The 150 series Dual Battery Guide

[Isiman]

Wow, nothing like a bit of a debate :-)
I I think what I'll do is just get the sidewinder tray, which can't take a300mm battery, put a optima in it, and the 300mm M pro in the current starter battery position. I think that should keep me happy for a while.
The winch isn't in yet, not sure if I can convince the missus on putting it in, I'm kind banned from proper 4wding at the moment...
Thanks all for the input!

[LeighW]

Melbourne park,

The switch as you call it will link both batteries within seconds of the engine starting,
once they isolator links the batteries, each battery will draw what it wants from the alternator. As long as the alternator has sufficient reserve capacity it doesn't matter which position the batteries are in neither will affect the others charging.

Unless they have changed the marine pros the were a 100Ah, I constantly discharge mine to around the 40% mark, when I checked it a couple of weeks age was around 60Ah not bad for a 7 year old battery.

Cheers
Leigh

[MelbournePark]

My preferred choice for the aux battery would have been the one with the highest Ah.

Except that a starting battery you can only use 40% of its AH, a marine or hybrid/dual battery 60% of its AH, and a deep cycle 80%.

So if we look at the Marine Pro, with say 75AH, perhaps we will be able to access 45 AH. A similar 75AH deep cycle, then you'd plan on 60 AH, which is 33% more capacity than a marine or dual/hybrid's which has the same labelled Amp Hours.

If when working out your likely loads, everyone recommends being conservative, I think because if you push your batteries, they will not last nearly as long. Our problem with the Prado especially, is that we don't want to have too much weight up the front, yet it is weight that provides power in a lead acid box, so weight is good, but not for the Prado!

And there are different Prado users out there too - particularly I presume, those that have winches, compared to those that just are running I presume, lights and fridges. A winch requires lots of current, while lights and fridge usage is ideal for deep cycle batteries IMO.

For myself, there are some deep cycles around that can be put in a 4WD, and those are the ones that appeal to me. However, if one goes to a "cycling" AGM, the costs can be 75% more for the AGM. The benefits of AGM IMO seem only to be fast re-charging, presuming the deep cycle one is comparing it to is ruggedised (AGMs are inherently ruggedised). Curiously though, one distributor will not warrant its AGMs for under bonnet usage (in Australia that is). They say because of oil contamination!!

My preferred choice for the aux battery would have been the one with the highest Ah.

[MelbournePark]

I am not an expert, but have been reading up. So please correct my assumptions everybody. But be nice!!!

IMO the benefit of having the Optima as the starting battery, is that it has more CCA power, and also, it re-charges very quickly. So, if you are using both batteries for Auxiliary work, and the charge on the Optima drops to 50% of its amp hours, your device should ideally cut the power drain to the auxiliaries from the starting Optima battery. And then drain from the Marine Pro 730. When you start your motor, the starting battery should get the initial charge. Because the aGM Optima recharges very quickly, it won't take long for the switch to transfer the charge over to the secondary battery. And while that battery - the Marine Pro - takes long to charge, at least you have already charged the Optima. If it was the other way around, the Optima may never get its charge, because the Marine Pro takes longer to charge. Hence IMO Optima is best as the starting battery, if the electronics protect from starter depletion, and uses it for auxiliary power.

Incidentally, depending on your Optmax, the stats for two of the are:
24.1kg L309 W172 H219 140RC 66AH 830 D27F AGM Optima
19.5kg L254 W175 H198 120RC 55AH 750 D34 AGM Optima

So the Optima's don't have so much Amp Hours but lots of starting power. They also should tolerate many more re-charges than the Marine Pro, so that's another reason IMO to ensure they are used.

Strangely the web site for the Marine Pro lists the 730 weight as being the same as the smaller version. I therefore have increased its weight by my guesstimate, to 27kg:

27.0 kg L306 W171 H202 180 100AH 730 N70ZM WetM Century
24.1 kg L260 W171 H202 155 75AH 620 NS70M WetM Century

I guess the problem with the 730 Marine Pro is its weight and length, for in 150s you'd have to push the air con piping away from the battery. The issues of weight might be a concern to some 150 owners as well.

[Isiman]

Maybe I'm over thinking it, I could just use the marine pro as the starter, and do asyou say with the optima as the secondary.
Cheers

[Isiman]

At the moment all I have is the crappy original battery that was in the car, and no second tray. I also have a N70ZZL4WD and a marine pro 730 sitting on charge for when I get a tray. Obviously that combination won't work on a prado.
hence me thinking about getting something that will compliment what I already have.
Oh I also have all cabling and redarc sbi isolator to go in including a manual override switch (large, not in cab so that I can which through if needed). Cable is all 50mm welding cable with proper crimps.
Most of this has come out ofthe last car I owned, apart from the crap battery which came with the prado

[MelbournePark]

I already have a marine pro as well as the other n70 (which is unfortunately useless in the prado - not having enough space for 2x n70s) taken out of my Patrol before it left my hands - took all the good bits out before it 'went'. If I don't need to buy two new batteries then that is a good thing however when the Marine Pro does die, then I might consider getting a second yellow top.
I would be looking at using the yellow top as the starter and running accessories of the marine.
The marine pro is only about 4 months old.
I'll have a look at lunch time for the model of the charger.

Century AGM batteries are not warrantied in the engine bay. They claim something to do with their case!!! IMO there is the marketing department protecting their distribution of Optima batteries, which are also AGM batteries, but are warranted when used in the engine bay.

You have a Marine Pro and an Optima. Both have deep cycle capabilities. i am not sure which Optima you have, and which Marine Pro (there are several marine Pros). Curiously I recall the Marine Pro stats were incorrect with their weights, because two different versions had the same weight (I hate companies publishing incorrect data).

Anyhow, if you use the Optima as your auxiliary battery, the benefit in doing that, would be the Optima would re-charge a lot quicker than the Marine Pro can due to the Optima being AGM and also Optimas are know to re-charge quickly.

If you have a switch located for the batteries, then both batteries can provide auxiliarly power, but the switch will stop the starting battery from using too much of its capacity, which prevents a flattened start up battery. Such a device would also increases second battery life due to the second battery not being worked nearly as much.

If you have the Optima as the start battery and do not have its power connected for auxiliary service, you are IMO wasting the Optima's capabilities.

[Isiman]

Excellent, thanks for the advice!

[drivesafe]

Hi Isiman, if you set the charger to WET and 13.5, you can safely charge and maintain both battery types at the same time.

[Isiman]

The charger is a electro bc-1215.
I havethe following options
gel, wet, calcium
and 13.2, 13.5, 13.8

[Isiman]

I already have a marine pro as well as the other n70 (which is unfortunately useless in the prado - not having enough space for 2x n70s) taken out of my Patrol before it left my hands - took all the good bits out before it 'went'. If I don't need to buy two new batteries then that is a good thing however when the Marine Pro does die, then I might consider getting a second yellow top.
I would be looking at using the yellow top as the starter and running accessories of the marine.
The marine pro is only about 4 months old.
I'll have a look at lunch time for the model of the charger.

[drivesafe]

Hi Isiman and first off, why not just fit two Optima Yellowtop batteries.

This would give you two high current ( fast ) charging batteries, and you most certainly wouldn’t need a DC/DC charger.

Next, no need for pictures of your charge, just post up the make and model of your battery charger and we can Google for the manual for your specific charger.

[Isiman]

It's a N70ZZL4WD.

I will take a picture of my charger as it has 3x different battery types, and 3x different voltage settings on it - actually, no I wont as pictures on this forum seem to be really sucky (ie, they only display a link to the image). I will do it the old fashion way and type out what I see!

[MelbournePark]

ok, two quick questions:
due to the lack of space for 2x N70 sized batteries under the bonnet, would a Optima yellow top (as starter) and Century Marine Pro 730 (as secondary for fridge) need a DCDC charger such as the Redarc BCDC 1225 OR just use the diode trick and a basic sbi isolator?

Second question:
what type of batterys are the following (ie, wet cell/calcium etc)
Marine pro 730
'normal' century 4wd starter motor
optima yellow top

Thank you, sorry for ignorance

I will answer but no time at the moment.
Before i do can you also list the actual century battery model?