Help, hooking up a second battery

duncans 05-13-2004, 9:09 AM

Hey Y'all,
I put tower speakers on my boat but the battery appears not to have enough power to run both the boat and stereo at the same time. I was told I need to hook up a second battery. Is this true? anyone done this? Any advice? What do I need to get?
I talked to my local schucks auto store and they just looked at me with a blank face and were useless.

(brick) · (brick) **Join Date: Nov 2003** 05-13-2004, 9:31 AM

This has been discussed a lot on this board. You can check the archives for more info, but this is how I understand it. A second battery will only provide extended play time when the boat is turned off. On the other hand, if your accessories are exceeding the capacity of your alternator, you will need to upgrade the alternator. Battery shack can provide you with a high output marine alternator for your boat.

duncans 05-13-2004, 11:07 AM

I see what you mean. I originally did a search but didn't know what to search for. This time around I found a whole bunch of info. Looks a little more complicated than I had hoped. Oh well time to start studying.
Thanks Tim,

(sup208) · (sup208) **Join Date: May 2004** 05-13-2004, 11:50 AM

I did it very easily and inexpensively on my 2001 calabria. Go to westmarine.com or some other marine suply store and get a perko battery selecto switch. You hook the grounds of the two batteries together and hook your boat ground wire up to one of the batteries. The the positive of each battery goes to its own terminal on the switch. There is another terminal that the boat posistive hooks up to. The swith has OFF,1,2,ALL. This allow you to run off of bat 1 , bat 2, or both. It also allow you to disconnet both batteries with the turn of the switch. When running my boat, i set the switch to all and let both batteries charge. When we stopped to relax I switched to 2 and used the stereo. If 2 went dead that was OK because I alway had 1 to start the boat with, except for the day i got the bright idea to switch to 1 and continue playing the stereo. Anyhow that is probably the simplest and cheapest method. You can put the automatic isolators in for a few extra bucks. I also used 4 gauge audio power wires for all my connections becasue it is flexible and much more easy to work with than battery wire. Hope that helps

jimmydager101 05-13-2004, 1:32 PM

Hey,
I was wondering if you could hook up a starter battery and a deep cycle battery together like that. I am trying to do the same thing but I am a little confused. I have explained my problems on a post titled Boat problems, help please. If you have any ideas please let me know.
Thanks,
Jimmy

(882001) · (882001) **Join Date: Nov 2003** 05-13-2004, 9:01 PM

pt#4805 at skidim.com

(rodmcinnis) · (rodmcinnis) **Join Date: Sep 2002** 05-14-2004, 2:49 PM

Jimmy:

Yes, you can have a starting battery on "A" and a deep cycle battery on "B". Switch to A for starting, BOTH when the engine is running and B when you are sitting still.

If you don't want to bother with the switch and just want more battery capacity by connecting two together then you would be better off if the two batteries were as identical as you could get them: same type, same size, same age.