A bit of help with how I want to wire my canopy

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juzzbott
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A bit of help with how I want to wire my canopy

Unread post by juzzbott » February 5th, 2013, 1:05 pm

Hey everyone,

I've done a bit of a search, and I can't seem to find anything that clarifies things in my head, so I would just like to ask some advice...

First, some background. I'm currently building up a lift off canopy for my hilux, with the goal of it being completely detachable from the vehicle. To this end, I'll be adding a third battery to the canopy so that the fridge and lights be running when disconnected from the vehicle.

I currently have a dual battery system installed, with the second battery isolated from the main by a sidewinder automatic isolator, and this is working a treat. However, I'm just a bit confused with the addition of a second auxiliary battery (which will become a third battery when the canopy is connected to the car). I don't believe that I will require a second isolator between the second and third (canopy) batteries, as it's already isolated from the main starting battery. I want to run the batteries in parallel so that I am doubling the amp hour of my system while maintaining 12 volts.

How will the charging of these batteries work? Will it completely charge the second battery before charging the third? Or, because it's in parallel, it will charge both batteries at the same time? I have a standard alternator on the rig, will this need to be upgraded to facilitate the charging of the third battery?

Also, I am considering the option for having a 240v general purpose outlet on the side of my canopy. The reason for this is if I stop at a caravan park, or a camping area with powered sites, I would like to charge the battery in the canopy from the 240v, as well as run my fridge from the 240v.

I want to get a quote from a sparky to do the 240v work obviously, but just want to clarify what I want beforehand, so that there is no confusion... My current line of thinking is having a female 240v plug on the canopy that I can plug in the power lead at the caravan park from. This outlet will go to a projecta battery charger, which will be intern hooked up to the battery in the canopy. However, I was also thinking I should run the fridge and possibly a laptop charger from this as well while I am there. So, would I need a second outlet (inside the canopy) that I can plug my fridge into.

So I think the 240v will come from caravan park -> outlet on side of camper -> then from there connect to both the battery charger and second outlet to plug the fridge in? Will I need a female or male outlet on the side of the camper?

Sorry for the long post, and I hope it all makes sense...

Cheers,
Justin

mydmax
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Re: A bit of help with how I want to wire my canopy

Unread post by mydmax » February 5th, 2013, 2:12 pm

Juzzbott
G'day justin.
Your paralleled batteries should charge quite ok but will of course take longer to charge because of the extra capacity.
Once the main battery is charged, usually within 5 mins of starting, nearly all the alternators output is available to charge the aux x 2. Unless you batteries are many hundreds of AH in capacity all should work OK. Presuming good earths/connections and suitable sized wiring and connectors are used.
It means the same alternator is running for longer and if flat, your alternator should be able to deliver sufficient current without the need to get a bigger unit, unless you are going to be winching often.

Make sure you put a heavy fuse on the negative side of the aux batteries so if one or both are shorted to earth with a dead short fault, that battery will blow it's fuse, this just increases safety.
To fully cover short circuit protection many fuses are needed in lots of places.

If a long run to your aux batteries, you may need to make sure the alternator output regulated voltage is high enough and some after market diode wiring plugs are available to raise this up a little to overcome distance resistance losses.


You can use a DC/DC charger which multi stage charges the aux x2 units.

For times you are in a caravan park just run a lead and use a 240v multistage charger to keep batteries topped up.
Do you really need the 240v plug in the canopy?

whizzo
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Re: A bit of help with how I want to wire my canopy

Unread post by whizzo » February 6th, 2013, 9:54 am

Not keen on the fuse in the negative line of the battery.......a correctly selected fuse or circuit breaker in the positive lead of each battery and in the feed from the main battery should provide adequate protection...that is unless you want to crank or winch off the second battery...then fusesor breakers in high current leads are simply not practical.

As soon as you introduce permenent 240V wiring to a vehicle there has to be earth leakage protection, switchboards and all sorts of stuff....best to avoid any 240V if at all possible....plug dirtect into your charger thru a hatch with proper accomodation for the cable.

if you are lifting off your canopy.....do you realy need a third battery...juts fit the second battery to the canopy.

cheers

juzzbott
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Joined: December 28th, 2009, 2:49 pm

Re: A bit of help with how I want to wire my canopy

Unread post by juzzbott » February 6th, 2013, 12:48 pm

Hey guys,

Thanks for your help.

That makes sense about the charging, as they are in parallel, so al good there.

My vehicle already has a dual battery system in it, so I want to keep that there. That way, if I go for a quick overnight trip somewhere, I still have the option of not taking the canopy, but still reliably powering the fridge and lights.

The AUX batteries will only be used for powering the fridge, lights, accessories, so don't need to worry about winching or cranking from them.

OK, I wasn't aware of that earth leakage, I thought you could hook up the power cables with maybe a circuit breaker in place. Is there much to the earth leakage and switchboard installs?

Cheers,
Justin

whizzo
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Re: A bit of help with how I want to wire my canopy

Unread post by whizzo » February 6th, 2013, 2:04 pm

As soon as you screw something 240V to a vehicle it becomes "a caravan installation" for the purposes of the electrical regs.

Serioulsy hundreds of dollars.....

240v inlet, with a weatherproof flap.
earthleakage circuit breaker either combined with or seperated curcuit breaker.
all outlets double pole switched
all regs concerning weather exposure apply
all metal parts of the body need to be bonded to the mains earth connection
All sorts of insulation, mechanical protection and clearanace specs
AND all certified by a full ticket sparky
AND if you sell or transfer rego, a certificate of test is required.

Y cant simply put a socket on the outside and a powerboard on the inside......definitely illegal...although plenty do.

soo much easier to do everything at 12 volts except the battery charger and plug that in direct.

cheers

juzzbott
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Joined: December 28th, 2009, 2:49 pm

Re: A bit of help with how I want to wire my canopy

Unread post by juzzbott » February 6th, 2013, 2:26 pm

Thanks for all...

Definitely didn't want to just run a plug and a power board, but that is pretty excessive for my use, so I think I'll settle for a weatherproof flap I can feed an extension cord through to plug into the battery charger.

Thanks mate :)

oznevil
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Re: A bit of help with how I want to wire my canopy

Unread post by oznevil » April 7th, 2017, 11:16 am

Hey Juzzbot,

I know this is an old thread, but I have just bought a lift off canopy and am wondering how you got 12V power into your canopy from your alternator/dual battery setup.

By this I mean, what kind of connection from car to canopy did you use? (Any Pics?)

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