[magnat]

I am after options on fitting a Dual Battery system to an 02 XL-7..

Either I am not looking creatively enough ? or there doesn't seem to be any room for another battery under the bonnet. I want to try and keep everything where it is if possible..


The Dual battery Isolator will be a Projecta 150 amp.... So wiring is not going to be an issue.. but locating a second battery unit will be..
110ah is desirable to keep the fridge running and lighting LED strips at night..
I don't particularly want to have to Install the battery in the cabin space as it already gets pretty full with Double Swag and the rest of the gear for the Kayak and camping gear..

And I don't really fancy mounting the battery UNDER the car as the ramp over angle is not exactly the best..

So if you have managed to fit a Dual battery system to an XL-7... Pics and how you did it would be great..

[murcod]

I had two 23Ah batteries paralleled together, they lived under the LHS middle row seat in a container. They would slide in under the bar that you lift to move the seats fowrad/ backward and once that was released down again it was low enough to stop them sliding out. The controller was in the engine bay with brackets made up to bolt it onto existing mounting points.

There were dual battery trays made by Piranha that fitted a small battery in the engine bay, but you'll be struggling to fit 110Ah anywhere except the cargo area.

[fordem]

If the 02 XL-7 is anything like the GV of the same year, there should be enough space under the right seat, center row to take a second battery without affecting the break-over angle - just keep it above the chassis rail and you should be fine.

I've been tempted to move the main muffler and install twin fuel tanks under that rear seats, but, so far all I've done is think about it.

[magnat]

Oh what I would not give for a long range tank!...
Murcod.. I might look into that.. What were you running with the 23ah batteries ?

[murcod]

They were used external to the vehicle for lighting camp sites, the tent etc. I never had a fridge or anything similar running off them.

One other thing to consider is some dual battery systems also use the main battery for extra capacity, cutting it out of the circuit before there isn't enough Ah left for starting. You can fit a lot larger main battery with very little work.

I had a Optima 34R 800CCA / 50Ah in mine which was an easy fit (apart from the +ve battery terminal needing to be straightened out a bit.) That had plenty of space and I could have gone bigger (similar width and possbily 3-4cm higher and 2-3cm longer.) http://www.optimabatteries.com.au/brand/optima/

[magnat]

Yeah I got the opportunity to get a 40 litre 3-way fridge and I really need to get the power side of things sorted out before I do though

[buzbox]

I just plan on getting a larger battery. There's plenty of room for a truck size battery, I'd just get something like a AGM or Gell battery with the highest Ah. Optima seem to be the popular choice.
Otherwise like Mr murcod said, run them on the same side, you may have to move the windsceen washer and radiator overflow bottles, and bolt down a new tray.

[magnat]

Yeah gonna look into it.. I may have to redesign my Drawer system to accommodate a Battery box and mount a battery in the back...
Just not sure yet.. I mean it would be nice to go camping and be self sufficent for more than 3 days.. as Ice is not always available in the middle of BF nowhere..

[buzbox]

When it comes to wanting a dual battery setup just for the fridge, 1 large battery would do. I'm sure that sometime throughout the day you will be wanting to go for a drive so that'll recharge it.

Usually what I do is if most of the day is spent being lazy, at about 6pm start the car up and either go for a drive or let idle for 10-15mins. Enough charge to get it through the night. Yeah I've been caught out a couple of times with a flat battery but if there's no good samaritan around I park it on a slope (no not ontop an asian)

[Gwagensteve]

Is that 10-15 minute figure based on measurements or a guess? Reason I say that is that the amount of actual charge you're putting into the battery with a stock alternator at idle (beyond covering the needs of the car's electrical system) is typically very minimal based on my measurements.

My recollection of charge rates with a G16B vitara alternator were that there's not more than 10A of "spare" capacity at idle. (a G16B vitara consumes about 15A of current to run, the 65A alternator can't deliver more than about 25A at idle.

10A for 15 minutes won't cover the power drain of a fridge for long*. I'm aware an XL7 has a larger alternator, (85A?) but requires more power to run the car, and more power to crank.

I recall my 39L engel draws around 2.6A when running. Lets say it's duty cycle is 30%. (that's a guess but feels about right when the ambient is up.) so that's 20 minutes of running per hour. 20minutes per hour at 2.6A for lets say 12 hours - That's equivalent to 4 hours continuous running at 2.6A. To cover fridge use based on that, you'd need to charge at 41A above base load for 15 minutes to cover fridge use.

You'd need a very good battery to draw 41A, and a huge alternator to deliver that at 750 rpm.

I know I'm fudging the figures and they're all approximations, but fundamentally it should indicate that, 10-15minutes running is insufficient to put a meaningful charge into the battery.

I'd consider buying a DC clamp meter and checking current draw at idle after a lengthy drive. Use that as your base load. Then run the fridge overnight and in the morning fire the car up and leave it idling. The current draw is the maximum the battery can draw (or the alternator can deliver) keep the car idling until you see the draw reduce back to the hot/fully charged base level. I bet it takes a good while.

Please don't think I'm being negative, I"m just trying to put some figures around the practice of idling to top the battery off. I work on 45 minutes in the absence of a clamp meter to confirm.

Steve.

[buzbox]

Unlike other's on here at the moment I do appreciate your input.
My calculation is based on the time it takes to make a sandwich and have a beer So it's a complete guess of time.
When I have done that are usually an hour or so of coming back from a drive so it would already be at full charge.

[murcod]

Yes, 10-15 minutes at idle won't do much- especially for your average wet cell lead acid battery. You'll get a higher voltage reading straight afterwards from the "surface charge".

I've got a solar set up with 3 stage charging and it will supply peak current (up to 20 Amps) until the battery charge voltage reaches 14.2V. It then keeps it at that level for 2 hours before switching to float charge (~13.6V).

I know from running twin electric thermofans that the alternator can struggle to keep up at idle.

[oldschool]

I removed the stupid plastic shelf in the back, and built in a second battery, with ply and marine carpet, next to it a Travel buddy pie warmer, the battery box also doubles as a spot for volt meter, outlets, chargers and solar reg etc.
Its shaped so that the 3rd row can still lift up and be used. And its not that high once the plastic shelf is taken out too.

[Chop]

With my NGV diesel I recently got, there is no room for a second battery. So I bought a supercheap battery box and an 80ah battery and whilst on my usual easter trip to the snowy's used my solar panel to charge during the day and it work well. Down the track I will put my smart isolator in and run an anderson plug in the rear to the battery box.

Fridge ran well off the battery box and solar combo, only issue was the controller/regulator on the solar panels stopped working. But it just so happened my mate who had the property had been given one from another friend who said I could have it and it actually worked better with that one hooked up.

[magnat]

Chop, Thats something I will look into aswell.. What panels were you running ?

[got_bar_work]

Im a fan of the ones that fold in half like a suitcase. My ute has a stock battery plus 160ah battery in it and the solar panel will run my 40 and 50 liter fridge non stop for days untill i drive somewhere. If u have solar u realy only need enough battery for the night . And dont forget u should only use half the battery capacity. Any lower and u will start to shorten its life

[murcod]

The only problem with solar is the output is highly dependant on the weather. I've got a 12V system set up at home with a 100A/h AGM battery and 240W of panels. I've seen peak charging currents of over 20Amps on bright cool days. Other days you can get next to nothing. You'd also need to move the panels around to follow the sun for best performance.

BTW there are a couple of companies who sell combined dual battery charge controllers with an alternator and solar input.

[Pico42]

No idea what the engine bay of an XL-7 looks like, but in case it helps...

We fitted twin batteries to a JK Wrangler recently. The way it worked was two optima type deep cycle batteries on their side stacked on top of each other. An interesting fit, but it did fit under the bonnet.

[Built4thrashing]

I have dual batteries in my 2000 GV. Start battery is now a red top Optima and deep cycle is a N70 size 110Ah.

Check my build or Bohulers build for details.

[ZUZUKI]

Ditto with my car - not an XL-7, but under the bonnet, it's the same as an equivalent year 5 seater GV wagon.
Cranking battery is a Red top optima on its side, in a tray I built more than 10 years ago (moved the washer bottle & coolant expansion bottle) & a 12" case size (N70) leisure use deep cycle in the original location against the firewall - with some reinforcements to the tray. An Exide Stowaway LCS27DC-97 give 97Ah of capacity, which is sufficient for 2-3 days of fridge run time.

B4T, is that 110Ah 12" case a flat plate AGM? Normally a wet cell (flooded) 12" case battery tops out at under 100Ah capacity.
I had a little crack in the original tray, before I reinforced it & a flat plate AGM would weigh a lot more than a wet cell.

Rgs, Michael

[Built4thrashing]

I run different batteries now from when i did the original setup.


Deep cycle is now a 100Ah Bond Deep Cycle.

http://www.ebay.com.au/itm/BOND-BATTERY ... oqg7nnKMcA