Question about battery!!!!

Alright, heres the deal. I am about to hook up 4 tower speakers, a light bar and a sub in my boat. I will be running one 4 channel for my tower speakers and one two channel for my sub. My question is do I need to install a 2nd battery in my boat to run the speakers or would the one factory battery be sufficient? Also, if the 2nd battery is needed how would I go about hooking it up so it will not run down quick by the amps?

YES, a second battery bank is needed!!

You will need a Perko a/b switch like this one:


This allows for 2 battery set ups. Typically, position 1 is the starting battery and position 2 is for the amps battery(s). The switch is used to point to the charging system(alternator) to either battery or both while the engine is running and also determines which battery will do the starting. Some people also incorporate the use an isolator that will determine which batteries get the alternator charge like this:



I use 2 golf carts batteries for my second battery bank, see the discussion topic POWER.

Wiring all depends on how many batteries you will use.

David has it correct. You will need a second battery and 2 6V golf cart batteries are a great way to go with the stereo (Trojan T-105's in particular). Plus you get a nice secure feeling that your boat will start when you leave someplace you have been beached for a while.

I suggest looking into the U.S. Battery 2200 as well as the Trojan T-105. The U.S. Battery 2200 has thicker lead plates, will charge/discharge more cycles and it's a couple of dollars less. I paid 80/battery here in Houston for them. Also, look at this post:

http://www.wakeworld.com/MB/Discus/messages/65921/262496.html

To the lower right you can see the C100 combiner as well the Perko switch. It's a good combination of the 2 for manually switching between batteries if needed and automatically charging both batteries.

Skip the Perko and use a Stinger SR200 relay, no need to flip switches back and forth between battery banks. You just wire it to the ignition so it closes the circuit between the two batteries allowing them to charge when you turn the key. I prefer this system over the perko switch.

Read this post:

http://www.wakeworld.com/MB/Discus/messages/65921/347183.html

I will keep the perko and my manual peace of mind. I like the idea of automating most things, but this is one I will manage myself.

Thanks for the helpful info. Do you have any detailed photos of the setup or a diagram I could see. This will be my first time adding a second battery to anything and I want to get it right. Also what did you use to hold the 2 golf cart batteries in place on the boat?

All of the above combinations will work but they are not equal.

The Perko is the cheapest solution to combine more than one battery to a single circuit but you might not want to combine the circuits, even if you do the Perko is a pain because it's manual.

The isolator that is shown in David's post above requires a voltage offset to function so you will never get reach the voltage level of the main battery. If you use an AGM like an Optima for your main battery with a maximum charging voltage less than the maximum charging voltage of the golf carts your system will not charge the golf carts very well. In general it's not recommended to mix and match AGMs and Golf Carts (but I did in my system).

The stinger relay is not the greatest solution because it connects the dead batteries to the start battery when you turn the key on unless you have a manual switch to operate it. In that case it's no better than the cheaper Perko.

The combiner is a very nice solution. It provides charging priority to the battery bank of your choice. It does not connect the secondary battery to the charging system until the primary battery is nearly full.

I am currently running the little Yandina C100, with my primary being the starting battery and the secondary being the golf cart batteries.

Grant uses a much more sophisticated combiner, his primary battery bank is the stereo battery bank his secondary is the starting battery (I think).

If I had any trouble keeping my golf cart batteries charge up I would switch the priority of the charging circuits. But for now I like the delay the combiner provides before connecting the stereo bank to the charging circuit. I get a slight alternator whine when the batteries are low at idle. The delay is just enough to keep the batteries from connecting at times when I could hear the whine.

If I were to start over again I would skip the Perko and just use the combiner. For now my Perko is just a glorified terminal block.

Here is what mikeski drew out, it is good if going with the switch/combiner.

http://www.wakeworld.com/MB/Discus/messages/65921/Boat_Battery_Diagram-262940.pdf


The perko is manual but it won't let you down, unless you do something silly like turn it to off while the boat is running. My golf cart batteries supply power to my amps, I don't use them to start my engine. I also use smart 10amp chargers to charge my batteries at the end of the day and while storing the boat. I built a wooden box out of birch plywood and painted with kilz. I then secured it to the boat using 3m 5200 (this stuff is unbelievably strong and for marine use)The batteries are held in place by a bracket I made from a battery hold down kit. If you want to see pictures of that let me know and I will shoot a picture of the bracket, but I do have this for now:

I was talking to one of my friends today and he told me that my Boat was prob set up as a 12v system and said my alternator would not charge 24v. He said I would prob just have to charge the 2nd baattery when it gets low

That is why you have a perko. The perko will switch from one battery to the other without charging both, but you have the option of charging both.

Your boat is 12 volts. No one is using 24 volts

My set up is 12 volts. I am using 2 6 volt golf cart batteries. They are wired in series to produce 12 volts.

How complicated is the install on the perko switch? I know all this has been talked about before and I am sorry to ask so many questions. Is the perko all I will need or will I need and isolater as well?}

Not complicated.Basic skills to install it. Instructions come with the switch.Isolator is not necessary but makes things easier.

I am going to add some speakers/amps and will probably need to work something out similar to those shown in this post. I better start planning now though because I am not real electrical savvy...

I did a set up on my old boat like this and it seemed to work great.


I bought this kit for my boat at this place:
http://www.ase-supply.com/product_p/kit.htm

(Message edited by kenteck on December 14, 2006)

I talked to my local dealer today and they told me SC makes a dual battery kit that comes w/every thing you need to hook up a 2nd battery and it doesnt use a selector switch. Has anyone ever looked into this kit and ifso how pricey is it?