View Full Version : Adding a 2nd Battery & Isolator???

05-19-2009, 10:27 AM
I have a 2005 Moomba Mobius LSV. I want to hook up a second battery with an Isolator.

Has anyone attemped this?

Is there an enticer wire from the alternator to the battery, if not do I need to wire one in and where do I connect it to the alternator?

My Biggest concern is the big red cable coming from/going to the starter (where it gets hooked up to) and what I need to do regarding hooking it up to the alternator. Running a seperate wire to it etc?

Pros and cons of such set-up?

05-19-2009, 10:57 AM
Vern, welcome to the forum!

There are no cons to a dual batt setup other than the initial cost.

When adding a another batt you don't mess with the existing factory wiring at all other than to possibly reroute under the forward storage compartment.

I would recommend the Blue Sea 7650 Add A Battery (http://bluesea.com/category/1/productline/overview/329)setup, imo there's nothing better.

IMO Costco Marine Deep Cycle Batteries are good with a good price for most people.

05-19-2009, 11:05 AM
I installed the Surepower combiner over the winter and it works perfectly. No switches to worry about....it does it all in one.

Heres the link...


Email them and they will help you with any questions.

05-20-2009, 01:46 PM
I agree with the sure power battery separator, they produce aome great stuff and have been around since the 50's, here is some info on them as well http://www.ase-supply.com/Sure_Power_Isolators_kits_s/20.htm

05-22-2009, 09:14 AM
Thank you all for your input.


05-22-2009, 02:31 PM
I just finished doing this to my 2001 Outback DD this week. I used the Blue Sea Add-a-battery kits. It works awesome. The installation instructions show a wire from the alternator to the battery, but you won't need it on our type of boats. It was kind of a pain to do, and the additional wire and connectors cost more than the switch. Mine was a pain because I didn't want to lose any more storage space with the second battery (or the first for that matter) so I got creative. I cut a large hole in the floor between the driver seat and the obeservers seat (kind of where the ski locker is on some boats) and dug out all of the foam and mounted both batteries below the floor. I wired them up to the switch and isloator behind the observers seat, and fabricated a new floor piece and carpet it so it blends in with the original floor. It does make a slightly raised area in the floor, but well worth having the batteries out of the way, and getting the weight of them right over the keel. The one additional thinkg I did, since the batteries are more difficult to get to, is I hard wired leads for a battery charger/maintainer to my deep cycle stereo battery so I can plug it in and charge it without having to open up the floor. As for the starting battery, the factory alternator does a fine job of keeping that charged. The great thing about this setup with the isloator, is that I can be anchored out playing the stereo, and I am only draining my deep cycle battery, not my starting battery. However, when the boat is running, they are combined and I am charging both batteries.

06-01-2009, 10:52 PM
Vern or Ncsumoomba,

i am looking to move my batterties for extra storage, got any pics of the main wire extension from the engine compartment??

06-03-2009, 01:03 PM
I didn't have to extend my main wire since mine is a direct drive, it was plenty long. I just had to add new ones to connect all the stuff together. I have been meaning to post some pics, but haven't gotten to it yet.