Series/Parallel Wiring for 24Volt

[Pelagic]

I am having a trouble visualizing how I hook up these 6 x 12 volt AGM batteries each at 260AH to give me 780AH at 24 Volts

Can anyone help?

p.s. I think you can edit in Paint program... Thanks!

[cal40john]

Originally Posted by Pelagic

I am having a trouble visualizing how I hook up these 6 x 12 volt AGM batteries each at 260AH to give me 780AH at 24 Volts

Can anyone help?

p.s. I think you can edit in Paint program... Thanks!

The series connection does not increase amp-hour capacity, so two batteries is series is 260 AH, times 3 sets in parallel, 780.

Batteries - Series and Parallel Connections - The Alternative Energy Store



John

[GordMay]

You cannot - as it would require (12) 6V x 260 A/H Batteries to build a 24V x 780 A/H Bank [3 Paralleled sets of (4 each) Series Wired Batteries].

Series connections: Battery Voltage adds, Capacity remains the same.
Parallel connections: Battery Voltage remains the same, Capacity adds.

[Pelagic]

Thanks John,

I had your version #1 but I also came up with this version #2 which has more connections but I am not sure if there are pros and cons between the two ways.

My #2 has 9 connections (added resistance) versus #1 version with 7 with yours.

Is there a preferred way

[Pelagic]

Sorry guys, Electrics are one of my many weaknesses
Gord these are 12 volt batteries each see specs http://www.fullriver.com/products/admin/upfile/DC260-12.pdf

After Rick mentioned good results with testing some of the Fullriver products I have zeroed in on these to replace my existing house bank of 4 x 200AH Yuasa D batteries.

Would appreciate and advice if you think they are not appropriate for a liveaboard application

[GordMay]

Originally Posted by Pelagic

... Gord these are 12 volt batteries each see specs ...
... My #2 has 9 connections (added resistance) versus #1 version with 7 with John’s ...

OOPS, you did specify 12V - I just didn’t read it right (it’s “early” hours for me).
Actually, 7 cables = 14 terminations, which would be preferable to 18 (9 cables).

[Pelagic]

Thanks Gord, I thought i had screwed up....whew!

Does anyone have an opinion on the specs for those batteries as I am gong to confirm the order tomorrow

p.s. on the website if you click on headings like "Cycle Life" "Construction" etc it gives you more info

[GordMay]

Two good battery “quality” comparitors are:
Internal Resistance (actually impedance) in milliohms, where less is better.
Energy Density in watt-hours per pound or kilogram, where more is better.

Rick is qualified to add more detail to this topic.

[Pelagic]

My House Bank upgrade from the original 4 x Yuasa 200AH lead acid Truck batteries to the 6 x Fullriver 260AH deep cycle AGMs hit a snag as the much heavier AGMs put too much of a list on the original port side installation.

So I decided to buy 2 more and balance them Port and Stbd, giving me a total of 1040AH @ 24V

This takes me back to the wiring set up which will include a Master ON/OFF ( not installed before)

I did a drawing showing what the physical orientation of the batteries will need to be (Under Dinning Room and Galley). The Electrical Locker is actually only on the Port Side, but I scaled it up for clarity.

This is my first draft at how to make the connections……Any Comments?

[Joli]

We have a 24 v bank with 8 volt deep cells that has worked well. Scary working around all that amperage though.

[Whimsical]

With the batt switch in the center the positive is nicely balanced, even length run to either bank. The negatives could be bought back to a stud in the middle which would balance them as well.

Man that is one serious batt bank

Mike

[Pelagic]

Thanks Mike,

I had not thought about the need to balance the negative side.

Excuse my ignorance, but is that as important as well?


Is this what you had in mind?

Nick

[Whimsical]

Yes thats it.

I am not sure how important it is, have just seen it mentioned a number of times.
Some even suggest to take the positive from one end of a bank and the negative from the other end.

Mike

[Rodz]

Originally Posted by GordMay

Two good battery “quality” comparitors are:
Internal Resistance (actually impedance) in milliohms, .....

Gord ... are you sure that dc circuit has impedance? Impedance is the total value of resistance, capacitance and reactance .... Capacitance and reactance values depend on circuit frequency ... for dc f=0Hz. In this case both parameters would be zero. Correct me if I am wrong.

Pelagic - One word of advice on wiring - if you decide to wire as shown you have to remember that the cables size + & - between switch/(negative post) and HD studs should be calculated to carry maximum load current and also checked for possible short circuit current.

Cheers,

Chris

[Pelagic]

Thanks Chris I have calculated load with scenario of everything on at same time Windlass/BowThruster/3000w Invertor at Max/ Autopilot and all DC Consumables and sized cables per guidelines

I just discovered that BEP has come out with a Double Pole Battery Switch SKU: 720-DP 720-DP Double pole battery switch It has the same dimensions and features as the 720 battery switch

The 720-DP also meets the needs of vessels being built to survey requirements where positive and negative supplies must be isolated at the same time

720-DP Specifications

• [Continuous Rating: 400 Amps DC
• Intermittent Rating: 525 Amps DC
• [Cranking Rating: 1500 Amps DC
• Voltage Rating: 48 Volts DC
• Operation: On/Off two poles
• Termination Stud Size: 4 x 12mm (1/2")

So that will allow me to group both Pos and Neg Leads between the 2 sets of batteries before going to Distribution studs beside the 2 Chargers


I will also install prior to that between Batteries and Master Switch a Contour HD ANL Fuse Holder
SKU: 704-ANL Fuse Holder Heavy Duty Allows fusing of heavy duty accessories between 80A-500A.


Fuse will be rated at 250A


This BEP stuff looks pretty good…….Nick