Dual Battery Setups! Let's see them! Multiple Batteries Thread!

No, but it's not a bad idea ...

 

A LiPo battery maybe?

 

Motorcycle battery?

 

Are you suggesting it might interfere?

 

That's a lot of juice to be pulling through a small breaker. Honestly wondering how that works for you. 200amps vs 700-900cca

 

Fortunately, I have not had to try it yet. Maybe someday I will have that pleasure.

One of the reasons I chose that particular CB is because of its capacity. Yes, it is rated at 200 amps, but if you look at the
Bluesea chart on the page I linked to, bluesea says it will hold 400 amps for up to 10 seconds before tripping. Based on the chart, it looks like it'll hold 600 amps for at least 2-3 seconds before tripping. I expect that will be sufficient to handle the self jump.

 

That's good. I know, that's the same reason I use one on my winch. 600amps amps, I hope that's enough, but I would count on it drawing more although I don't know exactly how much is pulled for ideal/extreme conditions.

 

I have read that the 3.4L starter initial pull is ~300 amps but so many factors come into play, it is difficult to know for certain.

 

What are people using for wire loom for these projects. I have some 3/4" split loom like this

$34 WirthCo 27071 Black Battery Doctor Split Loom (3/4" - 100 Feet)

https://www.amazon.com/WirthCo-2707...qid=1480628058&sr=8-1&keywords=3/4+split+loom but it kinda sucks. Is there something better I should be using?

 

There are others like this braided and this spiraled but if you think split loom sucks... Maybe get the tool?

$26 Electriduct Wire Loom Insertion Tool Set for 3/8" to 2" Conduit Sleeving Installation

https://www.amazon.com/Piece-Wire-Loom-Cable-Insertion/dp/B00OKXP0C6

$7 Techflex PTN0.25BK25 Flexo PET General Purpose 1/4" Cable Sleeve, Black, 25 Foot

https://www.amazon.com/Techflex-PTN0-25BK25-General-Purpose-Braided/dp/B004UHJCFI/

$15 Electriduct 1/4" Spiral Cable Wrap Polyethylene Expandable Abrasion Protector Wire Sleeve - 50 Feet - Blue

https://www.amazon.com/Spiral-Cable-Wrap-Length-Color/dp/B01HDO2KF8/

 

Just FYI. If you go with the blue top optimas, you only get a 2 year warranty. If you choose the yellow top, you get a 3 year warranty.

I know the additional post is nice on the blue top, but with the milspec terminals you are using, you should be fine.

I chose to go for the extra year of
warranty personally. Just my .02.

running a bunch of power wire through the truck my only suggestion would be to add circuit breakers. We put a bunch of them in my setup. Probably overkill, but id rather go overkill then have shit catch on fire. Check McMaster Carr. They had some good ones for a good price.

And don't forget good terminal ends.

Luckily i had @Iggy. helping me. He is a wiring nut!

 

Like that? ^^

 

That's an insainly cool setup with battery in back, and dual compressor to boot!! Any write ups on your setup?

 

Does anyone know where to get good quality 0 gauge welding wire for a great price. I'm building a Triple battery setup just purchased two northstar 31m batteries while waiting for that shipment. I figure I'll get all my wires. 0 gauge welding wire is overkill but I don't want any voltage drop or resistance.

 

Initial spike in most systems is 700+ amps. I've seen 4cyl models pulling 750+.

 

I get welding cable from one of the local welding supply shops. They charge what most online places ask. If you search through Amazon you can sometimes trip across welding cable for decent prices.

FWIW, the way to save money is to ask your local guy for scraps. They'll often have random length pieces, whatever was left over at the end of spools and stuff. Talking a few feet here or there that they probably can't otherwise get rid of.

 

It's commonly referred to as 1/0 gauge. I used Crimp Supply. They have their own web site, but if you purchase it via Amazon, they throw in 5 copper lugs with each order.

 

I think it's important to point out that you're not saying a starter will draw 700A continuously. This is an example of an inrush current. Once spinning our truck starters are rated around 1.25kW (depends on which engine, cold weather packages, etc.).

After the first 1/4 or 1/2 second the starter will be down to drawing around 100A to generate the cranking torque.

This is an example of the current profile of an engine starter might look like. The inrush can be very large and you need to be aware of it from an absolute standpoint (it can arc or fuse contacts, for example) but for cable sizing it's the area under the curve and current duration that you need to consider as this is what causes heating issues, e.g. melting insulation, causing fuses and breakers to trip.


https://www.bluesea.com/resources/114

It's important to understand the distinctions between inrush, intermittent and continuous current and to know which is important in which context.

 

Yes. That's one of the reasons you want a battery isolation setup. The alternator does not care if the batteries are conventional, AGM, deep cycle, or a combination thereof. Don't know about the Blue Sea. I'm using a 200-amp Cole Hersee solenoid relay with a manual DPDT switch. Very easy and simple setup; also affordable. The biggest risk with this setup is forgetting to turn off the switch, which has happen to me. That just leaves the batteries connected together when you turn off the vehicle. Not a big deal over several days (as long as both batteries are functioning properly) but gong into weeks you run the risk of draining the batteries.

 

Nice. Getting closer to finishing my version of this, too.