1989toy4wd

I was thinking about putting dual batteries in my truck, as the winch takes a huge load. I have an optima red-top in there now, and it does its job, but soon I am going to be doing lights, air horn, etc.

Now I searched and read about isolators and such. But I have a couple questions:

1. Do you really need an Isolator? I read IAMSUPERBLEEDERs thing about them and he isnt running one. If I read correctly they are supposed to prevent both batteries from running down right??

2. If you do run one, does the alternator charge the aux one up too?

3. I have a pickup, would it be okay to put an extra one in the bed in one of those battery boxes?

4. What guage wire would I need to put one in the bed?

I would run the one I have now for the engine, and maybe put a blue top in the other one to run my winch and accesories. What do you think?

iamsuperbleeder

well about the isolator, I looked at it like this; 12v diesel trucks have 2 wired directly together from the factory, so I honestly didn't see what the problem would be

one downfall to not installing an isolator is when one battery up and dies, it'll normally take the other down with it.

2) yes the isolator let's the alt charge the aux battery; it removes the connection from the battery to the rest of the truck when the ignition is turn off

3) you definately want to mount the battery outside of the cab, so a battery box in the bed would be a good spot so long as you mount it securely. I decided to just mount mine in my tool box; it was convient and hidden

4) I ran 4 gauge all the way back, and wraped the entire length in wire loom. for extra protection, I put a large fuse at either end of the cable right at the batteries in case of a short. For those fuses I used a basic amplifier fuse block, as you can get fuses for them for 40amp all the way to 100amp, maybe 150-200, but I've been runing 80amp fuses in them right now, and haven't had any issue; then again, I haven't really pulled a hard load on them yet; sure I've jumped peoples vehicles off, but I haven't ran a winch under a load or had 400watts of lights running off the truck either.


I haven't had any issues at all running my setup without an isolator, but, I would recommend one. I plan on installing one in the future when I get my MC front bumps and new winch. I'm sure a lot of people are go to insist that you HAVE to have an isolator; truth is, I'm proof that you don't HAVE to have one, BUT, even I will recommend using one

Hayes

The point of the isolator is to keep both batteries from dieing simultaneously, right?

Ask yourself this question, would you rather have it and not need it, or need it and not have it? If you have one, and you never have any problems, what's the harm? If you don't have one and both batteries die on a trail, way back, when you are alone...there's the harm.

That's my two cents.

-Hayes

Flash319

If you wire batteries in parallel then they act like one battery. You will always get the average of the 2 batteries because if one is discharged more then the other the charged one tries to equal out the dead one ( thus putting a load on the good battery). SO if you have a crap battery with a good one you will end up killing the good one. This is the idea behind the isolator. If you put 2 new batteries in at the same time I would not use one. The batteries should degrade at the same rate and you will not have a problem.

Bushwhacker

Hi gang, theres a leisure battery fitting guide here if that helps....
http://www.showmesome.info/hilux/workshop/battery.htm

iamsuperbleeder

precisely, and I did the setup with 2 Red Top Optimas, both about a year old that I got second-hand used. Now when they go, I'm going to replace both of them with brand new Red Top's at the same time

I like that simple relay idea... not a bad solution; cheap and easy!

Bushwhacker

I fitted this set-up to my truck and it works well. The leisure battery gets charged only when the engine in running and it's isolated when the engine is off. So if the main battery dies, the leisure battery can be used to self jump start.

1989toy4wd

Okay, that answered all of my questions, itll be a while but I will be doing that later!

bigt

TOYOTA STOCK DUAL BATTERIES!!!!!!!!

Bushwhacker

My engine compartment looked exactly the same as that last year, but I needed more power to get up all the steep hills around where I live so I fitted a V8.

iamsuperbleeder

booo diesel

scuba

good read bushwhacker !!

Hayes

no one likes a showoff.

Jay351

You have no idea how much I hate you! I want a 1uzfe!!!! ..........

TNRabbit

Do you have a stock alternator? Try getting yours rebuilt by Boyle Future Technology (search here for phone/address); they do an awesome job for under $200 shipped both ways. Takes a stock from 60 amps max to 90 amps at idle & 135 amps max. I love mine!

934rnr

I agree as well it's easier and far better to compensate the addtional voltage drain to upgrade your charging capability first.
Then do dual batteries if necessary at a later time.

nickthegreek

so i have a 93 4runner and wanted to do the same thing, im totally new at mods so my first port of call is finding a god spot in the truck to fit the deep cycle, and I'm already stuck. Theres no room whatsoever under the hood. I've read that the battery needs to be vented, but also been told that they don't always need to be. Can anyone clear that up for me definitively? and then where is a good place to fit the second battery since we dont have an open box and the bay is full? thanks for any help on this.