I lost my pics in my original post so here is a revived version (per Jim_R request) since I can't edit the original. Here is a link to the original post:
Add-A-Battery Project /w Pics _________________
Well I have been working on some boat projects and thought I should start putting some up on BABC. The first is the "Add a Battery" product from BlueSea Systems. It combines a 120A ACR w/ a Dual Circuit battery switch (Add a Battery - PN 7650).
First I picked up two Optima BlueTop D34Ms at Costco. Mostly because I could get them easily. I am using one for the boat and the other for the stereo. Most of my stereo listening is while we are motoring and I can plug in every night, so I didn't need a lot of AH reserve beyond one battery. I just wanted to isolate the boat battery and not have to think about how to set the switch for charging. So now it is just automatic.
Since I already had a dual battery setup with a BlueSea 1-2-Both switch the change out of the switch was easy and the hole pattern was identical.
To install the ACR I used 4ga Ancor Marine battery wire with 105C rated insulation. This gives me an ABYC rating of 136A in the engine compartment. I used a 100A Sea fuse at each battery Sea Fuse Block . Since they blow at ~ 130% of their rating that puts me within the rating of the wire. Also, since I have a 75A alternator I will running below 80% of the fuse rating per BlueSea System recommendations. Choosing Circuit Protection- BlueSea Systems Note they also recommend fusing the ground and the Start Interruption connections which I did. I made up a piece of Starboard to mount the ACR.
Here is one of the fuse blocks. The upper fuse block is for the stereo (post to come later).
Lastly, I needed an onboard battery charger. I choose the CTEK Multi US 7000 and connected it directly to the stereo battery since that will need to be charged most of the time. Once the stereo battery is up to voltage the ACR will kick on and top off the boat battery as well.
Well thats it. Enjoy.
-- Bob