The 150 series Dual Battery Guide

[TuesdayMarky Lurker Find all posts View Profile Close TuesdayMarky]

Photos this time

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DT90 attached to top of fuse box. My one criticism of the Traxide unit is that the wire from the unit to the cranking battery is a bit short. If it was maybe 10cm longer I would have put the unit elsewhere. Although I could have lengthened that cable but didn't want to mess around too much.

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Dual battery/tray and relocated AC pipe bracket.

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Cig plugs in the back. The fuse block is located just under the cup holder, towards the rear seats.

mullerwh - I just got 14.2v at the cranking battery on a cold start at idle with the booster diode. However, all the testing I did before running the second battery fit within the parameters set by LeighW on his instructions. The cig plugs at the rear are reading 12.8v about 5mins after the engine is turned off.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

It's hard for anyone making up these units to guess how much cable each application will need. Cables are easily joined or as you have done relocate the unit a little. Sounds like it will work well.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

If you put a 25A charger in you'll lengthen you recharge times considerable when charging the
Optima's for a low SOC.

[Grumps189 Lurker Find all posts View Profile Close Grumps189]

Hi Marky, what's the go with the ARB tray and having to get someone else move the aircon pipe? I was sure I read elsewhere that the ARB tray is a straight fit and the aircon pipe just moves gently out of the way and re-attaches?
I'm about to do the same thing - and haven't yet chosen which tray to use. I too have the Traxide DT90 and am thinking of mounting it on the driver's side near the brake booster - stacks of room and solid - just need to run a substantial cable from the cranking battery. Don't like the idea of having something attached to the top of the fuse box - doesn't seem too secure to me.

Paul

[TuesdayMarky Lurker Find all posts View Profile Close TuesdayMarky]

Hi Grumps189,
I'd read the same about moving the air con pipe. I put the tray in first before sizing up a battery. When I tried putting the 85Ah battery that I ended up going with in there, the air con pipe was only just clearing it. I didn't feel great about the small gap nor moving it myself given some of the horror stories I'd read about the pipe breaking. Having said that I'm sure it would have been fine. But I went with the safer option and paid someone else (auto-elec mob in Darwin) to move it completely and fit a new bracket. It was only about $60 total for some peace of mind.

Nice work getting the DT90. Super simple to set up. I like your idea of putting it on the driver's side. I'm going to see how the top of the fuse box concept goes over the next while and may end up moving it and extending some cables.

Would be keen to hear how your set up goes!

[Bossy Lurker Find all posts View Profile Close Bossy]

Expensive setup

Can you tell me if a quote of $2500 is reasonable for dual battery setup including 2 anderson plugs in my Prado 150?

[brogers Advanced Member Find all posts View Profile Close brogers]

Can you tell me if a quote of $2500 is reasonable for dual battery setup including 2 anderson plugs in my Prado 150?

Impossible to comment without any details whatsoever. You will need to detail what you are getting for anyone to comment.
IF it includes an auxiliary deep cycle battery, a reasonable battery tray, some good quality 6AWG B&S cable from the main battery, and good quality 8AWG B&S cable to the anderson plugs, a couple of circuit breakers (or fuses), and maybe a DC/DC charger and or VSR, then it all starts to add up....and with someone doing the work...its probably best part of at least half a day or more labour....then you are likely to be getting close to $2,500 more than likely....but jeepers, (and not being rude) ,,,but how can anyone really comment without any details of your set up please "bossy"?

[mullerwh Member Find all posts View Profile Close mullerwh]

Not even close...unless in includes a big lithium battery and top of the range smart charger...but who needs that anyway !

[SimpleSi Member Find all posts View Profile Close SimpleSi]

Hi all. About to jump into a dual battery setup. Intention is to mount an Optima yellow top with VSR. (I have voltage booster). I currently have an anderson plug on the towbar which is fed from the start battery via a relay (only powered with ignition on).
I have a Camper Trailer with 200aH of batteries and I intend to add a Projecta IDC25 charger (in the CT).

Should I connect the towbar anderson plug to the Starter or Aux batteries? I'm thinking just leave it on the starter battery, problem is the anderson plug in the boot is also hooked in to it. Obviously I'd like the anderson in the boot on the aux battery to keep the beers cold. What is the downside to having the towbar anderson plug connected to the Aux battery?

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Why just take another feed off the VSR to the aux in the car and try the trailer without the DCDC chargerand see how you get on, as long as you run decent sized cable you should be able to charge the trailer batteries ok without the charger?

[SimpleSi Member Find all posts View Profile Close SimpleSi]

Why just take another feed off the VSR to the aux in the car and try the trailer without the DCDC chargerand see how you get on, as long as you run decent sized cable you should be able to charge the trailer batteries ok without the charger?

I have thought about this, but for the trailer, I'd like the option of 2 x unregulated solar panels, so it's either a decent MPPT controller or IDC25 ($150 vs $280?).
Perhaps I will just run the rear andersons (boot and towbar) off the Aux battery. I believe it is 6B&S all the way to the towbar. If I did it this way, I'd have to put a 2nd VSR in between the Aux battery and trailer batteries. (So once again a DCDC charger would do the job).

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

You just need to run a separate feed of the existing vsr for the cars aux. If you need to
isolate from the car then you can just disconnect the Anderson plug. Before I installed
my Lithiums that is what I used as all batteries had similar terminal voltages so just
left then connected to share the load, also had the advantage that when parked with
240V available the charger in the van would also charge the cars aux.

As for solar, if I was starting out from scratch I would purchase a good quality MPPT unit that can handle around four solar panels in series. Putting the panels in series gives the MPPT much
more head room to work with and you'll get a lot more current out in overcast conditions etc.

[SimpleSi Member Find all posts View Profile Close SimpleSi]

So my plan is (any suggestions appreciated):
Optima D27F $315
ARB Battery tray $120ish?
Kickass VSR $58 (Dual sensing and manual overide)
2-3m (Red) 6B&S to connect the battery +ve terminals (via VSR and 2 x 50Amp fuse/manual reset CB's?)
Solid Kits Dual voltmeter (Prado 150 switch). 6mm auto cable connected to each side of VSR through firewall. -ve connected to body under dash. $65
Disconnect the current 6B&S cable from the relay (not a vsr) and extend to the Aux battery +ve terminal.
Short 6B&S cable (Black) from Aux -ve to body.

Sounds about right? 50A or 100A Fuse or CB at each batterys +ve terminal?
6B&S do the job linking the batteries?

(Edit: I currently have a battery box in the boot running a 47L fridge (2degC). Drove a total of 45mins this morning and when I went to pick up kids at 3pm, the battery (fridge wasn't cycling) sitting at 12.9V. Leighs diode working well ;-)

[mullerwh Member Find all posts View Profile Close mullerwh]

Isolator vs BCDC charge times

Please correct me, having gone through the thread and trying put things into perspective, this is what I understand the difference to be between charging via Isolator and Redarc BCDC1225 in terms of time:

Battery 55AH Yellow Top Battery (max current input 40A)

Redarc output 25ah/h Time to charge to 90% of 55AH from 0% = 119 minutes
Isolator output 40ah/h (limited to battery input current) Time to charge to 90% of 55AH from 0% = 83 minutes

Difference in charging time to 90% = 36 minutes (isolator vs BDCD)

The time required to charge for the BCDC to charge the battery from 90% to 100% (additional 5.5Ah) is not known but is possible.
The isolator cannot charge the battery to 100%.

Taking a 50L Waeco CFX quoted consumption of 0.77ah/h the additional 5.5 AH (90%-100% of the battery) would provide for another 7.1 hours of running time.

Questions that remains:
Does higher voltage equals higher amperage output, if so does that mean 40a is not output at 13.6v, or does higher voltage only equate to less charging time?

Some serious assumptions above but comment would be appreciated.

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Hi mullerwh, if you have an Optima D34 ( 55Ah ) and it is at 10.5v ( 0% SoC ) a new Prado, with the lower operating voltage will get the battery back over 95% SoC in around 1 hour.

If you use your 25 amp DC/DC device, it will take over 2.5 hours.

In both cases, there is no reason why you can not get that last 5% of charge into the battery.

Even though it will take longer for an alternator to get that last 5%, it will still fully charge the Optima, but because your alternator can get the battery up over 95% much, MUCH sooner than any DC/DC device can, you will still end up with a fully charge battery in around the same time but for a lot less setup cost.

Something else to consider.

Say your Optima is flat but you only drive for an hour.

Your alternator will have your battery up over 95% in that time, giving you about 52Ah available for your next stop, but your 25 amp DC/DC device will only have replaced 25Ah at best.