[ZookFan]

Hi Guys.. Bugsta helped me start on my dual battery system on the weekend...

Just needs some final soldering and crimping of the cables.., earth from optima batery, finish connecting the relay
up ect..

I have no idea about electrics

So could someone please help me this sat morning??

[Rusho]

Bugsta started it..he should finish it

[ZookFan]

He needs to have some time for his Jim

[Rusho]

ZookFan wrote:

He needs to have some time for his Jim

So what did he do? Put a tray in it and leave? Sounds like all the hard work is still to be done

[squibby]

I did mine myself and then got professional garage to tidy it all up after an engineer said I did a crappy job So here's what I learnt.

Earth from Optima to the body, on the passenger side around the bonnet hinge is a couple of existing bolts that can be utilised to earth the battery - negative (black cable) to the chassis.

Positive runs from + battery (Red cable) to your isolation switch or controller (red arc or similar) aux terminal. And then another red cable from isolation siwtch or controller Main terminal to your Main battery + terminal - or even to your alternator if you prefer. Although to the main battery is usually easier.

I mounted my controller to the firewall, if your new battery tray allows, mount it to that. It's a good idea to mount the controller high up to limit the water it ingests during river crossings and the like. Australian ADR's just say you gotta use adequately rated cable, and all cables need to be securely tied down at least every 30cm. SO make sure those cables have no length longer then 30cm without being tied down to something. Also use a plastic cable sheath around those cables as extra insulation to protect against friction over time. If you can try and put rubber/plastic sheaths over all exposed + positively charged terminals.

All the best!

[got_bar_work]

Have u got a hydraulic crimper for the main batt supply cables
U want at least a 16mm2 cable
I like to run the neg back down to the block to make sure it has a really good connection
It's a good idea to make a heat shield around the cradle to protect it from the extractors

[zukenutter]

Rusho wrote:

Bugsta started it..he should finish it

[Blakey]

got_bar_work wrote:

Have u got a hydraulic crimper for the main batt supply cables
U want at least a 16mm2 cable
I like to run the neg back down to the block to make sure it has a really good connection
It's a good idea to make a heat shield around the cradle to protect it from the extractors

is 70mm² adequate other then that i can go 95mm² or 120mm².

and 16mm² can only supply like 80A

would need larger considering you could be using a winch that uses up to 4kW which is like 330A

[got_bar_work]

I use have 35 & 50 on my vit 70 is getting pretty heavy
It's rated a lot higher then it is in as3008
U only have like 3m cable not like 100m so there isn't that much voltage drop
And u will never pull more then 250a and that would be for like a min not constant load

[ZookFan]

squibby wrote:

I did mine myself and then got professional garage to tidy it all up after an engineer said I did a crappy job So here's what I learnt.

Earth from Optima to the body, on the passenger side around the bonnet hinge is a couple of existing bolts that can be utilised to earth the battery - negative (black cable) to the chassis.

Positive runs from + battery (Red cable) to your isolation switch or controller (red arc or similar) aux terminal. And then another red cable from isolation siwtch or controller Main terminal to your Main battery + terminal - or even to your alternator if you prefer. Although to the main battery is usually easier.

I mounted my controller to the firewall, if your new battery tray allows, mount it to that. It's a good idea to mount the controller high up to limit the water it ingests during river crossings and the like. Australian ADR's just say you gotta use adequately rated cable, and all cables need to be securely tied down at least every 30cm. SO make sure those cables have no length longer then 30cm without being tied down to something. Also use a plastic cable sheath around those cables as extra insulation to protect against friction over time. If you can try and put rubber/plastic sheaths over all exposed + positively charged terminals.

All the best!

Cheers.. I will do the same

[ZookFan]

squibby wrote:

I did mine myself and then got professional garage to tidy it all up after an engineer said I did a crappy job So here's what I learnt.

Earth from Optima to the body, on the passenger side around the bonnet hinge is a couple of existing bolts that can be utilised to earth the battery - negative (black cable) to the chassis.

Positive runs from + battery (Red cable) to your isolation switch or controller (red arc or similar) aux terminal. And then another red cable from isolation siwtch or controller Main terminal to your Main battery + terminal - or even to your alternator if you prefer. Although to the main battery is usually easier.

I mounted my controller to the firewall, if your new battery tray allows, mount it to that. It's a good idea to mount the controller high up to limit the water it ingests during river crossings and the like. Australian ADR's just say you gotta use adequately rated cable, and all cables need to be securely tied down at least every 30cm. SO make sure those cables have no length longer then 30cm without being tied down to something. Also use a plastic cable sheath around those cables as extra insulation to protect against friction over time. If you can try and put rubber/plastic sheaths over all exposed + positively charged terminals.

All the best!

How hard is it to solder?? how do I know if I have soldered the wires?

[got_bar_work]

Wat r u soldering

[ZookFan]

Main - and + cables to the battery.. crimp then solder...

also solder the earth to the body as well I reckon

[Blakey]

ZookFan wrote:

How hard is it to solder?? how do I know if I have soldered the wires?

soldering is quite easy,

unless your soldering something like >25mm² then you will need quite a large soldering iron to even get the heat into the cable to solder it properly.

you will know if you have soldered it right as it wont look like a bubble of solder has formed on the cable, will look like they are part of the same thing with nice smooth

have a look here for how to solder, http://www.ee.ryerson.ca/~jkoch/solderi ... ering.html similar for lugs but obviously it will have the nice smooth part of the solder between the lug and the cable.

and you should tin your wires with solder before attempting to solder cables it will work allot easier when you go to solder the lug on

[Blakey]

ZookFan wrote:

Main - and + cables to the battery.. crimp then solder...

also solder the earth to the body as well I reckon

if you have crimped the cables then don't bother soldering, if its crimped properly the joint is just as good unless your doing audiophile stuff. there is absolutely no need to crimp and solder you wont gain anything from doing so.

and good luck soldering to the body, just crimp a lug and bolt it on.

to solder you have to get the cable and what you are soldering to have to be Hot enough to melt the solder, and you wont get the body hot enough to solder to it.

[TheOtherLeft]

Blakey wrote:

and you wont get the body hot enough to solder to it.

Shep could...

[got_bar_work]

There is no way u r going to solder a 70mm2 cable
Find some one with a crimper
I have a 12000 pound winch and a 120 a alternator
I have never seen my batt current go over 170a and I have to winch patrols up steps and stuff all the time( stupid patrols breaking down alll the time)
The winch only comes with 25mm2 cable so 70mm2 is way over kill

[Dr_Snapid]

I dont know if this wil help, it's my setup which I think should be pretty standard for a relay user. If you are using a controller it may differ. Also, my 80A relay is triggered from in side the cabin (isotated when shifter is in PARK) but how you trigger yours is up to you.

I bought a 8 gauge wiring kit for an audio amp. I use 60A fuses. It came with one fuse holder so I only had to buy one more. If anyone tells you you dont need 2 fuses, WALK AWAY. They have no clue. You must have one within 30cm of EACH positive terminal. (closer is better, mine could be closer than they are to be honest)

I also have some red cable running to the back of the car so where you see extra red cable off the aux battery, that's what it is, not part of the dual battery setup.

Some may say 60A isnt enough but remember all it normally has to carry is charge current. I have run my main battery flat before and started the engine off the aux without blowing the fuses. (i can do this by pulling the lever to neutral before turning the key, better than getting out with a set of jumper leads!)

[britvit]

^^^ I run a similar system to this running even smaller cable (4mm) & 20A fuses. I use two relays one triggered via a switch on the dash which is supplied from the ignition, the other is connected via the normally closed contacts and triggered from the starter. I only use the aux battery for light loads when camping, fridge lights etc. It's not perfect but it has been a cheap reliable system so far. If I needed to jump start from the aux battery I would have to use jump leads.

Dr_Snapid in the pic of your original battery you have got an unfused length of cable which looks like it is touching the battery clamp, if it rubs through the insulation you could be in trouble....

[Dr_Snapid]

Yep you are right Britvit and I have a length of conduit here to fix it. Thanks for pointing it out, i'd forgotten about it!

[got_bar_work]

If u have a winch I wouldn't go putting 60a fuse in there
U could be pulling close to 200a through there one day if ur main batt shits it self and u need to use that one alone to start or winch from

[squibby]

got_bar_work wrote:

If u have a winch I wouldn't go putting 60a fuse in there
U could be pulling close to 200a through there one day if ur main batt shits it self and u need to use that one alone to start or winch from

^^ what he said

Dr_Snapid wrote:

If anyone tells you you dont need 2 fuses, WALK AWAY. They have no clue. You must have one within 30cm of EACH positive terminal. (closer is better, mine could be closer than they are to be honest)

You didn't double insulate and you used a fairly low rating cable. You are wise to have fitted fuses to protect those cables.

If you are running a winch or using that aux battery as an emergency starter battery then just take the precautions of using adequately rated cable for purpose and double insulate cables. Obviously fuse anything that's running off the sytem (fridge, lights etc).

All depends on purpose of system, doesn't mean people have no clue because they didn't install a weedy system protected with 60A fuses.

My system (similar to many people on here not running fuses from Main to Aux battery) has been engineered NSW so there can't be much wrong with it. If I was just running a fridge then yeah I guess your system is alright.

[Dr_Snapid]

I'm specifically talking about the line between the 2 batteries. A single fuse only protects between the short and the battery that is fused. In a car accident your insulation can be compromised. A car burnt out the front of my house after hitting a motorbike, not a big impact but the cable running across the radiator panel was cut into. Only 1 fuse meant nothing to stop te other battery going up. It melted what was left of the insulation and started a nasty fire....

I did not realise a winch could draw that much (dont have one) . Is this true even with our small cars do you think?

[squibby]

Like I say, I'm not knocking your system, but don't make a hard and fast rule about the fuses. You won't find too many people who have fitted a fuse between the two batteries where they have instead opted for a well installed double insulated very large grade Cable because they are thinking about winches or starter motors.

But if they are installing 'relatively' skinny cable because they don't think they will ever draw big loads, then it is a wise thing to do I guess.

[britvit]

^^If I was using my aux battery for large loads I would still have 2 fuses. Just because lots of people don't fit them it doesn't make it safe.

There has been 2 car fires on this site since I have been a member......

I myself have had a car set on fire while driving at 120kmh on a packed 3 lane UK motorway, when I finally made it across to the emergency lane I burnt my hand badly, ripping the melting earth cable off the battery.
The clip had fallen off the bonnet stay which fell and shorted out on the starter solenoid..... Mini owners take note!

Dr_Snapid makes a good point, double insulation won't protect you in an accident. The fault current from 2 batteries would be enormous.

[Dr_Snapid]

Fuses are cheap. Put 2 if you can.

I'm not sure how you go about fusing a cable thats expected to support 200amps though. That's a lot of current, man! Can you get ratings that high? In theory you could run parallel fuses (three 60A in parallel would have a 180A rating) but i've never seen it done. I know every man and his dog but me has a winch and if they draw that much current there must be something out there in the way of overcurrent protection, a winch is right in the crash zone after all.

[Dr_Snapid]

The car audio fraternity do use fuses that big, apparently. Reading around I must admit it seems most people dont fuse winches. I'm a little surprised. I wonder if it's because winches tend blow the fuses because the draw is so constant for so long, and nobody wants an unreliable winch setup.

I tend not to want a fire in my car. But it's easy for me to say, i dont have a winch...

I guess this is off topic... although the OP hasnt mentioned what he intends to use his AUX battery for

[want33s]

I ran a fuse between my aux batt and winch as well as one between starter batt and dual batt controller.

I used two of the fuses pictured below but rated at 400A.
They will blow with any more than 40A dead short or up to 400A load.
Saved my car from melting when the winch winding shorted out.


Held in these...

Good value at only $13 each

EDIT:
Just checked and mine are 250A not 400A.
I originally had a ceramic 400 but when it blew I could only get 250's so that is what I fitted and never had another problem.

[britvit]

Bet that was the best $13 you ever spent

I have heard good things about these too.....http://www.keoghsmarine.com.au/product_ ... egoryID=37
There are also some large cheap circuit breakers available- I don't know if they would be any good with a large load like a winch.

Please everybody remember fuses are there to protect the cable not whatever you are running. Make sure you use the correct size cable for the load, just because some thing works does not mean it is installed safely.

If a cable is getting warm then it is over loaded, over time this will cause the insulation to become brittle and eventually crack up and fail. Cables with more strands and rubber like material in the insulation are generally higher rated- check with the supplier.

Keep unfused lengths of cable as short as possible, the fuses above can have one side bolted straight on to the battery terminal.

[Chop]

Redarc recommend a 100amp fuse on the starter battery side of the isolator and a 60amp on the auxillary battery side of the isolator.