Dual Batteries in about an hour

[Dace]

so if you have a winch and are pulling out heavy stuck nissan it drains both batteries

In that situation, ya need a flux capacitor.

[Moriarty]

so if you have a winch and are pulling out heavy stuck nissan it drains both batteries

In that situation, ya need a flux capacitor.

Write to the US SG team and see if they have a spare ZPM.

These have huge power reserves and last for ages and ages.

[Cloggy_NZ]

My understanding of the isolation relay is they close the contacts when they sence 13.x volts which is the alternator output, this means the 2 batteries are isolated from each other when the engines not runing and they are connected together in paralell via the relay when the engines running and the alternators charging.

Yup, which is fine if you want to use the second battery for running a fridge all day and all night and still want to be able to start the car. But when my Land Rover is stuck to the door handles in water with the engine dead, I will want both batteries to provide everything they have got to get me out of that predicament. I definitely don't want them isolated then.
So I guess that answers the question about the isolation relay. Don't need one of them.
But when back on dry land and the engine started again, there would surely be an advantage to get one battery fully charged before the second one. Logic has it you can charge one battery in half the time you can charge two batteries. One fully charged battery is better for starting the truck than two running in parallel and only half charged?
So do we need some sort of voltage sensing relay which isolates the batteries only during charging?

[Jerry]

perhaps you have a "warp 10" switch which switches it from fridge/starter mode to drain both batteries dry mode, coupld do this maybe with a 2nd circut and then you switch between them.....

[Cloggy_NZ]

Yep, perhaps something like that.
Even the fancy 4wdsystems isolaters kiwipete put the links up for a couple of posts up only seem to let the winch run on only one battery. Unless I am reading it all wrong

[Jerry]

Run it in parallel then for now...do you want to have a look at my prado wiring?

[wjw]

Have a voltage sensitive isolation relay and a big arse switch wired in parallel, so you can bypass the isolator when you want to that would work...

[Smurf]

http://www.projecta.com.au/cataloguepages/asset_id/9/

available from Repco or local auto sparky.
I have the electronic isolator in my surf.
It also has a button which joins both batteries together for a self contained jump start if needed or for winching etc

[Moriarty]

My understanding of the isolation relay is they close the contacts when they sence 13.x volts which is the alternator output, this means the 2 batteries are isolated from each other when the engines not runing and they are connected together in paralell via the relay when the engines running and the alternators charging.

Land Rover is stuck to the door handles in water with the engine dead, I will want both batteries to provide everything they have got to get me out of that predicament. I definitely don't want them isolated then.
So I guess that answers the question about the isolation relay. Don't need one of them.
But when back on dry land and the engine started again, there would surely be an advantage to get one battery fully charged before the second one. Logic has it you can charge one battery in half the time you can charge two batteries. One fully charged battery is better for starting the truck than two running in parallel and only half charged?
So do we need some sort of voltage sensing relay which isolates the batteries only during charging?

NOPE!! you have a big-arsed Alternator that will happily supply 140 amps. splitting this in half, you got approx 70 amps feeding each battery, assuming you have 'em in parallel. Whyfore you want more than that? you wanta see how hot your batteries can get? Seriously, the faster you charge em, the faster you convert the battery acid to water, hydrogen and lead sulphates. (if memory serves me right)

IF you want to have a fridge battery, leave your two service batteries in fixed parallel, and put a third in current sensitive isolation for the fridge.

[Jerry]

I can't wait to see him up to his door handles in mud

[Red90]

I was thinking alnog the lines of something like this

http://www.traxide.com.au/trax1sc80_2.html

What do you folks think?

[Moriarty]

I was thinking alnog the lines of something like this

http://www.traxide.com.au/trax1sc80_2.html

What do you folks think?

Best idea yet, for installation and flexibility.
One MAJOR drawback, it's limited to a max of 80 amps. Most modern alternators can produce 140 amps. so for winching operations, only the third option is practicable.

Note my post earlier, with the 140 amp CS-relay

[wjw]

Also my winch based on the spec sheet draws 450Amps at stall

[Red90]

Best idea yet, for installation and flexibility.
One MAJOR drawback, it's limited to a max of 80 amps. Most modern alternators can produce 140 amps. so for winching operations, only the third option is practicable.

Note my post earlier, with the 140 amp CS-relay

Took your advice, picking up one of these relays tomorrow, around $120 so I'm told.

[scs]

I can see one problem with this setup. lets say you have computer controlled injection, you turn your truck off and run your isolated battery so stupidly flat, it cant supply any power at all. Now when you come to start the truck, yes the motor turns over, but the isolated battery has no power to trigger the ignition, ecu, fuel pump etc. ne way I can see away around this is maybe having a secondary switched wire between the 2 batteries, bypassing and isolater switch and if you run the acc battery flat, you can flick this over and power up the ecu and fuel pump. alternatively you can run the ecu ignition etc directly off the starting battery through relays.

[Smurf]

I can see one problem with this setup. lets say you have computer controlled injection, you turn your truck off and run your isolated battery so stupidly flat, it cant supply any power at all. Now when you come to start the truck, yes the motor turns over, but the isolated battery has no power to trigger the ignition, ecu, fuel pump etc. ne way I can see away around this is maybe having a secondary switched wire between the 2 batteries, bypassing and isolater switch and if you run the acc battery flat, you can flick this over and power up the ecu and fuel pump. alternatively you can run the ecu ignition etc directly off the starting battery through relays.

Easy, fit one of these,
http://www.projecta.com.au/catalogue/cid/23/asset_id/53
I have one and all you need to do is pop the bonnet, push a button and jump start yourself, easy as.

[Moriarty]

I can see one problem with this setup. lets say you have computer controlled injection, you turn your truck off and run your isolated battery so stupidly flat, it cant supply any power at all. Now when you come to start the truck, yes the motor turns over, but the isolated battery has no power to trigger the ignition, ecu, fuel pump etc. ne way I can see away around this is maybe having a secondary switched wire between the 2 batteries, bypassing and isolater switch and if you run the acc battery flat, you can flick this over and power up the ecu and fuel pump. alternatively you can run the ecu ignition etc directly off the starting battery through relays.

The whole point of the exercise, is so you DONT run your SERVICE battery flat, only the Aux battery.

That what my setup does anyway.

[scs]

just saying if you set it up wrong and your engine electronics rely on the aux batt while the starting batt is isolated and youve flattened it, it wont work.

[Sadam_Husain]

just saying if you set it up wrong and your engine electronics rely on the aux batt while the starting batt is isolated and youve flattened it, it wont work.

That would definately be set up wrong

[wjw]

The whole point of the exercise, is so you DONT run your SERVICE battery flat, only the Aux battery.

That what my setup does anyway.

Mine does too... A

[petefj40]

My dual battery setup is meant to leave one battery soley for the truck. The other solely for the 10 spot lights i have setup on the cruiser as well as the winch. I'm keen to see how it perfoms onces it's together.

[petefj40]

I can see one problem with this setup. lets say you have computer controlled injection, you turn your truck off and run your isolated battery so stupidly flat, it cant supply any power at all. Now when you come to start the truck, yes the motor turns over, but the isolated battery has no power to trigger the ignition, ecu, fuel pump etc. ne way I can see away around this is maybe having a secondary switched wire between the 2 batteries, bypassing and isolater switch and if you run the acc battery flat, you can flick this over and power up the ecu and fuel pump. alternatively you can run the ecu ignition etc directly off the starting battery through relays.

Easy, fit one of these,
http://www.projecta.com.au/catalogue/cid/23/asset_id/53
I have one and all you need to do is pop the bonnet, push a button and jump start yourself, easy as.

I have a 150A one fitted below the drivers seat. No need to pop the bonnet. Just push the button.
It works really well.

[curious_george]

I have one of these installed in a vehicle I modified for work. Admittedly it is the 24v version, but it's a brilliant piece of kit, and we're supporting NZ made at the same time.

http://www.bepmarine.com/300Amp-Voltage-Sensitive-Relay-(VSR)-166-1470.html

We have it installed in a Unimog, which has a second set of batteries on the back to run the lighting and inverter for our workshops repair vehicle. It works a treat, allowing us to run anything we like from the back and still allowing starting from the main batteries. There is also a remote wire, allowing a button installed in the dash to provide power from the house batteries to assist with starting when the apprentice has left the lights on!



The main advantage I can see of this unit over some of the others I have seen is the enormous amount of current that the unit can handle when in "starting assist" mode - well in excess of others I have seen advertised.

[Moriarty]

I am Curious, George, (sorry. {NOT} about the dreadful pun) wonder what cost? would be practicable for me to change to that better device, allowing a substantial revers current for starting?
Or just install a manual isolating switch in the cab, so if the service batt DID (and bloody well does) go flat, I can start again?
Be cheaper too.....
First time I was lucky, was on the long downhill slippery slope, managed to roll start.

Jumper leads live in the truck as a matter of course, part of my 4wd kit.
But I was wondering about the electric winch guys. a manual switch, less to go wrong, and then double the batt capacity for a harder recovery? Comments?

B.

[curious_george]

I am Curious, George, (sorry. {NOT} about the dreadful pun) wonder what cost? would be practicable for me to change to that better device, allowing a substantial revers current for starting?
Or just install a manual isolating switch in the cab, so if the service batt DID (and bloody well does) go flat, I can start again?
Be cheaper too.....
First time I was lucky, was on the long downhill slippery slope, managed to roll start.

Jumper leads live in the truck as a matter of course, part of my 4wd kit.
But I was wondering about the electric winch guys. a manual switch, less to go wrong, and then double the batt capacity for a harder recovery? Comments?

B.

Hi mate, sorry for taking so long to reply, I've just come back from Aussie with work.

Depending on the model that you can purchase, I believe the latest one can handle up to 500amps continuous and 2500amps cranking - more than enough I would imagine for any winching and definitly enough for starting. There is the option to run the unit in complete auto mode, or manual - allowing you to decide when you want to have the link connected or not. This would be advantageous when doing a winch job when you may or may not want to draw from the start battery. This is also easily switched on the unit - depending on where you mount it. It does come with a remote though.

I think the 24v version we purchased was around the $180.00 mark - quite cheap for the technology etc you are getting and I would imagine the 12v version being slightly cheaper.

As for installation, it's very easy. Power in, Power out and a ground wire. The remote just plugs in to a socket already on the unit - dead easy.

I hope this answers a few questions and certainly if there are any more, just ask - sorry again about they delay.

George

[Landcruiser70]

I see from capitol instruments the 100a and 200a are about the same price. I guess its best to go for the 200a?

[Gofer]

FYI, im about to dual battery my escudo to run the spots off and found a cheap way to isolate the battery yet have a minimum voltage kick in. Jaycar sell a 1,5 amp battery maintanance box whixh cuts off at at a high voltage and kicks in at 11 odd volts all one needs is a heavy dudty relay so the unit can switch the solinoid on the relay and there we go. The box was $36 plus GST and i got heavy duty relay from a wrecker for $10.

Now i have my battery for the standard car electrics and the second for every thing else which is kept charged by this little set up for under $50.

[wjw]

11 volts is probably too low, on my truck if it drops below about 11.4 then it struggles to start.

[Gofer]

Yes might be but my Zuky starts when u just at it..........i just walk past it to get to my bike and it thinks its going for a ride and fires up lol.