New battery bank wiring diagram advice.

[Hoohaa]

Hi.
I was hoping that smarter people than me could have a look at my design and let me know whats right and whats not.
Particularly not shore if I have it fused correctly?

The diagram shows my existing setup, Solar/wind. I am replacing my 12v house bank with 690AH's worth of golf batteries in series and parallel and installing a Blue Seas Add A Bat. The battery bank is split into two locations.
Any help will be appreciated.
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[sailah]

This is the Maine Sail schematic I followed with parallel battery switch and Blue Seas ACR. Only difference is my Blue Seas parallel switch takes place of the 3 on his schematic. Works great if you follow all his recommendations.

https://marinehowto.com/automatic-charging-relays/

[Quebramar]

I had read that one should avoid connecting the main + and - to the same battery (set) because load will draw from it first and therefore create an imbalance between the 2 sets. You would best avoid by moving the main + to the other bank (since the - is connected to the shunt).

[smac999]

^. It’s hard if the bank is not in the same spot. You end up with a long main battery run. More cons then pros there.

I’d be worried with the 125a stating fuse. That Seems small.


Be careful with the switch at the house bank. Turning it off will feed power direct from solar to the loads. It should never really be turned off.

[Stu Jackson]

Originally Posted by Hoohaa

Hi.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
and installing a Blue Seas Add A Bat.

>>>>>>>>>>>>>>>>>>>>>>>>

Before you do this, you may be interested in these observations:


AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
https://forums.sailboatowners.com/in...teries.133773/

[Hoohaa]

Originally Posted by sailah

This is the Maine Sail schematic I followed with parallel battery switch and Blue Seas ACR. Only difference is my Blue Seas parallel switch takes place of the 3 on his schematic. Works great if you follow all his recommendations.

https://marinehowto.com/automatic-charging-relays/

Thanks. You helped me out before with this and I have printed it out and have been using it as a reference from the start.
I'm still using it.

[Hoohaa]

Originally Posted by Quebramar

I had read that one should avoid connecting the main + and - to the same battery (set) because load will draw from it first and therefore create an imbalance between the 2 sets. You would best avoid by moving the main + to the other bank (since the - is connected to the shunt).

If you're referring to taking the + & - feeds from opposite ends of the bank. So as not to make one battery do most of the work.
That's the way I have tried to wire it, it's just a bit hard to see with the bank being partially split in the diagram.
Let me know if I read your comments correctly.
Thanks

[Hoohaa]

Originally Posted by smac999

^.

It’s hard if the bank is not in the same spot. You end up with a long main battery run. More cons then pros there.

Unfortunately I don't have a choice here.

I’d be worried with the 125a stating fuse. That Seems small.

I sized this for the 2GA wire that it's protecting, my thinking process. If I went too high then the fuse would not blow and the wire would burn? I sized it 125% above the wire amp rating. This is one of the big questions I was hoping to get an answer on. What do you think?


Be careful with the switch at the house bank. Turning it off will feed power direct from solar to the loads. It should never really be turned off.

They are there just to isolate the batteries if I need to work on something and also to allow me to manually select a bank if one fails. Will normally never be used.

jj

[Hoohaa]

Originally Posted by Stu Jackson

Before you do this, you may be interested in these observations:


AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
https://forums.sailboatowners.com/in...teries.133773/

Thanks. I am using led acid and have solar and wind so thay should get a full charge when I'm not using the boat.

[Stu Jackson]

Originally Posted by Hoohaa

>>>>>>>>>>>>>>>>>>

I sized this for the 2GA wire that it's protecting, my thinking process. If I went too high then the fuse would not blow and the wire would burn? I sized it 125% above the wire amp rating. This is one of the big questions I was hoping to get an answer on. What do you think?>>>>>>>>>>>>>>>>>

It's not what we think, it's what the tables require:


Wire Sizing Tables www.bluesea.com also has good material on this and fusing, but it's a PDF download and doesn't link. Here's the link to the page, scroll down for the PDF download of the Fuse & Wire Sizing Tables: https://www.bluesea.com/support/reference

[Hoohaa]

Originally Posted by Stu Jackson

It's not what we think, it's what the tables require:


Wire Sizing Tables www.bluesea.com also has good material on this and fusing, but it's a PDF download and doesn't link. Here's the link to the page, scroll down for the PDF download of the Fuse & Wire Sizing Tables: https://www.bluesea.com/support/reference

I have used tha table and upped the fuse.
So here is the updated diagram.
I am hoping to use 2G wire for putting my battery bank in series and parallel and then using 0/0G wire to connect to the bus as shown on the diagram.
Does anyone see a problem with this?
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[CharlieJ]

Since you have to split the bank by neccesity, I strongly recommend that you ensure that the cabling is all the same length to ensure equal resistance for each current path otherwise one part of the bank will work harder than the other. Charging differences will also occur.

[Hoohaa]

Originally Posted by Quebramar

I had read that one should avoid connecting the main + and - to the same battery (set) because load will draw from it first and therefore create an imbalance between the 2 sets. You would best avoid by moving the main + to the other bank (since the - is connected to the shunt).

I see the mistake I made (I saw it this morning) Q.
This is the updated drawing with this problem fixed.
CharlieJ. I will try and have the wires equal length but this is going to be difficult. The only leads I can really equalise are the long Earth and long positive leads. It's a bit of a catch 22. The parallel leads are not possible to get equal.
Drawing number 6

[Hoohaa]

Here's an update. It's a quick install of part of the bank and we also replaced the start battery.
I need to go back and expand my battery box and devise a new system for clamping them down.
I did enjoy pulling out some of the obsolete cable. Allot more to come.
They fit.

[Quebramar]

Great enhancements. Are you able to isolate the bank from the engine room, heat is no friend of batteries!