The 150 series Dual Battery Guide

[Fred63 Advanced Member Find all posts View Profile Close Fred63]

Hi again Ghandi, try disconnecting the auxiliary battery, and you can do this by simply removing the NEGATIVE ( - ) terminal clap on the auxiliary battery.

Then connect the battery charge’s positive lead to the cranking battery’s POSITIVE ( + ) terminal.

Next, connect the battery charger’s negative lead to a good earth point in the engine bay.

Do not connect the battery charger’s negative lead to the cranking battery’s negative ( - ) terminal.

Even though the charger should be off, it is best to get into the habit of never connecting to the cranking battery’s negative ( - ) terminal for charging or jump starting, for safety reasons.

NOTE, you do not have to disconnect any of the cabling connected to the cranking battery, just charge it in place.

The higher RECOND voltage of 15.8v will not effect any of the vehicle’s electronics but also make sure the ignition is turned off AND THE KEY REMOVED.

You need to remove the key because quite a few vehicles now days, power up some circuit while the key is in the ignition but not turned on. Otherwise the charger will be trying to charge the battery and power any circuits that may be live.

hey might of missed something here...
Where do you put the ignition key if a 150???

[Piratepete Member Find all posts View Profile Close Piratepete]

Recently had some oil leaks fixed under warranty and in the process, Toyota dealer had to disconnect the AC plumbing. This caused a bit of a fault as when switched to AC, heating didn't work. Anyway, dealer was great and fixed it straight away, no charge but discovered something very interesting.

Noticed that I suddenly had a lot more clearance between the AC pipe and my battery than I had before. See my earlier post #418 for pictures and compare with today's photo. The AC pipe is now straight up and not bent. Heaps of clearance. Have they bent the pipe or fitted a new pipe? When I compare the before and after photos, there is definitely more clearance now. Whatever they've done I'm happy with it. And no, they haven't moved the ARB battery tray that the optima D34 is in.

[skips80 Lurker Find all posts View Profile Close skips80]

Hi All,

Just thought Id revisit this thread given that some of the info is now a couple of years old.

Ive been trying to see what dual battery everyone has been putting under their bonnets these days. Is there anything new on the market or are the yellow tops still getting the nod?

Ive been very happy with a 105ahr fullriver that Ive had for a number of years but it is both too heavy and too long to fit up front.

My choice will be paired with a redarc SBI12 which I have had for a number of years now. Simple setup running a 40 L Engel and a coupla LED lights with mainly weekend trips and maybe a 5 week trip on occasion with plenty of driving every few days.

Heading to the Perth 4WD show next week so will see what sales pitch wins me over unless I hear some convincing information on here.

cheers

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

You cant go wrong with a yellow top - and LeighW's booster diodes if you have the 3L.

You can use almost all of the 66AH and it'll take on the recharging as quickly as anything.

[2016 Prado GXL Lurker Find all posts View Profile Close 2016 Prado GXL]

Hi all.

We have just bought a brand new 150 Prado and need to put a dual battery in it for the fridge.

How has Toyota wired up the vehicle?

Is it that the two batteries are directly connected to form one large crank battery?

or

Do I need to put an isolator in for the second battery?

or

Do I need to put in a DC Charger (I have a Redarc BCDC 1240)?

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

1. Not usually
2. Yes
3. Maybe...

DCDC will do the job but it depends where you mount the battery and auxiliary. Plenty mount under the bonnet but the DCDC needs to be cool. A VSR will also do the job but be wary using these and dissimilar chemistry batteries (like AGM or lead crystal), not all work together nicely.

Read through this thread and the pre update thread. Decide if you battery is living under the bonnet or in the car (mine is inside). Then choose a battery. Then pick a charging device. Then wire up as per manufacturers recommendations.

Then run an adequately sized cable to the fridge location.

[Mick66 Lurker Find all posts View Profile Close Mick66]

The 150 series Dual Battery Guide

In the process of installing dual batteries in the V6, and after reading up on Pradopoint, did the usual voltage checks to find it too was charging low. Put in an order from LeighW and a couple of days later, with a Booster Diode doing its thing, alternator voltage output is now at a more satisfactory level. Happy as.

[TuesdayMarky Lurker Find all posts View Profile Close TuesdayMarky]

Hi all

Thanks for all the info in this thread! I've just put a second battery in my 2011 GX (3.0L diesel) and thought i'd post what i've done for those interested.

- Put in one of LeighW's booster diodes (worked as it should).
- ARB Battery tray.
- Got someone to move the air con pipe and put in a new bracket for it.
- Isolator from Drivesafe, the new DT90. I had one of his old isolators in a previous car and it worked well so I went with what i know. It's SUPER easy to install, even for a complete auto-electrical novice like me.
- Platinum series 85Ah battery (dual purpose, starting and deep cycle. It was a good price so I figured i'd give it a crack).
- I ran the cable from the DT90 into a fuse block hidden in the rear storage area which then runs into two cig plugs. There's a nice little space underneath the cup holder to hold the fuse block and store all the cabling.

All up took me the most part of a day to fit it but that was with plenty of procrastinating.
Initial circuit testing looks pretty good but yet to give it a proper test (ie. to keep the beer cold...) My needs are simple, to run a Waeco 50L fridge and a few lights and maybe a swag fan. The wet season in the North is really brutal...
Happy to receive constructive criticism from those who know better, as I said I'm a complete rookie! Can post photos if anyone's interested.

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

Nice work Marky, I doubt you'll have to much criticism on here as you appears to have done all your homework well! - the only thing you have forgotten is to post up some pictures of your handywork...

[mullerwh Member Find all posts View Profile Close mullerwh]

Nice work ! What voltage is you setup registering with the diode?

I went same route with a diode and isolator but have pulled the diode a few months ago. The voltage output seemed very high at times and was reading 14.6v every now and then. What is the ideal voltage charge level for charging the battery? Without the diode the vehicle is now charging minimum at voltage of 13.6 with the diode is sitting at 14.2-14.4v. (2010 GXl Diesel)

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

mullerwh,

When were you seeing 14.6V?

[mullerwh Member Find all posts View Profile Close mullerwh]

mullerwh,

When were you seeing 14.6V?

It would go up to 14.6v when I start the vehicle and drop after about 10min or so down to 14.2-3v

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

Yep that is fine, no problem as it only there for a few minutes.

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

Hi mullerwh, any variable or constant voltage up to 14.7v is fine for charging any type of lead acid battery.

NOTE, a continuos voltage of 14.7 from a battery charger is to high, because it can be on for day or weeks at a time and this is why Battery chargers, solar regulator and decent DC/DC devices have a float mode, where the voltage is lowered once the battery is fully charged.

This is not necessary when charging from an alternator because no one drives long enough for the higher voltage to cause any problems. And a number of new vehicles actually run at 14.7v when ever possible.

[mullerwh Member Find all posts View Profile Close mullerwh]

Thanks for the help guys. I have a Redarc BCDC1225 sitting in the garage and have been tossing up whether to install it or not but the current isolator setup has been working well the last two years. I'm running a yellow(2nd) and red(main) top optima battery.