Rewiring boat, a couple of questions

[Billua]

Hello gents,

Been relatively warm in Vegas and I am way ahead of the power curve for seasonal maintenance.

I have bought two new AGM batteries.

I am installing a Blue Sea On/OFF/Combine Switch with the Bluse Sea ACR with SI.

The questions/issues that I have as I have been reading all of the threads and advice are:

I have already bought a dual bank Guest onboard charger before I had all this thought out.

So, IF I install the ACR with the normal configuration of Batt A + on one side and Bat B + on the other and hook up the dual battery charger normally, I assume the battery charger will close the ACR and the batteries will parallel instantly when onshore.

If this is true, does it really matter as there is only a max of 10 (2x5) amps going to the batteries but, they do try to equalize...

Or, should I somehow prevent the ACR from closing onshore by maybe installing a SPST switch on the ground wire of the ACR ?

Or, how about putting both sets of leads from the onboard charger to my house battery only being as how the batteries are both brand new and identical and letting the ACR work as designed?

Or, am I over thinking this?

Also, I have a roll of 4-0 welding cable. Will this have enough capacity for the ACR ?

Also, as far as the start isolation wire, is it best to go from the starter solenoid or key?

Last question. The boat was wired with all grounds on one battery along with the -cable from the second battery. Is this OK, or should I use a grounding terminal block to move the grounds off of a particular battery?



Thanks

[Billua]

Anyone?

[chpthril]

Here are some thoughts below in RED Im not sure if you are installing the 2 AGMs as the house bank or 2 new ones for both the house and starting banks.

Hello gents,

Been relatively warm in Vegas and I am way ahead of the power curve for seasonal maintenance.

I have bought two new AGM batteries. Are these both for the "House bank, or will one be starting and one house?

I am installing a Blue Sea On/OFF/Combine Switch with the Bluse Sea ACR with SI.

The questions/issues that I have as I have been reading all of the threads and advice are:

I have already bought a dual bank Guest onboard charger before I had all this thought out. Just confirm your Guest charger can be configured for both flooded and AGM batteries

So, IF I install the ACR with the normal configuration of Batt A + on one side and Bat B + on the other and hook up the dual battery charger normally, I assume the battery charger will close the ACR and the batteries will parallel instantly when onshore.

If this is true, does it really matter as there is only a max of 10 (2x5) amps going to the batteries but, they do try to equalize... If you are using two different battery types, I would disable the ACR during shore-power charging.

Or, should I somehow prevent the ACR from closing onshore by maybe installing a SPST switch on the ground wire of the ACR ? A simple ON/OFF switch in the ground circuit will do this. You just have to get in the habit of closing it once the shore charge is done.

Or, how about putting both sets of leads from the onboard charger to my house battery only being as how the batteries are both brand new and identical and letting the ACR work as designed? What size batteries? 5A may not be enough to replenish a depleted house battery, depending on its Ah rating. A depleted battery needs a little kick in the arse charge as the first stage to get it going.

Or, am I over thinking this?

Also, I have a roll of 4-0 welding cable. Will this have enough capacity for the ACR ? The ACR itself isn't whats drawing the current, its the batteries, and the alternator is the source. 4/0 is some honking huge cable! So basically, the main load going through the ACR will be the alternator output. So you just need to account for the Alternators max output and the distance of the runs. In most installs, 4ga is all thats needed.

Also, as far as the start isolation wire, is it best to go from the starter solenoid or key? You just need to make sure it only has B+ when in start and not when the engine is running. This pop with some Centurions. The start terminal off the switch ended up getting some back-feed when the engine actually was running, the ACR's stayed open.

Last question. The boat was wired with all grounds on one battery along with the -cable from the second battery. Is this OK, or should I use a grounding terminal block to move the grounds off of a particular battery?

Even though both banks share a common engine ground, its always habit to just terminal my amps to the house battery. After that, its best to even out the ground rings so neither post is over loaded with cables. This makes it tough to get the nut tight. Even then, if there are too many, then get a remote post to share some. Also, toss the wing nuts and use ny-lock nuts on the batteries.

Thanks

[Billua]

CHPTHRIL, thanks!

The batteries are brand new sears platinum, PM 2 880 Cold Cranking Amps –
135 Minutes of reserve capacity.

I plan to use one for the house battery and one for starting. I take my batteries out during the winter, so will trade them around each season.

I checked my boat and it will be no problem to wire off the starter for the SI.

I do think the suggestion for a On/Off switch on the ground circuit is the way to go. I may use a toggle switch type with the red aircraft guard on it so that it is obvious if the switch is open or closed and will stay closed bouncing around on the lago.



I am concerned that my charger may not be large enough and will have to see what happens.

Thanks much!

[chpthril]

With a quality smart charger, there would not be a need to pull the batteries if you have power where the boat is stored.

[Billua]

With a quality smart charger, there would not be a need to pull the batteries if you have power where the boat is stored.

Good point! I was worry about the occasional freeze though..

Also, is a grounding block rated at 150 amps capacity normally enough? I have a pretty standard factory installed stereo in the boat and would like to move the grounds off of the battery post to clean things up.

Thanks

[chpthril]

As long as the batteries are kept charged, they will not freeze, so you should be good with the on-board charger.

That GND block should be fine for sharing some of the ground cables.

[Billua]

Gotcha! Thanks for all.