What size wire? Big 3? IBS-DBS Second Battery Install ’14 Taco

So I’ve already purchased the IBS-DBS dual battery system w/microprocessor (http://www.sierraexpeditions.com/index.php?l=product_detail&p=2074) as well as a blue top Optima deep cycle battery. My plan is to run the OEM battery under the hood until it dies and put my blue top aux battery in the bed of my truck.

My dilemma is that I don’t know what size wire I need to run to the second battery in my bed (I have a cap) and whether or not I absolutely have to do “the big 3” for this.

As far as the wire size goes, I’m reading some people saying I need to total the length of the power AND ground wire both coming from the bed. I don’t have exact measurements, but I’m sure it’s at least a 12-15’ run, meaning I’m looking at 24-30’ total. According to some of the websites I’ve consulted regarding length of runs and current, I need to go as big as 2/0 wire. I had only anticipated maybe 2awg, and there is a significant price difference between them as you probably know. But I may not be reading these charts right either… I total the length of the run, and then I must determine the number of amps running through it at any given time, correct? That said, where do I get the amp number? From the alternator?


In terms of the big 3, f from the decent amount of research I did before I initially purchased the IBS-DBS (though that was 3 months ago… yeah, this thing has been collecting dust on my desk for 3 months :/) I was under the impression that it wasn’t necessary. However, after poking around a bit I’m seeing some people say it is imperative because when the vehicle is on the alternator will have to charge both. Based on some videos I’ve watched, wouldn’t the IBS-DBS be considered one-directional without installing a winch? Meaning that it will charge the main battery and when that is full then charge the aux battery? Thus not overloading the alternator?


Also, on a side note regarding gases emitted from batteries… I’ve read conflicting information on the optima blue cap batteries releasing gases. I will be sleeping in the bed of my truck and also have dogs that ride in there, so if these gases are being released I definitely need to rethink my placement or get a new battery.

Thanks in advance all!

 

Over sized Good Quality audio wire will work perfectly fine
We have and use battery relocation kits that can handle 265Amps over 20 feet. Run your wire inside the frame rail front to rear and you should be perfectly fine
Do your big 3 100%, toss the cap away and enjoy.
I have really good sources for cable so let me know how much you need and i can get you exactly those lengths cut and shipped

 

Thanks for the reply manethon!

So I will definitely do the big 3, but I still am not sure what wire size I'd need to use for that and the second battery run? Something that may be pertinent to this is I have an audio system that draws about 1000w RMS. Also, I would like it setup to allow for a winch if possible in case I add that in the future. My understanding is that you'll need the power of both batteries and the alternator for that depending on the winch size, right?

I did find a chart and calculator about size, but do I base the amps on the chart to my alternator? The battery? How would I factor the winch into this? Also, the calculator I'm looking at shows how much of a voltage drop there will be based on what I put in. What is an acceptable/ideal voltage drop? <3%?

As for buying the wire from you, I'm certainly up for that as long as you ship quick.

 

thats not a problem, i can pull from my associates
Over sized 1/0 is all you would need but on should do a cost analysis of how much 2/0 vs 1/0 is for the lengths you need. If you do the big 3 and run sufficient size wire for the winch it should be able to run just fine off the front battery but having the capacity for the rear won't hurt.

Basically speaking, when the truck is running you want to be able to pull off of both batteries but of the truck is off just one. A 500a isolator should do the trick for that, then i personally also put a big circuit breaking across it so that i have the ability to use both batteries if the truck is off in the odd situation.