My dual battery installation

[craigm Addicted PP Member Find all posts View Profile Close craigm]

Got a reply from Optima batteries who suggested the D27 for the Aux. I am just confirming if he means the D27M Blue top and also if its ok to be charged using a Redarc BCDC1240

The characteristics of the D27(F) & D27(M) are the same. The only difference is in the D27M is the additional terminal posts for accessoy cabling, and the poles are different (D27F is Positive Right, D27M is positive left)

Craig

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

I am drafting up parts to use and ways to install a dual battery system. So far I have come up with the following, starting from the alternator:

1. Installed a diode to increase alternator voltage output. Output varies between 13.7 and 14.1vdc

2. Replace main battery with an Optima Yellow Top D27F AGM battery ($380plus p/h autocraft – do google search for battery)

3. Run 2G / 35mm2 160amp cable ($14.50p/m – Jaycar example) from main battery to the Aux battery via a Redarc SBI12 isolator ($89 Ebay). Use a momentary switch with the SBI12 which allows me to use the Aux battery to assist in jump-starting and or winching if required. Isolator will be mounted next to the main battery (as advised by Redarc). Cable will be routed along the radiator to keep it short.

4. Install a Piranha dual battery tray behind the driver’s side headlight.$170 approx

5. Aux battery to be the same as the main battery

6. Install a Redarc BCDC1240 DC – DC charger ($475 Ebay) to charge the Aux battery. The BCDC1240 allows me to connect an unregulated solar panel. Looking at 120 to 180watt system.

7. Install a battery monitor. I am looking at ABR sidewinders but his uses negative switching for the battery isolator. I found this other one that uses positive switching:
http://www.ebay.com.au/itm/Dual-Batt...item2a1334165a

8. There are two thoughts on either to crimp or solder or both, the lugs onto the cable. There is also another thought to tin the wire then crimp the lug onto it…What are peoples thoughts on this.

9. What are people’s thoughts on fuses between the main and Aux batteries. Keeping in mind I wish to use it for cranking / winching. If it has to be fused I am looking at 200amp circuit breakers on Ebay.

10. Will be buying a hex crimper $125 Ebay (other places wanted $400)

http://www.ebay.com.au/itm/Battery-Cable-Lug-Crimp-Tool-10-120mm2-HEAVY-DUTY-/330543892821?pt=AU_Car_Parts_Accessories&hash=item 4cf5f38955

11. Looking at a smaller ratchet crimping tool- p/n 56512 Narva website for the smaller cables. What are people’s thought’s.

http://www.narva.com.au/products/browse/tools

12. Will be using corrugated tubing and dual wall (resin)heat-shrink for the cables etc

13. Battery terminals, looking at 2 types:

http://www.ebay.com.au/itm/4-Wire-Gold-Battery-Terminal-2G-4G-2x8G-Negative-/280700892548?pt=AU_Car_Parts_Accessories&hash=item 415b13b584or

http://www.ebay.com.au/itm/DUAL-BATTERY-SYSTEM-TERMINALS-HEAVY-DUTY-FORGED-BRASS-/310340285393?pt=AU_Car_Parts_Accessories&hash=item 4841b8f3d1

Have people got other suggestions?

That’s about it. I think I have covered everything.

The batteries will be Optima D27F.
Speaking to Battery World today, they stated that a relay would be better than a solinod because they have less voltage drop. For example http://www.matson.com.au/sales/Batte...ay_140Amp_12V/
They have a switched version to run the batteries in parallel or I could just use my jumper cables if required.

The batteries will have to be heat shielded due to high temperatures we have in Darwin. As a result a DC-DC charger won't be appropriate as advised be Battery World and the charging battery specs. http://www.optimabatteries.com.au/Co...0YellowTop.pdf

[sandman Member Find all posts View Profile Close sandman]

I've had a look at the Battery Specs and they seem to fall into the Redarc dc-dc charger range. Also I've just mounted my bcdc1220 under the bonnet of the Prado, again after chatting to Redarc directly the consensus is to make sure wherever its mounted its not near the exhaust manifold and it has airflow. I'm up in the Alice and it gets stinking hot up here, as long as there is air flowing across it, the unit should be fine.

Solder v's crimp, I bought a nice ratchet crimp tool that manages 8B&S lugs/cable. Just tonight I crimped the wire into the lugs and ALSO poured solder into the joint. Some heatshrink and 10mm corrugated split conduit over it and we're away (Supercheap). Install looks real nice.

I'm not cranking or winching, I decided to get the Maxi fuses (inline with 8B&S cable) and crimp lugs. I would have liked breakers but everything I saw on fleabay looked a little cheap or bulky. The panel mount breakers had little rubber hoods that i thought were a little amateurish, the larger breakers looked nice but again a little harder to mount. One thing you definitely want (as you already know living in the Territory), it needs to take corrugated roads.

Good luck, you definitely seem on the right track. Only thought is if you're planning to pull over 100A out of the 2nd battery, I'd probably run an earth cable between the batteries and not just use the car body as the earth. Maybe get a 2nd opinion from a Car Sparky. The redarc bcdc1220 I think pulls a max of 20A or so from the main so I'm ok to use the car chassis as a conductor.....winching is a totally different story, lots of current :-)

Best of luck !

Pete

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

Hi winniliss and the following are just some suggestions

1. Installed a diode to increase alternator voltage output. Output varies between 13.7 and 14.1vdc

This is probably the single most Advantageous improvement you can do as it will not only allow much quicker charging of your batteries, it will also improve your headlights and LeighW on this forum, is the best guy to get the booster from.

2. Replace main battery with an Optima Yellow Top D27F AGM battery ($380plus p/h autocraft – do google search for battery)

This really only needs to be done if your current cranking battery is on it’s way out, otherwise, use it till it does need replacing.

3. Run 2G / 35mm2 160amp cable ($14.50p/m – Jaycar example) from main battery to the Aux battery via a Redarc SBI12 isolator ($89 Ebay). Use a momentary switch with the SBI12 which allows me to use the Aux battery to assist in jump-starting and or winching if required. Isolator will be mounted next to the main battery (as advised by Redarc). Cable will be routed along the radiator to keep it short.

If you need to join batteries during winching then you need a a higher current rated isolator. If you only plan on jump starting then that Redarc isolator is fine and you can also drop the size of the cable to 6B&S ( 13.5mm2 ) and again if you are not winching, I would also recommend you run the cable around the back of the engine bay.

One more point here, I wouldn’t put too much faith in what your battery seller told you. Solenoids and relays are the same thing, relays are usually just smaller versions of a solenoid and another warning, if your Redarc plays up, it’s repairable, while the isolator you have in your later post is a sealed type which means it’s a throw-away once the warranty expires.

4. Install a Piranha dual battery tray behind the driver’s side headlight.$170 approx

As per your requirements.

5. Aux battery to be the same as the main battery

As above, you really only need to do this once your existing cranking battery dies but the Optima batteries are the way to go, if you don’t mind the cost, both for use while winching and because they can safely be quickly recharged with high currents, and this again makes the voltage boost diode an advantage.

6. Install a Redarc BCDC1240 DC – DC charger ($475 Ebay) to charge the Aux battery. The BCDC1240 allows me to connect an unregulated solar panel. Looking at 120 to 180watt system.

Again, if you fit the voltage Boost Diode, then this device will actually be a waste of money if you go with Optima batteries.

7. Install a battery monitor. I am looking at ABR sidewinders but his uses negative switching for the battery isolator. I found this other one that uses positive switching:

With one usage exception, these are a waste of time and money, and I mean any form of voltage monitor,not just this one. They are useful, while camping, to keep an eye on your auxiliary battery but are usually mounted is a place that means you have to enter the vehicle to use them. A $10 digital multi meter is a better option and can be use for a host of other chores.

The reason in-cab battery monitors are a waste of time is because once your motor is started, the only voltage you will read is your alternator’s voltage. Once you stop, unless you have a load on the auxiliary battery, the only voltage you will read is the surface voltage and even with a stuffed battery, you can still get a reading that would indicate the battery is fully charged.

8. There are two thoughts on either to crimp or solder or both, the lugs onto the cable. There is also another thought to tin the wire then crimp the lug onto it…What are peoples thoughts on this.

This one always generates debate as to which is best. The facts are that they both give very similar results but there are pros and cons for both.

If you don’t have the correct crimping tool, it’s an expensive purchase just to do a few terminals, and it’s, as recommended in another reply below, easier to get them fitted by an auto electrician or the likes, for a minimal charge, but even if you do buy a crimping tool, you need to use it correctly or you can easily stuff the terminals.

Soldering actually gives a stronger joint and this is documented by a number of testing laboratories, but the difference is minimal. You do need a large soldering iron but these are heaps cheaper than decent crimping tools. In my opinion, soldering is also better for novices because if they get it wrong, they can heat, remove and solder again. You can't do that if you stuff a crimp joint.

As for wicking, so what, it means nothing, it will NOT make a joint more susceptible to fatigue, not securing the cable properly in the first place is what causes fatigue, no matter what type of joining method you use.

9. What are people’s thoughts on fuses between the main and Aux batteries. Keeping in mind I wish to use it for cranking / winching. If it has to be fused I am looking at 200amp circuit breakers on Ebay.

If you are going to be winching, using the second battery, then there should be no fuse or circuit breaker in the cabling between the two batteries.

If you are only intending to jump start then 50 amp auto resetting circuit breakers will allow you to do that but still protect the cable.

10. Will be buying a hex crimper $125 Ebay (other places wanted $400)

As above.

11. Looking at a smaller ratchet crimping tool- p/n 56512 Narva website for the smaller cables. What are people’s thought’s.

Again, as above

12. Will be using corrugated tubing and dual wall (resin)heat-shrink for the cables etc

As per your requirements.

13. Battery terminals, looking at 2 types:

Have a look at the battery terminal clamps in Trekrider’s second photo. These are by far the most versatile type to use. I sell both these and the larger types, and while I can make more profit selling the bigger terminal clamps you are looking at, I always recommend the smaller, ( and cheaper ) clamps like Trekriders.

These clamps can be used to give you both permanent fixed cables and easily fitted and removed cable connection in one set up.

To do this, you can take the wing nut off, remove the bolt from the under side, fit what ever cables are likely to be needed as a permanent connection, like your starter motor and alternator cables, and then secure the bolt back in place.

You can then fix and or remove other cables as required, by use of the wing nuts, with out interfering with the main cables.


Again, these are just suggestions.

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

G'Day Drivesafe,

The diode I did myself.

I will replace the main battery (when it dies) with a D27F. The battery is 2years old so couple more years would be nice.

I might just run 6B&S from main to aux via the isolator (that way I canget a roll of it and run power to the rear of the vehicle etc) and for winchingand jump starting run my jump starting cables from aux to main battery.

I will be giving the DC-DC charger a miss for the time being.

The battery monitor will have to be external and I could get a simple voltmeter and attach it to the fridge unless the Engel fridge already has one. Just so I know if the battery goes down to about 10 volts. Thats about 50% of the battery capacity?

I am not going to worry about a fuse between the main and Aux batteries.

The crimper's I will still get as I have a few other jobs that need doing i.e. my boat etc.

You wouldn't happen to know what size cable Toyota uses between the alternator and the main battery. I'm tipping it's rated to 120amps (match the output of the alternator of a 2009 D4D).

Been shopping around and the best price on an Optima D27F. $380 +$25 p/h to Darwin http://www.autocraft.au.com/index.html

[craigm Addicted PP Member Find all posts View Profile Close craigm]

Mate i don't know about the 150 but I extended the cables on a mates 120 D4D last week and I was blown away by the size of the cable from the Alt. (or from down that way, there a 2 +ves, 1 from to the loom that heads off to the alternator and 1 from the fuse box.) This cable is almost twice the size of my 04 petrol grande.

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

[SIZE=3]The battery monitor will have to be external and I could get a simple voltmeter and attach it to the fridge unless the Engel fridge already has one. Just so I know if the battery goes down to about 10 volts. Thats about 50% of the battery capacity?

Hi again winniliss, 10v would be a dead flat battery, the chart below will help you.

Cheers.

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

Well...

Cheers for that.

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

Finalised my choice and price for my Aux battery. Optima D27F for $420 including postage to Darwin.
Just need to source my Piranha battery tray. Any ideas of places to buy from for a good price?

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

Mate i don't know about the 150 but I extended the cables on a mates 120 D4D last week and I was blown away by the size of the cable from the Alt. (or from down that way, there a 2 +ves, 1 from to the loom that heads off to the alternator and 1 from the fuse box.) This cable is almost twice the size of my 04 petrol grande.

Do you know what size?

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

Finalised my choice and price for my Aux battery. Optima D27F for $420 including postage to Darwin.
Just need to source my Piranha battery tray. Any ideas of places to buy from for a good price?

Piranha battery tray from TJM $155

[craigm Addicted PP Member Find all posts View Profile Close craigm]

Have a look at www.batteriesdirect.com.au they seem to be pretty competitive...

[1coolbanana Avid PP Poster! Find all posts View Profile Close 1coolbanana]

Anywhere in Sydney you guys might recommend to get an Optima D27F?
I want this to replace my main battery as I have 2 batteries in the rear (of the car )
The local auto elec whos very good, cant get one for me from his suppliers.
The local Battery World wants $555 and on special fo $500!

[1coolbanana Avid PP Poster! Find all posts View Profile Close 1coolbanana]

Have a look at www.batteriesdirect.com.au they seem to be pretty competitive...

Thanks mate.
Im nearly tempted to go a D34R as my main cranking battery.
Any reasons to not go the D34R?

Cheers

[1coolbanana Avid PP Poster! Find all posts View Profile Close 1coolbanana]

Hi again winniliss, 10v would be a dead flat battery, the chart below will help you.

Cheers.

Are these stabilised voltages or under load?