Which battery?

Submitted: Thursday, Jan 16, 2003 at 11:53
ThreadID: 2983 Views:8722 Replies:4 FollowUps:20
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We have a 4.5L petrol GU Patrol and are in the process of setting up a dual battery system using a REDARC solenoid battery isolator (thanks Ozi). System is required to run a 39L Engel only for a max of say 2 nights between runs to charge the battery.

Trouble is when we got the auxilary battery tray it turned out to only accomodate a small battery (due to limited under bonnet space) - instructions say an N48, although both ARB and TJM reckon they use an N50 (same tray). We had intended to use a heavy duty battery rather than a deep cycle as we felt this would better suit our needs. TJM also mentioned a "dual purpose" battery. Main battery is a N70ZZL and we do not wish to replace it with anything else until the end of its useful life.

Now we are a bit stumped as to what battery we can get a) to best suit our needs, and b) to fit the tray. Any suggestions?

:o) Melissa
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Reply By: OziExplorer - Thursday, Jan 16, 2003 at 15:04

Thursday, Jan 16, 2003 at 15:04
Melissa a heavy duty battery will not last as long as a deep cycle battery,
as they are not designed to be cycled. There are batteries that will allow
a limited amount of cycling, but 36 hours is stretching the relationship far
to far. Limited cycling is basically considered a maximum 6 hour time frame at about 2.5aH to 3.5aH. Even with the expensive 'dual purpose' (term used *very* loosely* 10 hours at 2.5ah would be absolute max. ARB outlets for example promote the Exide Extreme as one of these 'dual purpose' batteries, but to date, I have not seen any information from Exide that backs this up. The Exide Orbital makes a vague reference to being 'dual purpose' by this comment:
Deeper Discharge, More Cycles
But Exide at least do quote a specification for this battery under those conditions. About the only manufacturer that does. Having some small insight into that technology, I can understand why they are claiming what they are, but as to life using the battery in that function - no idea.

At the end of the day, the way we are using these auxilliary batteries in vehicles, no manufacturer to my knowledge will give you any more than a sixth month warranty, except Optima. However, Optima don't make a battery your size and could not justify the price. You can buy 4 normal batteries for that price. Where an Optima would be good would be if you had the battery in the back of the vehicle.
Normally, depending on use and how you treat/use the auxilliary battery, absolute maximum life is 18 months and few get there, 15 months perhaps 40% and 12 months the norm. So now you can see why six months warranty is pretty standard. Taking a two year warranty car battery and sticking it in there will not give you a two year warranty as the battery would not last probably more than 4 to 5 months.

Not really smart to make an N50 battery tray size, as it is most definitely not what you would call a standard size for deep cycle battery. They should have advised you before installation what size and capacacity battery it would take. The more I see and hear of these 4WD shops the more I realise what shockers they are.
Exide make an ED4 which is just a battery at 55 amps at 20hr rating. 36 hours, no way. 24 hours, hmmm yes argh, possibly depending on ambient tempreture. A little deeper discharge that I would like to see.

Not very helpful I am afraid, but at least you know I have no vested interests.

When you say "for a max of say 2 nights between runs" I presume you mean Night - Day - Night morning drive off. Battery could need around 3 hours of driving to get fully charged.
I would suggest you get from Jaycar www.jaycar.com.au
Part NO. XC0116 $39.95
This would allow you to monitor your auxilliary battery voltage, and also see how cold the tempreture of the fridge is so you do not have the thermostat colder than would be needed, and hence dishcharge the battery more than is necessary.
next morning.
AnswerID: 11389

Follow Up By: Member - Melissa - Thursday, Jan 16, 2003 at 16:16

Thursday, Jan 16, 2003 at 16:16
Thanks for your reply Ozi. We haven't yet installed the DBS - planning to do this ourselves. 4WD outlets wanted $130-$140 for battery tray alone. Managed to get one 2nd hand but brand new for $60. This was when we became aware of the battery size. Despite the fact we'd had several quotes for supply and installation of a DBS from ARB, TJM, Opposite Lock etc (all too expensive), none mentioned the small battery size. Surprising because in all cases we asked for and were quoted both on a h/duty battery and d/c battery.

After taking delivery of the battery tray we thought we'd been shafted. A few quick calls to the aforementioned confirmed that we did indeed have the correct tray. All conceded that there is little underbonnet space in the GU's, thus the small battery. (Had we taken them up on their quotes we would have had a heart attack when we picked the vehicle up!)

This leaves us wondering if any battery that fits the tray is going to do the job we want??? Hubby was almost certain you can't get a (decent) d/c or h/d in an N50. Perhaps the 4WD places think we are stupid and wouldn't notice or perhaps they know something we don't???

I take your point about a deep cycle being better than h/duty but with many of our runs being only 3-4 hours we felt that the "longer to charge" deep cycles would always be "undercharged". Anyway, seems to be a moot point now.

Our campertrailer is equipped with a deep cycle battery (charged off mains at home or when in CVP) so for longer stays we simply transfer fridge from car to trailer after a night or two. We DON'T want to have to do this on single night stop overs.

Only other option we can think of is to utilise the large space behind the bullbar (normally where a winch would go but we will not be getting one) and get brackets and tray made up to enable us to fit a more standard size battery.

:o) Melissa
FollowupID: 6295

Follow Up By: Oziexplorer - Thursday, Jan 16, 2003 at 18:10

Thursday, Jan 16, 2003 at 18:10
Melissa as you can see these 4WD outlets have close to zero ethics, product knowledge and are really basically rip-off con artists. I cannot believe the extortianate prices they charge and they have zero idea of the truth. Used car salesman are saints and angels compared to the con artists 4WD shops engage. What really gets me is the absolutely blatent lies and misinformation they spew out. I cannot understand why people shop at them. You can *always* find a cheaper and often better product elsewhere.

Melissa a deep cycle battery takes no longer to charge than any other type of battery. The state of charge is what determines the amount of time it would take to charge it.

Behind the bull bar is not an ideal place for a battery from a vibration point of view, but with the amount of time a deep cycle battery lasts and the improved construction of batteries and vehicle suspensioin, I am sure it would survive 15 months. You could of course use 2 x smaller batteries, one mounted in the battery tray and one mounted behind the bull bar, but I am never in favour of using two batteries where you can get away with one. Two is also more expensive per aH than one battery.

If you want, you could always fit an Optima deep cycle battery in the back of the vehicle. They assure me two year warranty and you should get three years life easily out of it. they say.
However, the capacity is nothing exciting. They do have a new 80aH battery not yet on their website. I have received a fax on the battery and will download it tonight (I have mobile fax and data only)
FollowupID: 6298

Follow Up By: Member - Melissa - Thursday, Jan 16, 2003 at 18:20

Thursday, Jan 16, 2003 at 18:20
Thanks again Ozi. Looks like we've got some thinking to do. I just can't see the point of going to the trouble or expense to set up a DBS if the aux battery isn't up to the job. With so many GU's around, you'd think somebody has come up with a solution.

:o) Melissa
FollowupID: 6300

Follow Up By: Oziexplorer - Thursday, Jan 16, 2003 at 18:41

Thursday, Jan 16, 2003 at 18:41
Melissa if I get chance tomorrow or the next day or two to have a look at a GU Petrol Popper, I will see what the options are. Looks like there is a decent market to manufacture these battery trays. Even electro zinc plating them which is the cheapest form of metal finishing, and the few bits of angle and steel, a realistic selling price would be around $70 MAX.
FollowupID: 6305

Follow Up By: Tuco69 - Thursday, Jan 16, 2003 at 22:18

Thursday, Jan 16, 2003 at 22:18
Hi Ozzie and Melissa. Batteries - what a lovely subject!
Ozzie, you said "At the end of the day, the way we are using these auxilliary batteries in vehicles, no manufacturer to my knowledge will give you any more than a sixth month warranty, except Optima".

I have been using Cat batteries for over 20 years, and have generally had very good results. I will admit that I have had two failures, but Cat honoured their exelent warranty without question. They have a 2 year warranty with pro rata to 6 years. My previous vehicle - a 4x4 F150 was fitted with three Cat batteries - one under the bonnet and two in the tray for 2 Engels, Flojet pump, and HF radio. I still use 2 of those batteries, and both are over 4 years old.
Unfortunately my present Toyota Surf has only enough room for two N50's - so I am unable to fit the Cats. I will probably replace the cheap N50's that were in the vehicle when I purchased it - with Optima Yellow tops. The Optima will fit in where the N50's go.
I consider the Optima (expensive) as the only brand with quality to match the Caterpillar.

Link to Caterpillar batteries is at:

FollowupID: 6331

Follow Up By: Member - Melissa - Thursday, Jan 16, 2003 at 23:46

Thursday, Jan 16, 2003 at 23:46
Hi Tuco,

Can you clarify please...are you running 2 N50's as auxilaries or is one your main battery? If so, what sort of drawdown are you getting from the aux N50 with regard to running the Engel?

:o) Melissa
FollowupID: 6341

Follow Up By: Member - Melissa - Thursday, Jan 16, 2003 at 23:51

Thursday, Jan 16, 2003 at 23:51

I shopped around everywhere for aux. battery tray - 4WD outlets, auto shops, wreckers, internet etc. All quoted between $130-$140. Was lucky to get one 2nd hand (but brand new, never installed) for $60.

Every place admitted that the price was "out there" and apparently some trays for some makes/models are even more. I was told that they are Aust made and the company holds patents on all designs so they have the market tied up.

:o) Melissa
FollowupID: 6342

Follow Up By: Oziexplorer - Friday, Jan 17, 2003 at 07:48

Friday, Jan 17, 2003 at 07:48
Melissa just more typical lies of these 4WD outlets.
You could not patent a battery tray, and yes, you could register the design, but the costs of doing that would mean they would have to charge $1,000 for the trays. Yes, I realise they are Australian made, but that is just a disgusting lame excuse to rip you off. In most of these battery trays there is around $8.00 worth of steel (being generous), about $4.00 to passivate zinc it, and made on a batch production basis $12.00 for labour. 4WD stores are the new gold mines of Australia and are the worst rip-off lacking in proper product knowledge and advice places around. You can always buy products cheaper and often better value and design away from 4WD stores. Look at the Bushranger compressor $249, the Grunter from WA with the exact same power unit $75.00, from Supercheap 95% identical and the same power unit as the Bushranger and $99.00. Piranha battery isolator about $250 from 4WD outlet. Exactly the same device without wires and with terminals which are better around $100. Supercheap in October had a tow strap that was $34.95 - ARB identical strap $69.95
FollowupID: 6348

Follow Up By: Tuco69 - Friday, Jan 17, 2003 at 10:03

Friday, Jan 17, 2003 at 10:03
Hi Melissa, when you asked "Can you clarify please...are you running 2 N50's as auxilaries or is one your main battery? If so, what sort of drawdown are you getting from the aux N50 with regard to running the Engel? "

My 95 Toyota Hilux Surf has two N50's (410 cca each) fitted standard. Because of space limitations, Toyota has fitted two smaller batteries instead of one large one on many of their models. There is no isolation and the batteries are fitted in parallel. My vehicle wil start and run on either battery if I were to remove one. Cranking speed is reduced though.
When the batteries are due for replacement, I intend fitting 2 Optima yellow tops (650 cca each) and also an isolator. This is because with parallel batteries - if one fails, it will pull the other one down as well. Isolation is just a bit of insurance.

In my Surf I have an Evakool ED70 12 volt fridge that will cut out on the internal low volts after 2 days, if the engine is not run or charged from the 120 Watt Kyocera solar panel. With the roof mounted solar panel the batteries are always fully charged. Depending on temperature setting and also ambient temperature this usage time may change.


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Follow Up By: Oziexplorer - Friday, Jan 17, 2003 at 10:46

Friday, Jan 17, 2003 at 10:46
Melissa I may have found a proper deep cycle battery to suit your new battery try that is 75aH which would be quite acceptable.
Measurements are:
Length Width Height
255 170 220

Will this fit?
FollowupID: 6353

Follow Up By: Tuco69 - Friday, Jan 17, 2003 at 11:05

Friday, Jan 17, 2003 at 11:05
Mellisa, as a matter of interest, the Optima measurements are:
Length 254mm
Width 173mm
Height 199mm

which is much the same as Ozzie has found BUT 21mm shorter in height.

FollowupID: 6356

Follow Up By: Oziexplorer - Friday, Jan 17, 2003 at 12:08

Friday, Jan 17, 2003 at 12:08
Tuco but 20 amps less in capacity.
I find Optima batteries very hard to justify in cost.
Considering you can buy 5 ordinary batteries for the price.
As you can see, in this case they don't have the capacity for the size.
FollowupID: 6364

Follow Up By: Tuco69 - Friday, Jan 17, 2003 at 16:47

Friday, Jan 17, 2003 at 16:47
Hi Ozzie, Yes, but what is the point of having the extra capacity if the internal resistance of the battery won't let it charge fast enough from an alternator.
In my situation with solar putting a constant charge in daylight hours it is OK. But someone who will either use the vehicle alternator or the likes of a Christie alternator may find that unless they drive for a long time or run the generator for a long time - that the battery probably wont be charged to full capacity anyway.
As most of us rely on the vehicle alternator to replenish the battery, then in my view a battery with very low internal resistance is the way to go - despite the slightly smaller capacity.
I do agree that the Optima are way over the top when it comes to price though! I can buy 2 Cats for one Optima. But the Cats can take 4 to 6 hours at highway speed to fully recover, when the Optima will in 1 hour.

FollowupID: 6375

Follow Up By: Member - Melissa - Friday, Jan 17, 2003 at 17:15

Friday, Jan 17, 2003 at 17:15

Bad news...Just measured the tray and under bonnet "headroom" 243L x 19.4W x ~200H. Neither battery suggested will fit the tray. I'm starting the think the Exide is the only option in the short term.

:o( Melissa
FollowupID: 6376

Follow Up By: Oziexplorer - Friday, Jan 17, 2003 at 19:27

Friday, Jan 17, 2003 at 19:27
Melissa, I wonder if this has made the record at ExplorOz for the longest Response thread.
You probably got better service and advice here than what you could have paid for at a 4WD outlet. What is more, at least it was impartial and hopefully you found it informed and interesting.
FollowupID: 6381

Reply By: Steve Mc - Saturday, Jan 18, 2003 at 15:45

Saturday, Jan 18, 2003 at 15:45
Hi Melissa Try Pirahna for a battery tray that will hold a N70 battery same size as the starting battery, our 2.8 GU has limited space under the bonnet with a brake vacumn tank in the place where you would place the battery. Being a 4500 you might have the critter on gas this would account for no room & the problem you are having now. How did u get on with the dust problem hope we all solved the problem.

Cheers Steve
AnswerID: 11484

Follow Up By: Member - Melissa - Sunday, Jan 19, 2003 at 23:11

Sunday, Jan 19, 2003 at 23:11
Hi Steve,

Thanks for your info. We don't have gas or ABS. I have contacted TJM who are Pirahna stockists but they are still talking N50. However, we are starting to get to the bottom of things...

Found out on Sat that the "ARB" battery tray we have is in fact an Opposite Lock tray. I went back to our local ARB place and put it to them how they quoted us on a dual battery system inclusive of either a h/d or d/c battery when a decent battery won't fit in the tray. They had a look at our tray, made a call and confirmed that although the tray was sold by an ARB outlet, it is not THE ARB tray. Something to do with ARB stockists vs. ARB stores...didn't quite follow the explanation but we gathered that an ARB stockist doesn't necessarily sell only ARB endorsed products.

When we reminded the manager that his salesman (who quoted us) told us that the tray was so highly priced at $140 because there was only one supplier/manufacturer in Aust so no choice in trays, he was on the back foot. He stated that this is not correct (quite obvious to us now) and that the $140 was inclusive of the "conversion kit" that relocates the brake vaccuum. We said no, we were qoted an extra $40 for that. The manager then told us that there had been some "funny business" going on in his store and that a couple of staff members, including the one who quoted us were no longer employed. He could tell we were far from amused and "stated that he would look after us" when/if we booked the car in to have the DBS fitted. To be honest, we don't plan to have them do it as our confidence in them is about nil.

This is all making sense now as we couldn't understand why something better in the way of auxilary batteries wasn't available for such a popular vehicle as the GU's.

Anyway, at this stage no decision has been made. Our main battery is an N70 with 600 CCA. We have learned that we can get a N50 with 550 CCA that will fit the aux. tray so we are considering the viability of using the aux. as our main battery thus freeing up the N70 spot for a d/c battery. Don't know enough about vehicle electrics to know for sure if this is possible but hubby is going to talk to Nissan and auto electrician about it. With some of the newer petrol 4WD's like Prado and Disco's using N50's as main battery perhaps this idea has merit. We'll see...

Re: dust. We were away this weekend and had no dust problems running ac on fresh rather than circulate. Conditions weren't overly dusty but enough to give us some hope that our problem was solved. Also checked the back doors and found they do need a little adjustment -just haven't got to it yet.

Thanks again for your help Steve.

:o) Melissa

FollowupID: 6465

Reply By: Member - Nigel - Monday, Jan 20, 2003 at 00:20

Monday, Jan 20, 2003 at 00:20
Hi Melissa,

A suggestion that may solve your dilema.

You could get a AGM type battery (Exide Orbital or Optima) and put it in the small battery tray and use it for your starter battery, thus leaving your original N70 sized tray for a deep cycle. The AGM batteries have much higher CCA for their size, and both brands are over 600 CCA

I have a 95 Ah deep cycle and regularly get 48 hours of fridge run time without starting the vehicle, but I always recharge with a 3 stage program charger before and after trips. The deep cycle is over 12 months old now and still giving good run times.
AnswerID: 11548

Follow Up By: Member - Nigel - Monday, Jan 20, 2003 at 00:28

Monday, Jan 20, 2003 at 00:28
Doh - should have read all the responses first. I see you are already considering this option. Oh well you get that after driving 1200km in 2 days (with kids) :)
FollowupID: 6467

Follow Up By: Member - Melissa - Monday, Jan 20, 2003 at 01:14

Monday, Jan 20, 2003 at 01:14
No worries Nigel,

Your reply gives me some confidence that our idea does indeed have some merit.

BTW, I wouldn't trade your last 2 days for ours. Spent them camping on the beach north of Yanchep. Beautiful spot, good company...no wonder we all love this 4Wdriving/camping kind of thing. And our kidlet seems to be getting over his aversion to being in the car (touch wood).

:o) Melissa
FollowupID: 6470

Follow Up By: Member - Nigel - Monday, Jan 20, 2003 at 09:02

Monday, Jan 20, 2003 at 09:02
Forgot to mention the "BUT"....

if you run different battery types (ie one AGM and one flooded deep cycle) then they will all be much happier with an independant charge system like the Rotronics RFC12 or better. This will also have the benefit of much faster recharge of the deep cycle. I use this type of system even though both my batteries are flooded cells and find the aux recovery time is much shorter.

Yep kids can be fun in vehicles. When our eldest was about 2 we did a big trip and she had a bit of an aversion, but soon learnt that the time goes faster when she was playing or sleeping rather than screaming. Both our kids are now seasoned travellers but you still need more regular toilet stops with kids. We also make them go for a run when we stop.
FollowupID: 6479

Reply By: CHRIS - Friday, Jan 24, 2003 at 13:26

Friday, Jan 24, 2003 at 13:26
I have a 98 model GU patrol which has been fitted with a Piranah dual battery tray. The battery that I fitted was the large Odyssey ES12V1500. This required the end of the tray to be flattened and a new end stop to be welded on. The battery was then fitted on it's side with terminals facing towards the firewall. This allowed the bevelled edge of the top of the battery clearance on one of the aircon pipes. Also required repositioning of a clutch vacuum cylinderand some slight pipework modification. Battery has 77ah capacity and can be quickly charged. Fitted in parallel through a manually operated isolating switch with normal lead acid starting battery for this vehicle.
AnswerID: 11809

Follow Up By: Member - Melissa - Friday, Jan 24, 2003 at 13:38

Friday, Jan 24, 2003 at 13:38
Thanks Chris,

We've decided to fit an N50 in the aux. spot and then use this is the starter. This will free up the main N70 spot for a decent d/c battery to use as an aux. This is the simplest solution we can find. Apart from extending the starter battery leads, there is no moving of things required.
Our GU is a 4.5L petrol so an N50 will easily do the job as a starter.

Also, we usually tow an offroad campertrailer which is fitted with a d/c battery. Between the 3 we will be pretty well covered for a 4 or 5 night stopover which would be about our max. stop in any one place without giving the vehicle a good run in between.

Thanks again, Melissa

FollowupID: 6740

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