[b1nelly]

Howdy People.

Short story, I'm thinking of getting a dual battery set up into the back of the car with an anderson plug connection hooking the battery to the dual battery kit under the hood.

My concern is that if i remove the battery it will mess with the configuration of the dual battery kit and may lead to problems.

If i was to remove the aux battery (an ArkPak) and leave it out, do you lads think it will cause any issues.
Since its running through an the plug, there shouldnt be an shorting issues, but i'm not sure of if the dual battery kit will think there's a problem and burn out or let the smoke escape.

Can you guys see any issues with that setup?
Cheers
Nelly

[bumstein]

What sort of dual battery system are you running??

If you don't intend on leaving the second battery in-situ perhaps a simple battery isolator would work. Keeps the two batteries separated when it's in there and I wouldn't think it could cause a problem if it's not.

Someone with a bit more experience than me could chime in here but I think it would be ok. If it's a complex system like Redarc or something I just don't know how it would react

[royce]

Your average dual battery isolator wont know or care if the aux battery has gone missing.

But to blow my own trumpet, why not just build something that suits the purpose anyway, you'll get a lot better results with something like a CTEK 260s Dual mounted with the battery.
viewtopic.php?f=40&t=45208

[JayKay]

Hey mate,

I have just a Super Cheap Projecta Dual battery Isolator and remove my rear battery all the time with no issues.

[Mike57]

I have my Piranha isolator mounted along with the second battery in the back and it comes out with the second battery. I don't thinki it matters where the isolator is mounted unless the voltage drop across the cable running to the rear of the vehicle makes any difference and I have never bothered to think that through.

Mike

[b1nelly]

Thanks for the info lads.

The plan is to get a Narva or a powertech isolator from Jaycar and connect it to the battery in the boot.
The battery will have a decent amp hour so that I can run the fridge and camp lights.

When I get it started I'll post things up here and if i stuff it up and let the smoke out of the battery or the circuitry, I'll just do what every self respecting man does.....I'll blame you lot.

Cheers
Nelly

[grafy82]

There's a VSR isolater on eBay that is exactly the same as the jaycar / Narva unit. But it's only $39.00

[JayKay]

My rear battery is 100amp hour btw

[fordem]

Mike57 wrote:

I have my Piranha isolator mounted along with the second battery in the back and it comes out with the second battery. I don't thinki it matters where the isolator is mounted unless the voltage drop across the cable running to the rear of the vehicle makes any difference and I have never bothered to think that through.

Mike

I'd rather have the isolator mounted up front and as close to the main battery as possible - and this has nothing to do with voltage drop.

Most of the isolators I've seen are not fused (you can't "self jump" if they are), so an inadvertent short circuit could result in a fire - when the second battery is disconnected the isolator (if properly designed) should disconnect the feed - with the isolator close to the main battery, the longer cable is now "dead" reducing the potential for damage in the event of a short.

On a different note - if the second battery is going to be used for camp site power rather than winching I would suggest that you not use an isolator - go for a DC charger instead.

Isolators simply connect the batteries in parallel when charge current is available, this however does not guarantee the proper charging of the batteries - there are two issues to be considered, the first being that the batteries will probably be of dissimilar types - starting batteries do not last long when used in a "cycling mode" (long slow discharge cycles followed by a recharge) and different battery chemistries require different charge voltages. Even if the two batteries were identical, the second issue would still arise - you are "abruptly paralleling" batteries in different states of charge and therefore different terminal voltages - this can cause large currents to flow between the batteries and even discharge the main battery into the second battery.

[royce]

In theory this is the sound way to mount the isolator, however ive yet to see one that bothers to pay attention to the Aux battery before blindly turning on, the may exist, ive just never seen one

Also you can fuse the main line back (and should) batteries don't usually charge a billion amps on the end of a long lead, even big AGM's, also +1 (as I already stated) for a DC-DC charger, proper full charging for an AGM (alternator wont do it properly) doesn't care about where the input comes from or how much as long as its over 13.8 volts (ive charged my battery by plugging an old waeco power supply into the charger) you don't need to spend more money on another 240v charger to keep it topped up while you aren't using it, it also isolates the batteries and has a solar panel input, for when you realise how good it is to pull the battery and fridge out and leave it at camp with a panel running it, leave it in the car with solar and it will also top off your main when its got power to spare.

at $250 for a proper 20amp charger (over an alternator alone you can expect 10-20% higher state of charge, more fridge run time and longer battery life), battery isolator and solar regulator its bloody good value and will do a better job

[Mike57]

I have a fuse on both ends of the cable feeding the aux battery in the back. I don't trust the isolator to actually isolate when its needed.

My isolator only looks at the voltage on the main battery. If that is above something like 13.6 volts (I would need to check that to be precise) it will connect the auxiliary battery to be charged.

Both my batteries are the same D51 Optima yellow top. This is so I can swap them over if I stuff up the main battery winching from it. (not got around to adding the really heavy cable I would need to parallel them yet) I am aware that the alternator won't charge these batteries adequately so every three to four weeks I connect them individually to my CTEK charger. I am hoping that the occasional full charge will be adequate. Any comments on that theory Royce or Fordem? In my particular case because of the voltage drop on the cable to the rear I know the rear battery only ever sees about 14 volts when it needs 14.6 to fully charge.

I just took a look at the CTEK 250S DC to DC charger. Do these put out a constant voltage regardless of the input voltage range? What input voltage range can they tolerate? This might be a solution for the rear battery in my case. Any thoughts?

Mike

[Dan85]

I've just ordered a project a 150a isolator kit. Is it worth me taking a hit and selling it for the ctec? I plan on running solar and a deep cycle agm to power my Waco and some small led lightstrips

[b1nelly]

Yeh i agree Mike, Fusing both ends is worth it.
The battery pak i wanna get has a fuse in it, but thinking of cutting another one in.

I'm not sure that i need to worry about the different cycles for the batteries. A normal isolator works by cutting in and out, it doesnt seem to effect the batteries or people wouldnt be getting them in their cars for the last few decades.

As for setting up the battery with a solar charging system, I'm not sure about. I know that the ArkPak can be charged by solar by i'm not sure about any other systems. Sorry mate.

[royce]

Mike57 wrote:

I just took a look at the CTEK 250S DC to DC charger. Do these put out a constant voltage regardless of the input voltage range? What input voltage range can they tolerate? This might be a solution for the rear battery in my case. Any thoughts?

Mike

They put out the appropriate charge (they are 5 stage constant current, constant voltage, float etc) regardless of input voltage (providing its high enough to trigger it of course)

[royce]

b1nelly wrote:

I'm not sure that i need to worry about the different cycles for the batteries. A normal isolator works by cutting in and out, it doesnt seem to effect the batteries or people wouldnt be getting them in their cars for the last few decades.

And for decades people have been ruining batteries early, putting up with undercharged batteries and generally being ignorant to how much science there actually is in a lump of lead and acid.

Now we have the tech to overcome ALL those problems in a little box and its affordable, its madness to do it any other way, go see how quickly its been taken up by caravaners and so on.

[offroadjack]

depending what you want to run off your second battery,why don't you just get a waeco coolpower 36 portable deep cycle and a waeco RAPS RU2-12R unit hooked up to your main battery?
portable battery you can take anywhere and hook it up when needed without any dramas.
that's my set up and works for me, you can take your fridge etc. AND battery anywhere you want.
my waeco battery is over 5 years old now and no signs of loosing it's charge.
it has a display which tells you the voltage so you know when it's getting low and you need to hook it up again.
space is always an issue in a zook and this way I can take out the battery when I don't need it for more boot/cabin space.
my Raps is sitting under the driver seat always ready to hook up anything, and when I go out and take the fridge the battery sits either behind the seat or in the back depending where I go or passengers I take.
also, you can use any fridge on the RAPS unit

[Munster]

offroadjack wrote:

depending what you want to run off your second battery,why don't you just get a waeco coolpower 36 portable deep cycle and a waeco RAPS RU2-12R unit hooked up to your main battery?
portable battery you can take anywhere and hook it up when needed without any dramas.
that's my set up and works for me, you can take your fridge etc. AND battery anywhere you want.
my waeco battery is over 5 years old now and no signs of loosing it's charge.
it has a display which tells you the voltage so you know when it's getting low and you need to hook it up again.
space is always an issue in a zook and this way I can take out the battery when I don't need it for more boot/cabin space.
my Raps is sitting under the driver seat always ready to hook up anything, and when I go out and take the fridge the battery sits either behind the seat or in the back depending where I go or passengers I take.
also, you can use any fridge on the RAPS unit

Likewise I run Engel 56 amp hour battery with Engel charger wired up to my main battery, there is no room under the bonnet of the new GV's.

[sur5a]

http://www.arkcorp.com.au/c/502/battery-boxeshas anybody tried these ?

[b1nelly]

Yo Sur5a,

Thats exactly what i'm looking at getting, the ArkPak.
It looks after the battery by cycling through varying stages to maintain the batteries health and from what i've been reading, seems to be designed with the idea of taking it out of the vehicle.

Seen one the other day. good quality hard abs plastic and alot smaller than i first thought it would be.
with the addition of the inverter and lighter ports i think it would be a great things to have in a tourer thats also a daily drive.

When i get one, I'll let you know how it goes.
Nelly

[b1nelly]

offroadjack wrote:

depending what you want to run off your second battery,why don't you just get a waeco coolpower 36 portable deep cycle and a waeco RAPS RU2-12R unit hooked up to your main battery?
portable battery you can take anywhere and hook it up when needed without any dramas.
that's my set up and works for me, you can take your fridge etc. AND battery anywhere you want.
my waeco battery is over 5 years old now and no signs of loosing it's charge.
it has a display which tells you the voltage so you know when it's getting low and you need to hook it up again.
space is always an issue in a zook and this way I can take out the battery when I don't need it for more boot/cabin space.
my Raps is sitting under the driver seat always ready to hook up anything, and when I go out and take the fridge the battery sits either behind the seat or in the back depending where I go or passengers I take.
also, you can use any fridge on the RAPS unit

Cheers mate, Looks very similar to the Arkpak system with the addition of an inverter in the box for 240v connection.

Good to see these systems work then, especially since yours is 5 years plus.

cheers mate.

[b1nelly]

royce wrote:

b1nelly wrote:

I'm not sure that i need to worry about the different cycles for the batteries. A normal isolator works by cutting in and out, it doesnt seem to effect the batteries or people wouldnt be getting them in their cars for the last few decades.

And for decades people have been ruining batteries early, putting up with undercharged batteries and generally being ignorant to how much science there actually is in a lump of lead and acid.

Now we have the tech to overcome ALL those problems in a little box and its affordable, its madness to do it any other way, go see how quickly its been taken up by caravaners and so on.

You may just wanna have a read of the system i'm looking at mate, before you go blasting the horns.
I had a look at the one you tagged and whilst i can appreciated it, i think its a little over kill for what i'm looking at.

cheers tho

[sur5a]

b1nelly wrote:

Yo Sur5a,

Thats exactly what i'm looking at getting, the ArkPak.
It looks after the battery by cycling through varying stages to maintain the batteries health and from what i've been reading, seems to be designed with the idea of taking it out of the vehicle.

Seen one the other day. good quality hard abs plastic and alot smaller than i first thought it would be.
with the addition of the inverter and lighter ports i think it would be a great things to have in a tourer thats also a daily drive.

When i get one, I'll let you know how it goes.
Nelly

Will be interested to hear a first hand opinion on how these go,had my eye on it for a while,if the camping frequency increases i can justify getting one.
looks like a good bit of kit IMO

[royce]

b1nelly wrote:

royce wrote:

b1nelly wrote:

I'm not sure that i need to worry about the different cycles for the batteries. A normal isolator works by cutting in and out, it doesnt seem to effect the batteries or people wouldnt be getting them in their cars for the last few decades.

And for decades people have been ruining batteries early, putting up with undercharged batteries and generally being ignorant to how much science there actually is in a lump of lead and acid.

Now we have the tech to overcome ALL those problems in a little box and its affordable, its madness to do it any other way, go see how quickly its been taken up by caravaners and so on.

You may just wanna have a read of the system i'm looking at mate, before you go blasting the horns.
I had a look at the one you tagged and whilst i can appreciated it, i think its a little over kill for what i'm looking at.

cheers tho

I typed a bit response listing everything wrong with your idea but I guess you are one of these internet people that ask a question and don't want to be given an answer, good luck with your box.

[gregwatkins75]

+1000000000000 for Royce.

I looked at all options before settling on the CTEK and a 150a/h AGM battery.

Once installed it looks after itself.
Been in for a year with no issues, I haven't even looked at it!

If you shop around it even works out cheaper than the ARK pack.


Current set up runs a 45lt engle and a couple of led strips for 4 days without needing to turn the car on.
When it goes flat takes about 2-3 hours of driving before it's charged again!