pieces of toast...

https://www.youtube.com/watch?v=7p-oNT8YDIs


Mike L ... N.J.

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BFL13

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Posted: 02/12/18 10:43am Link  |  Quote  |  Print  |  Notify Moderator

BurbMan wrote:

SoundGuy wrote:

I installed a 1000w PSW inverter in the front pass through storage compartment so we can still use a couple of 120 vac fans and make coffee & toast the same way we always do.


Good luck running a toaster with 2 12v batteries and an inverter. That inverter is going to shut down for low voltage before the first slice is even a little brown.

Fans, device charging, TV, etc, yes, but resistive appliances like a toaster? Nope.

I would put one of these in your gear:

[image]


Well I have no trouble doing it. Of course you have to be very specific about just what the set-up is before saying it can or can't be done.

You do need the inverter to battery wires to be of low enough resistance (short and fat) and you need the two 12s to be of sufficient AH capacity at the time. It is easier if the two 12s are AGMs too.

wnjj

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Posted: 02/12/18 10:56am Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:

wnjj wrote:

12 versus 6 matters if both are sped’d at the same discharge rate because a pair of 12’s will be drawing down at half the rate in the same system. The parallel 12’s will get the 10 percent bonus capacity that the series 6’s won’t. That never seems to come up in the “just add the amp hours” 12 versus 6 comparison threads.


That's because the typical 6 used in an RV is twice the AH rate of one 12, so a pair of 6s and a pair of 12s will be the same.

My point was the pair of 12’s will be supplying half the current (each) at any given time so will actually have more capacity than a pair of 6’s if the 6’s only have 2x the A-h because of the de-rating with higher draw. Thus, a pair of 2x A-h 6’s will have 2x a single 12, but will have less than the pair of 12’s.

In this comparison I’m ignoring the other differences between 6v and 12v batteries. As others have pointed out, the typical ones available have further differences beyond just their A-h rating.

Now if 6v batteries’ ratings are at 2x the draw of the 12v ones, then they will be equal. I’m a EE but far from an expert on batteries.

pnichols

Santa Cruz Mountains

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Posted: 02/12/18 12:35pm Link  |  Quote  |  Print  |  Notify Moderator

SoundGuy wrote:

We normally camp on electric sites and based on that alone a simple G24 sitting on the tongue would serve the purpose. However, because we lose campsite power for one reason or another at least 2 or 3 times each season I installed a 1000w PSW inverter in the front pass through storage compartment so we can still use a couple of 120 vac fans and make coffee & toast the same way we always do.


I clipped the above portion out of your long post above to ask a question: When electric sites at a campground lose power - aren't campers who need to continue with 120V AC power and until the campground power is restored - allowed to use their generators if they have them?

I would think that would be accepted and expected by the campground managers and residents regardless of the temporary noise (and fumes). [emoticon]


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ependydad

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Posted: 02/12/18 01:00pm Link  |  Quote  |  Print  |  Notify Moderator

Go lithium and give Peukert the finger. [emoticon]


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SoundGuy

S Ontario

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Posted: 02/12/18 01:30pm Link  |  Quote  |  Print  |  Notify Moderator

SoundGuy wrote:

I installed a 1000w PSW inverter in the front pass through storage compartment so we can still use a couple of 120 vac fans and make coffee & toast the same way we always do.


BurbMan wrote:

Good luck running a toaster with 2 12v batteries and an inverter. That inverter is going to shut down for low voltage before the first slice is even a little brown.

Fans, device charging, TV, etc, yes, but resistive appliances like a toaster? Nope.


Baloney ... I've been doing this for several years now with just a single G27 supplying the inverter. Yes, if my G27 wasn't at full SOC then the draw down would often cause the inverter to alarm, though it never shut down ... with load support from the truck voltage doesn't come anywhere near close to shutting down the inverter. According to you though we've been eating imaginary toast. [emoticon]

lawrosa

Horry County

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Posted: 02/12/18 01:31pm Link  |  Quote  |  Print  |  Notify Moderator

ependydad wrote:

Go lithium and give Peukert the finger. [emoticon]


ha ha ha... LOLOLOL... Thats actually funny and made me laugh!!!![emoticon]

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