My dual battery installation

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

The D34R is perfect for a cranking battery (800CCA) and it's a nice price as well. I was going to get the Yellow Top D34 because of its Deep cycle abilities in addition to cranking ( the red top are cranking only) and that's fine if you've got a dual batt system, but if for some reason, your main batt is run dead flat, at least if you've got either a yellow or blue top you know your battery is recoverable. In the end I put in a D27M. mainly because I got it through a friend who works for a distributor at a ridiculous price. And because I dont presently have a dual batt system, I have the security in knowing that I've got a battery that packs some punch that I can safely run some accesories of it for a short period of time (a day or so without charging). Hope this helps...

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

Hi 1coolbanana, the chart is for “loaded” voltage readings.

There are two tables used for determining battery State of Charge using a voltage reading. One is for OPEN CIRCUIT voltage readings and the other is for loaded voltage readings and there is lots of confusion about which one to use.

The problem is compounded when self-proclaimed auto electrical experts continually use the wrong table.

OPEN CIRCUIT tables are meant for reading battery State of Charge voltages in RAPS ( Remote Area Power Supplies ) and UPS ( Uninterruptible Power Supplies ) as found in things like communication backup power supplies, where batteries site in an unused state for weeks and even months at a time, but these OPEN CIRCUIT tables are of no use in automotive and RV applications, where batteries are in continual charge/discharged cycles.

To get a reasonably reliable OPEN CIRCUIT reading, the batteries must not be charged or discharged for at least 24 hours, so you can see how useless OPEN CIRCUIT tables are for our requirements.

The chart I posted is a standard loaded voltage table and can be found in a number of place. The table is still only accurate while the batteries are being discharged with a small load.

This brings the credible use of these volt meters into question. The only time you can get a rough instant reading of any real use is when the battery has been in use for a while with a relatively light load, like a small compressor fridge and/or some camp lights.

In this situation, you can get an instantaneous indication of whether your battery(s) are still high or getting lower or are in need of a charge and more realistically, whether you have a day or twos worth of capacity available or whether your battery(s) is going to go flat over night.

Using a volt meter while the motor is running is useless because you are only going to get alternator voltages and once you do stop, it will still take a few hours of use to “Burn off” the surplus voltage that all batteries carry just after being charged.

There is lot more to getting good info about your batteries and there is no cheap way to get an accurate indication of the State of Charge of lead acid batteries so save your money.

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

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!

www.autocraft.au.com They are selling them for $380 plus $40 postage to Darwin or $50 postage for two. So you being in NSW I'm tipping it would be cheaper. They are in Tas.
Here is the link for batteries http://www.autocraft.au.com/optima/index.html

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

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

Cheers

D34R (Not warranted for deep cycle applications)
CCA 800
50AH
$315

D27F (Can be used for both cranking and deepcycle)
830CCA
65AH
$380

So looking at the above specs D27F is better... But more expensive. If its only for cranking then yes D34R is better as the Prado only needs about 710CCA.

http://www.optimabatteries.com.au

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

BTW, D34R CCA 800 & "50AH" (typo by winniliss)

fixed, cheers

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

Completed my dual battery install http://www.pradopoint.com/showthread...o-GXL-TD/page2

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

Anybody using these?
Allrounder MRV70L, specs seem quite good.
They are on special, delivered $209.
I know its no Optima D27F but will it do a good job for cranking and winch duties at half the price?

http://www.onlinebatteries.com.au/al...70l-p-463.html

[Trekrider Banned Find all posts View Profile Close Trekrider]

Anybody using these?
Allrounder MRV70L, specs seem quite good.
They are on special, delivered $209.
I know its no Optima D27F but will it do a good job for cranking and winch duties at half the price?

http://www.onlinebatteries.com.au/al...70l-p-463.html

That's the one I have as my second battery. Seems pretty good but as you know, although my winch is connected to it, I haven't used it in anger yet.

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

I will want to use this as my one and only front battery for cranking and winching (when I decide on one )

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

Anybody using these?
Allrounder MRV70L, specs seem quite good.
They are on special, delivered $209.
I know its no Optima D27F but will it do a good job for cranking and winch duties at half the price?

http://www.onlinebatteries.com.au/al...70l-p-463.html

I've got one of these mounted on the ARB 2nd batt tray...1 year on no problems at all, ran the fridge for 2 days and didn't kill it

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

Thanks.

Bugger, wrong thread, I meant to put the question in another thread!

[RocknRolla Lurker Find all posts View Profile Close RocknRolla]

Hey Chippy, are you still offering help on a dual battery system for any pointers in perth??
I am in Hammy Hill and looking into fitting a new Dual Battery rig to my 2004 V6 120 Pertrol/LPG I just purchased.
Would love to look at your setup and see whats what.
And we could blow the foam of a few on me if you've got any spare time.
Cheers!