Battery isolators

[maxyedor]

OK, it's time for a dual battery set-up. I beleive an isolator is what I need, but none of the idiots at 4WheelParts could explain quite how they work, neither could the guys at West Marine or NAPA.

If I understand correctly I hook up my alternator to it and then each battery individually, each battery is seperate and the charge from the alternator is split to both of them, and if one is fully charged all the alternator's power goes to the other one.

I also beleive that the batteries are completely seperate, so I am okay to use my existing Exide spiral cell as a starting battery, and then run a brand new one as a winching, air compressor, fridge battery. Running batteries of different ages shouldn't be an issue. Also if I leave the fridge running for a few weeks and the acc. battery dies I will still be able to start the truck, and if I leave the stero on it will only drain the one battery so I should be able to swap them or use the good one to jump-start the truck.

Also any recomendations on a good one? I know Warm makes one rated for 120amps, but with the possibility of an upgraded alternator I'm thinking I should go for something closer to 175 amps.

Any imput, am I understanding these things correctly?

 

[antichrist]

Spend the money on a Schottky diode isolator. You'll get less voltage drop.
Here's a source for good infomation:
http://www.surepower.com
A lot of people use "isolator" and "separator" interchangeably. But they are different.

 

[fire1427]

All your writings are correct most are labeled "primary" for your starting running battery and "auxillary" for your second battery it will prevent crossdraining from the two allowing you to drain the one battery dead and still start and run ... If you plan on doing that be sure to get a deep cycle battery (I'm running an optima blue top for this)
I'm running a stinger 200 amp isolator from ebay

 

[antichrist]

I'm running a stinger 200 amp isolator from ebay

A lot of people use "isolator" and "separator" interchangeably. But they are different.

The relays (which you most commonly see on ebay) are separators, not isolators. Though Stinger does apparently make real isolators as well.

 

[hafaday]

hey guy, give these people a call www.wranglernw.com

the web site shows some stuff, but download the catalog and you can see all.. now granted they deal in American cars and trucks, also some rice burners but to me 12 volts is 12 volts. right? i know people that have used there stuff. they are happy
http://www.wranglernw.com/download/fullcatalog.pdf

 

[mkronmal]

I have the IBS Dual Battery System and like it a lot. It shows you voltage on both batteries, as well as the charging voltage. You can also manually pair the batteries if needed.

 

[ptschram]

I just tied two batteries together. Having different size and age batteries has not caused me any problems. I also use a deep cycle battery for starting and have for more than ten years now on my various vehicles.

 

[Mongo]

Like PT said, just wire them together...I've been running dual otpima's since I got my truck new in '01. The problem I did have was running the blue tops, I went thru 4 of them in 16 months, I now running yellows tops, which I had in since late '02...

 

[antichrist]

Connecting the two batteries is certainly an option, and one that I would suggest if you don't get an isolator with schottky diodes. If you can't up the voltage output of your alternator then the voltage drop caused by a "standard" isolator can kill batteries.

 

[maxyedor]

Anybody have wiring diagram of how to wire them together then, I think I know how to do it, but I'd hate to make them into a 24volt battery.

 

[Mongo]

i'll take a pic for you tomorrow...

 

[ptschram]

Anybody have wiring diagram of how to wire them together then, I think I know how to do it, but I'd hate to make them into a 24volt battery.

Positive to positive, negative to negative.

 

[lordkenyon]

You can check out this thread over on MO too..
http://www.muddyoval.com/forum/viewtopic.php?t=922&highlight=battery

Here's Brian's full writeup on his site:
http://www.domkenet.com/batinstall/index.htm

 

[antichrist]

Here's Brian's full writeup on his site:
http://www.domkenet.com/batinstall/index.htm

That's actually using a battery separator, not wired directly.

 

[maxyedor]

Thank's PT. Now I just need to go drop $160 on another battery, why are they so damn expensive?

 

[antichrist]

Thank's PT. Now I just need to go drop $160 on another battery, why are they so damn expensive?

If you're getting a spiralcell, get Exide, not Optima, assuming you're getting the isolator from fivespeed. Optima says not to use isolators with their batteries. Exide says it's fine with theirs. In the event there are any warranty issues.

 

[maxyedor]

I am goint to get the isolator from FiveSpeed, and the I may run dual batteries for winching and accessories (I have a lot) then a 3rd for starting. I've run an Exide spiral cell for the last 2 years and it's been great so I'll either get another Exide or a NAPA, no Optima for me, plus the yellow-tops cost over $200 around here, that's retarded IMHO.