Adding a House Battery to Bayliner VR5

[Skyharbor12209]

I want to add a second battery, a "house" battery to my 2017 Bayliner VR5 with a 115 HP Mercury 4 stroke EFI engine. Right now, I have one battery, the one that came with the boat. I want to add a second battery and have seen a few diagrams about how to do this but no mention about the size of the connecting cables. I don't see anything listed on the POS and NEG cables coming from the engine, but not sure what size it is.

What size connecting battery cables should I use?

Also, right now the AM/FM radio, Lowrance unit, lights, bilge and VHF radio all must be connected to this one starting battery. When I add the second battery for "house" how do I split off the wires for the ancillary devices so that it is powered by the house battery? I have little knowledge of experience with DC current, so any help would be very much appreciated.

And finally, on the NEG cables that I have now, one is the larger black cable, but there is also a small gauge black wire. Does this wire go to "engine ground"? The diagrams to add a second battery show the need to connect cables to engine block. Was hoping that this smaller gauge black wire does go to ground already and I don't have to run a separate line. Thanks!!

 

[alldodge]

The size cables/wires to use depends on what will be connected to it. Using just what is listed so far, I would use 10 gauge wire, Run a Red and Black from the new battery to a new fuse block. Then connect the VHF, radio and other to it.

Your current black wire probably goes up to the current fuse block but you need to follow the wire to verify

Will also need to connect the house to the motors charging system with something like a "Add a Battery" using a ACR or charge it at home by plugging into a charger

 

[Skyharbor12209]

Thanks! It is confusing because I see mention of 2, 4 and 6AWG for the jumpers, but you think 10AWG is okay? Appreciate your help!!

 

[alldodge]

Actually with what your listing 12AWG would be good enough, but 10 allows for expansion later

 

[Skyharbor12209]

Thanks for your reply and help!

 

[dingbat]

Thanks! It is confusing because I see mention of 2, 4 and 6AWG for the jumpers, but you think 10AWG is okay? Appreciate your help!!

I think we’re talking two different things.

The only 2,4 and 6 awg wires are battery cables. The term “jumpers” would lead to suggest the cables running from ACR to each battery and or the battery cables proper.

If that is the case, duplicate cable size with existing battery.

The cables connecting the ACR to each battery is determined by length and load.

I used 6 AWG on mine with a 35A load.

This will help select the proper wire size

http://assets.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg

 

[Skyharbor12209]

Thanks. Where are you getting the 35 amp load figure from? I am not sure what mine is, where do I find that?

 

[klaszek]

I am looking to do the same with my 2016 vr5. Any chance you could share some pictures of your setup/ the finished product?

 

[jbcurt00]

It's been 1.5yrs since skyharbor even logged onto iboats
Not likely to get or reply to your message, Hence the 90day rule

Closed