Connecting 2 batteries together

[swimmer_spe]

I have space for 2 batteries where I currently have one. The one I will be adding is identical, except it is about a year older. Am I right, I need to daisy chain them?

[swimmer_spe]

wa8yxm wrote:

Grit dog wrote:

Not sure of the myths…but for sure there are some guidelines.
Wondering what the addl concerns might be with 6V batteries though? You said there are concerns?
Aside from having to hook up in series or series-parallel I’m not aware of any “concerns.”

When you wire batteries in series you want Twins.. Same make, Model, Capacity, Age, as close to identical twins a possible.

I won't be wiring them in series as I need 12 volts and the batteries are both 12 volts.

[wa8yxm]

Grit dog wrote:

Not sure of the myths…but for sure there are some guidelines.
Wondering what the addl concerns might be with 6V batteries though? You said there are concerns?
Aside from having to hook up in series or series-parallel I’m not aware of any “concerns.”

When you wire batteries in series you want Twins.. Same make, Model, Capacity, Age, as close to identical twins a possible.

[swimmer_spe]

bob213 wrote:
Not sure about pairing batteries of different age but here's a great guide on how to do it correctly...12v side of life
12v

The 2 batteries are about a year difference in age as to when I bought them.

[swimmer_spe]

pianotuna wrote:
swimmer_spe

This is what is balanced and best for twin twelve volt batteries.



As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

correctly interconnecting multiple twelve volt batteries

Others may say it doesn't matter--but unless there is a compelling reason to not optimize charging and discharging why not do it the best possible way?

That picture was what I meant as daisy chain.

Looks like most places are recommending that setup, so I will follow that.

[valhalla360]

wa8yxm wrote:
There are a lot of myths about paralleling batteries.
For the most part the only thing you need to concern
The Connecting cables need to be large enough (Same as the cable that runs off to who knows where)

And the polarity.

Most everythign else the batteries will work out by themselves

In some very high current installs there is more (Load Balance) But you are into the hundreds of amp loads before that's a concern.

With GC-2's there are additional concerns but since you are not going that route. That is all folks.

^^^ This

If you were talking about a 1500amp-hr @12v bank feeding a 3000w inverter that will be used to run the air/con or some other heavy duty system, mucking about with load balancing becomes important.

For a couple of basic 12v batteries tied together to feed minor house loads, it's largely irrelevant. Even running something like the main tongue jack might be unbalanced but as soon as the load stops, the batteries will balance themselves.

[Bobbo]

Here is pianotuna's image. He is demonstrating exactly what I described above.

[pianotuna]

swimmer_spe

This is what is balanced and best for twin twelve volt batteries.



As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

correctly interconnecting multiple twelve volt batteries

Others may say it doesn't matter--but unless there is a compelling reason to not optimize charging and discharging why not do it the best possible way?

[Grit_dog]

wa8yxm wrote:
There are a lot of myths about paralleling batteries.
For the most part the only thing you need to concern
The Connecting cables need to be large enough (Same as the cable that runs off to who knows where)

And the polarity.

Most everythign else the batteries will work out by themselves

In some very high current installs there is more (Load Balance) But you are into the hundreds of amp loads before that's a concern.

With GC-2's there are additional concerns but since you are not going that route. That is all folks.

Not sure of the myths…but for sure there are some guidelines.
Wondering what the addl concerns might be with 6V batteries though? You said there are concerns?
Aside from having to hook up in series or series-parallel I’m not aware of any “concerns.”

[Grit_dog]

Bobbo wrote:
Hook the two POSITIVE terminals together. Hook the two NEGATIVE terminals together. For best results, hook the trailer's POSITIVE cable to the POSITIVE terminal of one of the batteries, and the trailer's NEGATIVE cable to the NEGATIVE terminal of the other battery.

THANK you. Lol

[Bobbo]

Hook the two POSITIVE terminals together. Hook the two NEGATIVE terminals together. For best results, hook the trailer's POSITIVE cable to the POSITIVE terminal of one of the batteries, and the trailer's NEGATIVE cable to the NEGATIVE terminal of the other battery.

[wa8yxm]

There are a lot of myths about paralleling batteries.
For the most part the only thing you need to concern
The Connecting cables need to be large enough (Same as the cable that runs off to who knows where)

And the polarity.

Most everythign else the batteries will work out by themselves

In some very high current installs there is more (Load Balance) But you are into the hundreds of amp loads before that's a concern.

With GC-2's there are additional concerns but since you are not going that route. That is all folks.

[bob213]

Not sure about pairing batteries of different age but here's a great guide on how to do it correctly...12v side of life
12v

[Grit_dog]

Dutch_12078 wrote:
No... Two 12-volt batteries must be connected in parallel to still supply 12 volts, but at twice the amp/hours. "Daisy chained" would supply 24 volts, possibly burning out most of your 12 volt devices.

Well in electrical terminology for daisy chain in residential IS parallel connections.
But potato pototo.
Yes parallel them. Not series.

[agesilaus]

Battery wiring