Dual Battery Wiring

[irwazza]

Hey guys, I've done some searching but can't find the answer to my questions.

I just bought a ABR Sidewinder dual battery isolator. I have noticed that alot of people are mounting their isolators right next to there aux battery. Is there any benefit to this rather than mounting the isolator under the bonnet?
I would like to mount mine under the bonnet then run the output to my aux battery that is under my tray what will I need in the way of fuses / circuit breakers? 1 on the input of the isolator and 1 on the output of the isolator? Also what amperage should these be at?

Regards
Brenton

[Cowboy Dave]

Before I switched to a ctek charger I had my isolator mounted on the battery surround under the hood and ran the cables (big fat ones) all the way down the chassis rail and up into the tray. I put a circuit breaker at each end. Can't remember how big but I remember working out what I thought the isolator thing would put out before choosing them. Your main concern is voltage loss on a long cable run which is why I went with big cables. Now I have the ctek that's not so much of an issue and it's mounted on top of the auxiliary battery.

Derek from ABR will answer your questions about it - from memory he was some sort of sparkie by trade before he started his business up.

[Snooozy]

I Used 100A circuit breakers at both ends. like CD I also fitted a Ctek.
there is an update in my build thread (in sig line) -last few posts

[biggibbo]

I used a 150A circuit breaker at both ends.

[irwazza]

Anyone got any thoughts on the location of the isolator?

[Snooozy]

Mine circuit breaker is on the fuse/relay box


I only used 100A breaker as the cable I used was 14mm, it is rated about 120A, so gives me some protection against cable overload.

Use breakers to suit the cable, not just what's connected.

[MN GLXR]

Hey Snoozy, is that piece of paper in the pic to warn emergency services about the 2 nd battery in case of emergency?

[motoz]

Hey Snoozy, is that piece of paper in the pic to warn emergency services about the 2 nd battery in case of emergency?

I think that is a great idea and will be adding one to my setup.

Would you also install a keyed isolation switch on the cable?

[Snooozy]

Hey Snoozy, is that piece of paper in the pic to warn emergency services about the 2 nd battery in case of emergency?

Yep, that's exactly what it's for
As I an a volunteer firey I understand the need for this info to be available. In a vehicle accident disconnecting the power is one of the first things we do.

I have posted this previously but for those that have not seen those posts please make the location of aux battery available. If you have circuit breakers label them, that way it may not be necessary to cut the cables.

Mine is just a piece of laminated paper cable-tied to the battery box. Seems to last well.

[Snooozy]

Hey Snooozy, is that piece of paper in the pic to warn emergency services about the 2 nd battery in case of emergency?

I think that is a great idea and will be adding one to my setup.

Would you also install a keyed isolation switch on the cable?

I just use a circuit breaker at each end which can also act as a shutoff switch

[1ZERO5]

Does anyone know where is a good place to get wires and components for dual batteries in brissy is?

[Mattstruck]

Any Auto Elec will have it/order it for you.

But beware! This is expensive shizen

I used 6b&S, 13mm2. Ordered a 30m drum so I could wire the camper too. Cost me... $140 or $180 or something.

[reeldreamer]

Does anyone know where is a good place to get wires and components for dual batteries in brissy is?

Repco have a good selection!

[irwazza]

Abr have a Awsome selection. Not sure of where they are though. Online store is very fast. http://www.sidewinder.com.au

[Froggy]

Abr have a Awsome selection. Not sure of where they are though. Online store is very fast. http://www.sidewinder.com.au

Next to Bryan byrt ford, tingalpa.
There maybe more.

[dan.batto]

So it's not so much the wiring I want to know but I am looking at doing a dual battery,
I have the tray,
Does anyone know the battery size in the ml's? And what battery do you recommend for aux, rubbings fridge an a few small items,
As for management, I was going to go the redarc, smartstart isolator. And wire in a switch so as I can manually change it and crank off the aux if needed.
Thoughts on this? And recommendations on anything would be good.

Cheers

[david875]

I have a permanent fridge/freezer DZ50 in the tub and at times I run other items as well. I have a 115 amp deep cycle battery, and my advice is to put the biggest battery you can fit and afford. You need to calculate the power your fridge will draw, as probably this will be the most important item you will need to power and if you don’t run the car for a few days, the last thing you need is for your fridge stop working. I mounted mine on the toe bar, as I could fit a bigger battery there. With me size dose matter. The DZ50 will draw a max of 7 amp/hour and will maintain the temp at I think 1 amp/hour.

[Gezzansw]

I used a 140 Amp, 12V continuous Matson. comes as a kit.
Cuts in at 13.3V
Cuts out at 12.8V
Emergency parallel switch

Anderson Plugs & Cover to Camper trailer voltage at trailer battery is 13.2V charging

140 amp reset circuit breakers on all +ve leads. all from Ebay total cost under $200

used larger cable to reduce loss.

[Snooozy]

I wont go into re writing the whole thing

just have a look at my build thread (link in sig line)

page 2 & 4 if you scroll thru the other stuff you will find my aux batt system

[odie602r]

So I'm planning on upgrading my dual batt wiring and get an AGM battery to position behind the rear seat. Currently I have a redarc smart start mounted in engine bay.

I'll be using 6B&S cable to replace the 6mm twin cable currently installed. I know that I need to put fuses or circuit breakers "at each end", but I'm a little unclear as where where exactly in the cable chain, even after reading this and some other posts.

At the aux battery end, does the fuse go inline with the cable before it gets to the positive terminal, or does it go inline with cable after coming off of positive terminal and before heading to the devices?

At aux end, if I get a dc dc charger down the track, where does this go n relation to the fuse?

Finally (I think), at the main battery end, does the fuse go inline between main batt and red arc, or inline after red arc before proceeding on the cable run to the aux battery?

Someone also mentioned to me that a fuse at the red arc end wasn't necessary, as the solenoid would take care of things??

Thanks guys.

[big_bob_thefirst]

Regarding fuses, think of it as a shut off for each wire.

When leaving a + terminal, there should b a fuse or circuit breaker. So when leaving ur main bat, as close to the terminal as possible, I'd have a fuse. Then before u get to ur positive terminal in the back, also have a fuse. This wire between batteries is live both ways and of shorts out can over heat the wire...

Then going off ur aux battery u need fuses on the wires to the individual accessories.

What I'm doing at the moment is main bat , 50amp circuit breaker, 8mm cable, 50amp circuit breaker, dc charger, second bat. The run between dc charger and aux bat is very short and low risk of wiring breaking. I then have another short run to a fuse box, which I'll wire my accessories too. Think its tidier than in line fuses.

Not sure if the redarc acts as a fuse / circuit breaker.

[odie602r]

That makes it clearer for me - thanks.

Does anyone know if 6B&S cable will easily fit into those 4,6,8 fuse boxes? Or would the 6mm twin cable be sufficient to go from aux battery to the accessories?

[motoz]

6B&S is huge at 13mm2. I used that linking the batteries through the CTEK. For all the accessories running off the 2nd battery I've used 6mm twin core. Probably still a little overkill.

[odie602r]

Okay, so just thinking this through now practically:

Would the progression be:
Main batt -> fuse/circuit breaker -> red arc isolator -> cable run -> fuse/circuit breaker -> aux batt, then each accessory indivvidually fused (or through a fuse box).

OR given the run between main batt and red arc isolator is only about 30cm, would it go:
main batt -> red arc isolator -> fuse/circuit breaker -> cable run -> fuse/circuit breaker -> aux battery??

thanks again ...

[biggibbo]

option number 2