Rewiring a Uniflite

[BC4Lyphe]

Edit: Currently trying to figure out how to put pictures on here.

Hi I just joined the forum and have been reading up on how to set up the batteries. I noticed a lot of guys saying the old school method is antiquated and to use a G31 for starting and shift the rest to house power. It's been a long day and my brain stopped working but heres what Ive got.

Twin Volvo 60Bs, it had a generator in the laz the PO pulled but the wiring and fuel is still back there, along with an 8D, waiting for a new genset to be dropped in. Port 8D was port start and fused to the 12v panel. Stb 8D was just for starting the stb engine. From what I can tell the laz 8D was used for house power and starting the generator. There was also another pair of 2/0 wires going to the laz from the engine room that werent hooked up to anything.

I bought the boat and it was a mess. So I moved the battery boxes to the sides to free up space around the engines. I'm currently tracing, eliminating, updating the engine room wiring. The only On/Off switcg was to tie the port and stb batteries together, which was wired to a starter relay for some reason (still need to trace the trigger wire). It has a Guest 2403-R isolator as well.

It's got three new 8Ds. A new P12 three bank charger. Three new 1,2 Both, Off switches. It's also got another 8D that isnt being used. I was thinking about adding it into a house bank.

I'm wondering what the best way to set it up would be. I really need to be able to start either engine with any battery. Generator can be a stand alone system with 110v trickle charger if need be or switched off one of the engine room batteries, not really thinking about that as of yet.

 

[SteveK]

Welcome
with what you have to work with I would hook 2 batteries together for 12 volt house batteries and one for start only for both engines. one engine charges the start battery, the other charges the house bank. You have enough switches to offer a wiring configuration to be able to use multiple setups. I would keep the start battery isolated from the house though without a switch that may be left on 'all' by accident.
That may change if you plan on putting a genie back in. But one of those will start 2 engines and a genie leaving two for the house, especially if you start the charging engine first.

 

[Pete Meisinger]

I would not connect the used 8D to your new batteries. Batteries tied together should be about the same age, power and condition. Just keep it for an emergency spare or use it for your windless.

pete

 

[O C Diver]

You don't mention what chemistry the 8Ds are, open lead acid or AGM? If you plan to use some as a house bank, probably should change them for a deep cycle type.

As previously mentioned, I would start both off the same battery and use the 2nd engine alternator to charge the house bank. Pretty simple to put a battery switch between the two banks to combine them in case of a depleted start battery.

I applaud your effort to clean up the wiring and remove the orphan wires (those no longer used).

Ted

 

[BC4Lyphe]

Trying some photos

 

[BC4Lyphe]

As you can see it was quite a mess. I spent very little time on the boat because it was 19 degrees and blowing a gale. I will get photos of the progress tomorrow. Right now Battery 1 (port) and Battery 2 (stb) are Car Quest 908DFT and the House battery is an Interstate 8D-XHD. I'm not sure if they're AGM as there are water filling ports in them. All three are new. I've got the Windlass switched and fused to Battery 2. The house battery can be tied to either 1 or 2. All three are fed with the isolator as well as the P12 battery charger. As people have said I plan on using Battery 2 for starting both engines and tying Battery 1 and House battery together the majority of the time using three Blue Sea 9001e switches and a Blue Sea 6006 giving power to the windlass. If I have the three bank charger and three bank, dual alternator feeding the three separate batteries will there be an issue when Battery 1 and House are tied together as a "single bank"?

 

[C lectric]

If the batts. have filling ports they are NOT AGM or GEL. They are flooded, old style wet cell batteries.

Should not be an issue. You could remove one of the charger output leads since the two house batts. will get the charge from the remaining lead. Nothing wrong with two leads to the house battery either, just redundant.

I am going to suggest, strongly, that you look up :

Nigel Calder Boatowners Mechanical and Electrical Manual and get one.

He is on the fourth edition now at ~ $50 - $60 new.
Or go to used and get an older book. The older ones may not have much on the LiFePO4 and all the new electronics BUT the battery, switching and basic info will all be there. Study the book,. He is truly an expert on what you are dealing with.

 

[O C Diver]

Make an overall plan before you start.
You have a lot of work ahead of you. If replacing the breaker panel(s), allow for additional circuits.

Ted

 

[BC4Lyphe]

Quick update to an old thread. Its been working ok for awhile, just wanted to be sure I wasnt overlooking something.

From port to stb-
Anchor windlass disconnect
"House" on common with #1 to port battery bus, #2 to stb battery bus
"Port" starter on common with #1 to port battery bus, #2 to stb battery bus
"Stb" starter on common with #1 to port battery bus, #2 to stb battery bus

Theres also a Neg bus below. Its kinda of cramped so I may add another just in parallel to get a few smaller lugs off the main one.

I have a P12 40 amp battery charger and the Guest battery isolator which are both 3 bank. Is there anything I'm forgetting? I was planning on adding another 8D in parallel to the house battery. All three batteries are 8D

 

[FF]

Any battery that can be switched to OFF should use rotary switches with field disconnect terminals.

Should the batts be switched off with the engine charging , cutting the field will save the alt diodes.

This style rotary is cheap insurance if you do not carry extra alt diodes.

The switches are break before break , the alt field is cut before the battery is cut off.

 

[Pete Meisinger]

Your old wiring looks like a plate of spaghetti. (Mine does also) I wish I could afford to have it totally redone. (I can't)

pete