[PORL]

Whats the biggest 2nd batt I could fit behind the washer bottle after I move it forward?
Would I need bigger than a optima d51? Just running the usual off it
Radio,amp
UHF cb
Fridge
Awning lights
Compresser

Cheers

[royce]

Dual battery size is dictated by how long you want to run something from it, not the number of things

[PORL]

I see, thank you Royce

How long could I run a fridge and radio off a D51?
I know its an ambiguous question, I'm just looking for approx times,
Mostly be used for camping.
Anyone Using a d51 as a second batt?
Experiences?

[upgarage]

Check out the Delkor DC range of batteries
DC24 or DC27 might fit

Have you worked out what isolator you want to run?

My planned setup in the sierra:
Redarc SBI12 $88 delivered
Jaycar - cable, lugs..etc $20
Wingnut batt terminals $10 pair
Delkor DC27 $150

Total $268 for 80AH

[royce]

to my mind 24 hours would be as far as I would go with just your average waeco or engel compressor fridge
the radio and amp is hard to say, the battery can supply 41 ah/hrs, pretend its 41 litres

the radio and amp might consume 10 ah/hrs, so 10 litres per hour, so in 4 hours youve killed the battery, though it might be 5 or 20, depends on the amp size

also its bad to flatten ANY lead acid battery too far, so you really cant use all that 41 litres

complex ey

[PORL]

upgarage wrote:

Check out the Delkor DC range of batteries
DC24 or DC27 might fit

Have you worked out what isolator you want to run?

My planned setup in the sierra:
Redarc SBI12 $88 delivered
Jaycar - cable, lugs..etc $20
Wingnut batt terminals $10 pair
Delkor DC27 $150

Total $268 for 80AH

Where are you getting the redarc and battery from?

Thanks Royce that helped heaps

[royce]

If you can fit a battery as big as that Delkor in and have Optima budget look at normal AGM batteries, youll get heaps of capacity then

Also a 100w solar panel will help heaps if you are siting still

[PORL]

Great minds think alike Royce, I'm searching solar panels as I type. I'm going to make some cardboard mock batts and see what I can fit.

[royce]

there is a thread somewhere where a dude made up a tray and got a big battery in

[Blakey]

royce wrote:

to my mind 24 hours would be as far as I would go with just your average waeco or engel compressor fridge
the radio and amp is hard to say, the battery can supply 41 ah/hrs, pretend its 41 litres

the radio and amp might consume 10 ah/hrs, so 10 litres per hour, so in 4 hours youve killed the battery, though it might be 5 or 20, depends on the amp size

also its bad to flatten ANY lead acid battery too far, so you really cant use all that 41 litres

complex ey

you will also find that most battery that Ah they can supply can only be supplied if its running at a certain amperage. IE you would think a 50Ah battery could run 10A for 5 hours but say you run it at 50A you would expect 1h but in reality you will get no where near 1h out of the battery.

that stated Ah of a battery yes it relates to Amps per hour expected out of a battery but that rating is at a certain discharge current.
you will find at lower discharge rates the battery will actually exceed that Ah rating.

In other words the higher the discharge rate the Lower the Ah rating of the battery becomes.

This is for battery banks but it still gives you a general idea of how to choose a battery

http://www.batteryweb.com/pdf/inverter_ ... ng_faq.pdf

[Fatzook]

royce wrote:

there is a thread somewhere where a dude made up a tray and got a big battery in

Zukenutter and bugsta have both done this.

[upgarage]

As per PM

redarc readily avail from ebay for $88 delivered. 3 sellers with same price
delkor from yhipower canning vale

[PORL]

Cheers everyone for the replies

[Mike57]

I have a D51 as the main battery and just got another one as the secondary battery. I have not fitted the second battery yet but I can tell you that it can run a 45 litre Techni Ice Fridge at 3 degrees over night with an ambient temperature of about 25 degrees and still start the car in the morning.

[PORL]

That's pretty good. Any radio time with that?

[Mike57]

No just the fridge left running in the garage overnight.

[jimmy91]

i put a optima yellow top D31A in my jimny in the back, have done no more then 5 hours driving since thursday morning and my fridge is still going since then.

[Scales]

Fatzook wrote:

royce wrote:

there is a thread somewhere where a dude made up a tray and got a big battery in

Zukenutter and bugsta have both done this.

My rig too.

I got a SLA battery in mine, its pretty big physically and barely fits. I run the fridge for overnight and then some without a drama with stereo also, just make sure your fridge low-volt cutout is set right. All my other auxiliary crap runs off it too (inc winch) but I usually have the engine running when any of that gear is on so that really doesnt count.

Dont put a deep cycle in if you are considering a winch. they dont like it.


EDIT:
Did some digging and found my old build thread.
viewtopic.php?f=14&t=23684&hilit=dual+battery

Just make sure you put big panel washers to reinforce the mounting points. mine ripped out at one stage... she wont again though!

[gvzookdriver]

What size cable does everyone use? And where do you get it from ?

[jimmy91]

I'm using a projecta kit. It's the $150 one and wiring is 8 gauge

[Scales]

My brother got me some welding cable, works a treat.

as for isolators I recommend redarc. SO happy with mine. Zero hassles

[Blakey]

gvzookdriver wrote:

What size cable does everyone use? And where do you get it from ?

i think most people use about 25sq mm cable.

and a good place to get some is springers, they are a solar shop and sell many sizes cable and gear for battery installs.

http://www.springers.com.au/

[Benz]

I have found cable for car amps to be much cheaper.

guys at the auto parts shop said it was cheap because the sell so much more of it.

It's that really fine stranded stuff and often has a clear insulation.

Not sure if it's bad to use it but haven't had any problems with it so far.
it's very flexible because of the fine strands but can be pain to solder.

[upgarage]

Jaycar

[Scales]

I'd be very very careful about using car stereo cable. The insulation is not as good, and I doubt the conductor is up to the task of delivering that sort of current either.


Buy what cable that is designed for the task.

[royce]

Scales wrote:

I'd be very very careful about using car stereo cable. The insulation is not as good, and I doubt the conductor is up to the task of delivering that sort of current either.


Buy what cable that is designed for the task.

Umm the whole point of the stuff is so it can deliver a whole heap of amps.

It will work just fine but like all cable you must size it properly, 8 gauge would be fine for underbonnet setups with a conventional battery that wont charge fast but if you are using an Optima or AGM then you should run bigger

But then if you cant find welding or battery cable cheaper than Amp cable you need to look harder

[Blakey]

Benz wrote:

I have found cable for car amps to be much cheaper.

guys at the auto parts shop said it was cheap because the sell so much more of it.

It's that really fine stranded stuff and often has a clear insulation.

Not sure if it's bad to use it but haven't had any problems with it so far.
it's very flexible because of the fine strands but can be pain to solder.

you will find unless it says OFC on it then its aluminium cable that's copper plated. it cannot carry as much current for size.

yes you can use it but you have to be weary of what it can carry most of the time its cheaper cause its not pure copper cable aluminium cable is heaps cheaper then copper if anyone tells you its cheaper cause they sell more is lieing.

but you can use it there is nothing wrong with using it.

if you go get proper battery cable or welding cable then it is pretty much always going to be pure copper cable.

as for insulation size its ~12V the insulation could be extremely thin. the insulation size is mostly for physical protection.

also for about 100A you would want to be looking in the cable size area of about 16mm or equivilant of about 5 AWG unless it was under a meter or 2 long then you might get away with 10mm or 8 AWG.

With cable your always better going bigger then you need, better to go overboard then to not have big enough.

[Benz]

yeah says OFC.
is 4 gauge stuff

I guess I didn't look everywhere in town for cable but for me that takes more time then it's worth

[Benz]

double post...

[Scales]

I realise about the amperage in the car stereo world Royce... However my main point is that you buy the correct tool for the job.

My neighbor has used AMP cable for his battery relocation on his xr6 ute (back into the tray). Had it there a few weeks and its already showing signs of insulation wear.


The cable could be cheaper because they source it from cheap chinese importers maybe? Is it REALLY ofc? Chinese rules are a bit less stringent on that sort of thing.


Your choice of course. I know what I would be doing/did do. Would hate to see an engine fire.