The Official Dual Battery Thread

[TX.X-30 fan]

If you want a bullet proof system this is it!



Alt.' regulator and echo charger for the starter batt/house.

They offer all sizes of systems, you may not need the 150amp I use so calculate the draw and your done.

All I added to this set-up was (2) 2400 amp/hr kinetics agm batteries to run the stereo. I have never had a problem, run the stereo swimming for hrs. Starter batt. is always full.

These are reliable systems used on yachts.

[Ric]

Originally Posted by unclefud

Diesel,
Found your post while trying to find info on installing dual batteries on my Cobalt. Needless to say, I am not electrically inclined and am not famaliar with you term "head unit" in this article.
Thanks for your reply,
Unclefud

welcome fud, some people speak a little bit suggestively around here and I speak for all of us when I apologize for diesel using that type of reference in his posts

[TX.X-30 fan]

Probably got one of those eyeball pm's in the old in-box.


Not that I have a clue what that means.

[VOLFAN]

I have quickly glanced over this thread. Let me know if what I have found is correct.

Only use the same type battery?
I should in NO way use a starter battery and a Deep Cycle battery together?

(Optima highly preferred)(Where can I get one?)
Which two would be better and keep your Acc.'s going the longest and still be able to start the boat? 2x deepcycle or 2x starting?

Ther Perko switch is not that great of an idea the relay is better?

I have just installed an Amp and Sub in my boat and it killed the battery in about 2 minutes. Seems the boat has a low voltage shut off, because when it got below 8 volts it kicked everything off.

[rwoznock]

One of the first things I did when I bought my Maristar last year was put in a stereo with power amps and added another battery with a Perko switch. The problem with mine was the Maristar has the electric pump to raise the motor cover and thats wher I mounted the Perko. For 1000 reasons, sometimes we'd forget to turn the switch to save the extra battery and played the stereo all day without running. There were a few days where be barely had enough juice to start the boat! I found this thread and sought out to buy the relay. I'm in PA and I had trouble finding this part. All 6 of the auto part stores I went to told me they stopped making this device, but one place crossed it to a new number by another manufacturer. Advance auto had 1 of these left which was in Kentucky, so I had them send it up and I installed it yesterday. Thanks to Desiel for his knowledge on this project! IMO the Perko switch does a good job if you remember to keep switching it but this is definately the way to go. Anybody need a Perko switch? LOL!

[VOLFAN]

Ok I am have yet to buy two batteries for the boat. I am getting ready to come off the hip to buy them. I have heard you guys rave about Optima batteries. My question is why does it say 55 Apm hours on the Optima and the battery almost a 4th of the cost says 115 amp hours? Am I missing something?

Also I have added a temporary setup for now.
I got a Rockford Fosgate punch 100 (old school amp) pushing a 12" sub
and another small amp for the tower speakers.

Do you think I will will have any problem out of the alternator?

My plans are to add two optima D34M batteris. The cheapest I have been able to find these is for 155.00 a piece. Is that a good deal? Or can I find them cheaper somewhere else?

Also I am going to go with the Perko switch, because I have no idea how to run the wiring from the back of the ignition swith through out the boat to the batteries for the relay that has been talked about.

[rwoznock]

Hey Volfan,

Think about the relay, it really wasn't hard I just took out the ignition switch and with a test light found the contact that was powered when the key was on and ran the wire down the side of the boat to the engine compartment and connected it. It really wasn't bad. If you really want the Perko switch, I could send you the one I removed. It's about 1 1/2 years old but it would only cost you whatever the shipping costs would be.

On the batteries, I went to the auto parts store and told the guy I wanted to see the marine batteries and I asked if they sold the optima's. He said yes they did and I asked him if they were worth the money? He laughed and said the owner of the store gets 2 every year for his boat. I said every year? He said yes. I figure I could buy 3 new $55.00 ones and take my chances! Let me know if you want the Perko switch.

Ron

[2000XPSD]

for the relay power wire form the ignition switch what is the easiest way to run it? i have a 04 x2 and the battery is under the spotters seat. I was going to run it up to the bow and then back down the other side but the seat pads are bolted (except for the very front seat which slides up) and i don't see an easy way of getting them off...and I can't stick my fat hands up there to feed the wire thru the looms.
any ideas...easier to find a source wire in the engine comp and run it up from there? anybody have schematics?

[rwoznock]

Hey Volfan,

I have two Rockford Fosgate amps in my boat, a 360aII and a 160aII and have no problems.

quick question that i am pretty sure i know the answer to it all ready but just makin sure. with the set up u posted at the very beginning of the post. Will it be fine if one of the batteries is a different size/brand then another?