Second Battery

« **on:** January 05, 2008, 09:00:27 AM »

I am going to add a second battery to the boat strickly to power the stereo. Its not a huge system. Head unit, amp, couple of 6x9's. Just dont want to take the chance of a dead battery. Any opinions on switches or anything else? Thanks in advance.

Bob

« **Reply #1 on:** January 05, 2008, 09:08:39 AM »

You can use a 3-way battery switch...most marine shops carry them. Or you can just hook the second battery up in parallel to the main battery (i.e. positive - positive, negative - negative). Hooking them in parallel will double the current capacity of the electrical system plus the alternator can charge both batteries.

« **Reply #2 on:** January 05, 2008, 12:16:42 PM »

If I hook them up parralel will the radio draw from both batteries or just the one? If I decide to put in a switch, I can still have the alternator charge both correct?

« **Reply #3 on:** January 05, 2008, 12:42:42 PM »

Quote from: flytime on January 05, 2008, 12:16:42 PM

If I hook them up parralel will the radio draw from both batteries or just the one? If I decide to put in a switch, I can still have the alternator charge both correct?

By connecting two batteries in parallel, electrically the two batteries become 1 battery with double the current capacity.

The switch I believe has 3 positions: Bat 1, Bat 2, and Bat 1 & 2. The alternator will only charge the battery that is switched on by the switch.

« **Reply #4 on:** January 05, 2008, 12:47:29 PM »

Years ago I had a Dodge Ramcharger that I added a bunch of electrical crap to. I ran two batteries connected in parallel. What I eventually ended up with was 2 batteries half charged. I added a battery switch (just like the one Jetaholic is referring to) and the problem went away. I would never add a second battery without a switch, automatic switch or manual are available. I used a manual and it was awesome having it. I could use the stereo or winch and not worry about the thing not starting when I was done doing whatever I was doing.

« **Reply #5 on:** January 05, 2008, 01:02:33 PM »

A battery switch is good if you want to isolate the batteries, select which ones are being used (charged or drained)
but if you set up solenoids, you can charge both batteries, but only drain/use the batteries that the equipment is hooked up too.
Think of it this way... wouldn't it be nicer to always charge both batteries, but only use one for the starting/running of the motor
and the other battery for sterio or fridge (aka beer cooler) ?

check out this web page... answer all your questions!
http://www.bcae1.com/battiso.htm

-Rebel

« **Reply #6 on:** January 05, 2008, 01:16:30 PM »

Yeah what these guys said. For running the stereo while you're beached, it's definitely better to have 2 seperate batteries....one for starting and one for accessories. Once the boat is running it's a good idea to switch the battery switch to both so that they can both charge.

There is no way to charge both batteries off of 1 alternator and keep them isolated from each other at the same.

« **Reply #7 on:** January 05, 2008, 01:20:23 PM »

Quote from: Jetaholic on January 05, 2008, 01:16:30 PM

Yeah what these guys said. For running the stereo while you're beached, it's definitely better to have 2 seperate batteries....one for starting and one for accessories. There is no way to charge both batteries off of 1 alternator and keep them isolated from each other at the same.

Agreed, unless your worried about weight... then why have a sterio in the first place

-Rebel

also forgot to add... check out this article from Forkedup... very good info on subject as well

http://www.socaljetboats.com/index.php/topic,2323.0.html

« **Reply #8 on:** January 05, 2008, 02:49:37 PM »

Quote from: Jetaholic on January 05, 2008, 01:16:30 PM

There is no way to charge both batteries off of 1 alternator and keep them isolated from each other at the same.

I was talking to a stereo shop close by and dude said this is exactly how he wires up boats . So one battery only runs the boat while the other only runs the stereo .

-beerjet-

« **Reply #9 on:** January 05, 2008, 03:07:55 PM »

I have a switch. It has 4 positions on it batt 1,batt 2,all and off. Off works great to disconnect both batteries during long storage.

« **Reply #10 on:** January 05, 2008, 03:39:02 PM »

Marc,

Where did you find that switch?

Bob

« **Reply #11 on:** January 05, 2008, 03:51:30 PM »

It's just the standard one you find a t any marine shop or west marine for around $25.

« **Reply #12 on:** January 05, 2008, 09:05:08 PM »

Quote from: Jetaholic on January 05, 2008, 01:16:30 PM

There is no way to charge both batteries off of 1 alternator and keep them isolated from each other at the same.

Yes there is , its called a multi-battery isolator

. Thay have been used in boats and motorhomes for years for just this reason.
Heres an example. http://www.emarineinc.com/products/alternators/isolators.html

You can also use a duel output alt , like two alternators in one case.
http://www.boatelectric.com/91ddimensioncurves.htm

But in most cases the switch like marcsrollin showed will work fine and be verry trouble free.

« **Reply #13 on:** January 05, 2008, 09:32:22 PM »

Quote from: propless on January 05, 2008, 09:05:08 PM

Yes there is , its called a multi-battery isolator . Thay have been used in boats and motorhomes for years for just this reason.
Heres an example. http://www.emarineinc.com/products/alternators/isolators.html

You can also use a duel output alt , like two alternators in one case.
http://www.boatelectric.com/91ddimensioncurves.htm

But in most cases the switch like marcsrollin showed will work fine and be verry trouble free.

seems to me this multi battery isolator would be the way to go; no need to worry about flipping a switch; and easy hook up.

« **Reply #14 on:** January 05, 2008, 10:17:29 PM »

Quote from: wanabe on January 05, 2008, 09:32:22 PM

seems to me this multi battery isolator would be the way to go; no need to worry about flipping a switch; and easy hook up.

Although I haven't considered a second battery yet, it seems like a great way to do it. It works in motor homes, it'll surely work in a boat.

« **Reply #15 on:** January 05, 2008, 11:45:11 PM »

Did no one check out my first link? I mean really I go through all the trouble to show you all the options on one web page...
and no... you all skip over, read to the end and post your own little web site pagey thingy's

-Rebel

« **Reply #16 on:** January 06, 2008, 09:38:22 AM »

IMO the "guest Battery switch is the "hot set up" we always encourage dual batts , my flatty even has a back up fuel pump Last thing you want is to be "kickin it some where" get ready to go and .... dead battery cant say the isolater wouldn't work but just more to go wrong.We actually have a multi position switch that comes with a one,two,both,off/key lock for security Tom

« **Reply #17 on:** January 06, 2008, 10:05:21 AM »

Quote from: rebel on January 05, 2008, 11:45:11 PM

Did no one check out my first link? I mean really I go through all the trouble to show you all the options on one web page...
and no... you all skip over, read to the end and post your own little web site pagey thingy's

-Rebel

LOL

I did click your link; good stuff but because of the length, I started scanning instead of reading; the other link(s) was just an easier read for this simple mind

« **Reply #18 on:** January 06, 2008, 12:10:27 PM »

Quote from: jet boat performance on January 06, 2008, 09:38:22 AM

... dead battery cant say the isolater wouldn't work but just more to go wrong...

« **Reply #19 on:** January 06, 2008, 12:36:42 PM »

Quote from: rebel on January 05, 2008, 11:45:11 PM

Did no one check out my first link? I mean really I go through all the trouble to show you all the options on one web page...
and no... you all skip over, read to the end and post your own little web site pagey thingy's

-Rebel

Sorry, Mr Rebel sr !!!
I was bad, I did not look at it

. (propless hangs head in shame) You are the master of all things, and I should never have over looked your link ! It will never happen again

.

« **Reply #20 on:** January 06, 2008, 03:02:44 PM »

Undoubtedly get a Perko switch: One battery for starting, one battery straight to stereo.

This way you can isolate running the tunes on the beach and still have a battery to get you home. When you motor switch it to "all" to charge it back up. The only problem is you'll drop amps if you your beach time is too long putting strain on the amplifiers (lots of heat!.)

« **Reply #21 on:** January 06, 2008, 03:29:31 PM »

Quote from: propless on January 06, 2008, 12:36:42 PM

Sorry, Mr Rebel sr !!!
I was bad, I did not look at it . (propless hangs head in shame) You are the master of all things, and I should never have over looked your link ! It will never happen again (Attachment Link) .

LMAO...

almost PMSL it had pitures and interative stuff and everything

you are forgiven young one

-Rob

« **Reply #22 on:** January 06, 2008, 03:58:45 PM »

Quote from: propless on January 06, 2008, 12:36:42 PM

Sorry, Mr Rebel sr !!!
I was bad, I did not look at it . (propless hangs head in shame) You are the master of all things, and I should never have over looked your link ! It will never happen again (Attachment Link) .

Jeff you should prolly go spank yourself !!
Rob great post I just missed it T

« **Reply #23 on:** February 17, 2008, 06:12:41 PM »

Second battery update. My buddy in Bako got it installed over this past weekend and he says he is really happy with the way it turned out which is good news to me because he is more anal retentive than I am. No more worries about a dead battery after blastin the radio all day at the sand bar. Here is the finished product. Thanks for all the ideas everybody and thanks to JBP for dialing me in with the correct switch.

« **Reply #24 on:** February 17, 2008, 07:31:36 PM »

Ummm, your not finished, right?

flytime

Jetaholic

flytime

Jetaholic

hotrod56cars

rebel

Jetaholic

rebel

beerjet

Marcsrollin

flytime

Marcsrollin

propless

wanabe

GAWnCA

rebel

jet boat performance

wanabe

hotrod56cars

propless

Legal Chemistry

rebel

jet boat performance

flytime

propless