[zoukshin]

Ok - I had assumed that falcon CL (or something like that) alternator swap was a good mod to crank out more amps.
I'm happy to keep going with the factory one then

The redarc has the override switch function as well, from what I have read, in case you want to crank from the second batt. Could be useful at times.
Might hit some wreckers to find some suitable copper for cheap, then go the 90$ ebay redarc.

Bonus question, can anyone with an d34 optima confirm they are 199 mm tall (without terminals) ? My sca tray is only 190 wide, so looks like some hammering is in order.

Cheers all, I appreciate your answers !

[zoukshin]

It's just for a fridge. fine by me I reckon. Chop and b4t seem to use a d34 yellow top too.
[edit]And Sco-tie as well viewtopic.php?f=4&t=32109&hilit=optima+d34&start=60

Also thanks for that PDF, It said what I wanted to know: 199.21 mm (Height at the top of terminals) which means it should fit just fine in the tray without bashing it

[johnmath]

Supercrap $80 on special - works well.

[zoukshin]

ah so the projecta has an override switch that's not wired in the dash ? os is there a pin for that in parallel ?

[johnmath]

zoukshin wrote:

ah so the projecta has an override switch that's not wired in the dash ? os is there a pin for that in parallel ?

For the odd occasion I might have a flat starter battery, I can lift the bonnet and press the button. It's still less work than jumper leads.

ozinflames wrote:

iv tried the projecta's and had 2 fail we get a pretty regular flow of them being replaced under warranty.

Some people can just be lucky / unlucky, I guess. I half expected trouble from SuperCrap, but other more reputable companies sell them as well, including Repco.
The beauty of SuperCrap is being able to put a watch on an item and getting an email when it goes on sale. That's how I got mine so cheap, about $50 off the regular price.
Plenty of people on other 4WD forums have had good experience with the unit, which was another reason I chose it. YMMV.

http://www.projecta.com.au/site/Default ... Issue1.pdf

[ZUZUKI]

A bit reluctant to suggest a simple silver can solenoid on a 2004 car - sort of 'get away with it' on a carbied Sierra, but computers might get sick of the surges.
Redarc are very common, do the job for most people - is a solenoid with some smarts about it.
Better again is a Piranha DBE140S - relays to switch the power, fully sealed, priority charge cranking batt, clever bit of kit.
Cost $165 + cable kit if you want it - 3m is $85.
Yes, I work at Piranha, & see some really horrible set ups in cars......
10mm2 cable to link the batteries, 6mm2 cable to the socket/s. Jumper lead between the Pos terminals (leave earths connected to the engine / chassis) if you need to jump start.

[fordem]

I just want to point this out - a solenoid switch is a relay by another name - works exactly the same way - low current through a coil creates an electromagnetic field, attracts an armature, closes a contact. An arc and a surge are going to occur any time there is enough of a potential difference across the contacts to cause a high current flow.

Let me make it clear - I'm not discussing the smarts of your product, I'm challenging your pointing out that "computers might get sick of the surges" - what does your Piranha do to minimize surges that either the Redarc doesn't, or for that matter a savvy user with a knife switch couldn't do?

[ZUZUKI]

I agree the basic principal is the same. The silver can solenoids are a fairly blunt device and not overly well sealed - condensation & corrosion builds up on the disc that transmits the major power load.
The redarc, although still solenoid based, is better in this regard (we don't sell it, although do use their BC/DC chargers & remote dial type brake controllers)
Royce listed the drawbacks to a purely ignition switched device.
Units that 'Voltage sense', or priority charge the cranking batt, allows for the car to be running & the cranking batt to recover a bit & stabilize the voltage, before introducing the draw that a lower charged aux. battery takes out of the alternator.
A relay can also suffer degraded contact over time, but are longer lasting and 'softer' in the switch of power flow than a solenoid.
The Piranha units are computerised themselves & monitor a variety of factors, to the point they will isolate charge to the aux. battery if problems are detected, rather than 'blindly' pumping in voltage.
Current flow is limited to the direction of cranking to aux. only so a more charged aux. doesn't 'feed back' into the cranking.
These sorts of 'levels of refinement / sophistication' in the management of aux. batt. charging are much kinder to ecu's than older styles of dealing with the potential difference in charge between main & aux. batteries.
But hey, I see plenty of ecu equipped cars still running straight solenoids or variations on that theme, & seem to be ok, but just saying that the potential for ecu harm is greater & they aren't recommended.
Michael V.

[zoukshin]

ZUZUKI, thanks for sharing that info,
If anything it's worth a look to compare and make up one's mind.

[Zookrider]

I just used an old winch solenoid out of my warn.
I run 2 optima batts without dramas.
I activate it off a DPDT Narva sealed switch. So mostly it comes on with the ignition, but can override from the Aux. I have 2 little 7seg volt meters (fleabay) that show me how they are going when the the link is off.
So almost cost me nothing and is bomb proof.