best way to connect 2 battrys together? with out piranha sys

[steveoo]

I recently installed a piranha dual battrey system in my truck GQ LWB. Was running with no problems. Was just runnign normal things off the second battry couple of lights UHF CD player. So i went out and purchased a Big Boss air compressor and this is where the problems began!!

After doing much research i decided to put the air compressor up to the second battry. If you know the specs of the big boss compressor it draws 110amps at running and at start 130amps peek. Half way through the cycle of filling the tank the second battry would go flat. After much scratching of the head i found out the piranha system turns off since there is too much current draw!!. Now where did it say that on the box...

So after finding this out i put it onto the first battry (starting battrey). and it ran with no problems

So now my problem is whats the best way to connect 2 battrys together.

since i got a winch going on soon.

[Jaffa]

....After much scratching of the head i found out the piranha system turns off since there is too much current draw!!. Now where did it say that on the box...

It's written on the front (current limiting)


To answer your question the easiest way to do what you are trying to do would be either to swap the Piranha system for a solenoid, or to run a heavy duty manual switch or solenoid in parallel with the Piranha system.

[steveoo]

i never realised, man i feel stupid now.......

looks like a trip to piranha to see if they got an solenoid for what i need...

[zackde]

Go a Redarc smart solenoid 400amp inrush rated.

[v6hilux]

For those that might be happy with a basic system, you can also use the solenoid off a starter motor if you want to isolate a second battery. You just need a switch in the dash and have to remember to switch it on to charge and off when you want to save the second battery!

The solenoid will need to be switched from the isolated battery in case you run down the first battery too much!

[BundyRumandCoke]

Nope, sorry V6Hilux, using a starter solenoid wont last. That was my original set up, till it shorted out, and sent a dead short back through the system, and blew the engine fuse, giving me nothing. Thats because, a starter solenoid is an intermittant duty solenoid, and not designed for continuous use.

Go to an auto electrician, and get a continuous duty solenoid. 4 terminals- 2 large (that you hook to each battery) and 2 small (power and earth) If you hook the power to the ignition, so the sonenoid is only active when the ignition is on, then charge will go to both batteries when engine is on, but batteries will be disconnected when ignition is off.

[v6hilux]

[quote="BundyRumandCoke"]using a starter solenoid wont last. That was my original set up, till it shorted out, and sent a dead short back through the system, and blew the engine fuse, giving me nothing. Thats because, a starter solenoid is an intermittant duty solenoid, and not designed for continuous use. [/quote]

I mentioned the solenoid, as it's just for starting and charging the starting battery. It isn't for 100% usage, like you said.

Perhaps your particular unit was faulty or just the wrong type. Perhaps you didn't have a protection fuse for the circuit to the solenoid itself? Thats how to get a short you described.

Too many variables to discount it.

[steveoo]

does any one have a link to something which i should be looking for??

[4runner_boy]

This is what im using its simple and a very tough setup.Cont duty solenoids wont handle high current for very long,nor will a starter solenoid




http://db.hella.com.au/cgi-bin/catalogu ... maint=2113

[Rubiwan]

I have done what you want - I wored two cole hursey 400A solinoids in parrallel to creat a 800a switch

works fine and cost under $100 to set up

Ado

[mavzilla]

silver contact solenoid from the auto elecy(400 amp) about 40 bucks , been goin for 5 years including a lot of winching. Solenoid with the big screw posts for battery cable and smaller for switching wires

[Ruffy]

After doing much research i decided to put the air compressor up to the second battry. If you know the specs of the big boss compressor it draws 110amps at running and at start 130amps peek. Half way through the cycle of filling the tank the second battry would go flat.

I don't think these figures sound terribly accurate? A 4cyl petrol engine starter motor only draws a little over a 100amp @ crank.
I think the big boss would be under 50.
Given that i don't see why your second battery would be going flat so quickly. How big is the tank and how long does it take to fill?
I understand you want to change the system but you may have another underlying problem.
Cheers Dan

[Rubiwan]

Ruffy,

Sorry but statermotors pull alot more than 100amp - some pull up to 700a as they start

Stevoo I'd do as I said before jsut get a constant current solinoid and use it to parrallel the batteries when you draw large loads

However Ruffy may have a point - my Probag cpompressor pulls 65A and it'll run 20min easy on my main battery wothout the motor running and indefinately with the motor rinning

So perhaps your battery is stuffed or isn't being charged properly

Ado

[blkmav]

See Hobzee http://navrun.com.au/battery.htm

[Cossie]

Why not just run it from your main battery? If it's pulling that much current you should be using it with your engine running anyway.

[steveoo]

i thought by having it off the second battry it would level out the amount of load on 1 battry onto 2 battry

[Cossie]

With the engine off the batteries would be seperated so you'd be running it pureley from whichever one its connected to.

Compressors are typically high current draw items that can run for a reasonable amount of time (dependant on tyre size/pressure etc etc). I would always recommend having the engine running whilst using it.

[midi73]

Get one of these.
http://www.sidewinder.com.au/page82.html

[bogged]

Get one of these.
http://www.sidewinder.com.au/page82.html

Derek is very good to deal with. Bought a redarc for mate last week, had it in 2 days.

[Jaffa]

.....Given that i don't see why your second battery would be going flat so quickly. How big is the tank and how long does it take to fill?
I understand you want to change the system but you may have another underlying problem.
Cheers Dan

The problem will be because of piranha systems safety cutouts, it will switch off for one of two reasons in this case, either because of excessive current draw through the isolator, or more likely because the voltage across both batteries is dropping "too low" and the piranha system shuts off (directs all charging current to main battery)

[Ruffy]

Ruffy,

Sorry but statermotors pull alot more than 100amp - some pull up to 700a as they start

Stevoo I'd do as I said before jsut get a constant current solinoid and use it to parrallel the batteries when you draw large loads

However Ruffy may have a point - my Probag cpompressor pulls 65A and it'll run 20min easy on my main battery wothout the motor running and indefinately with the motor rinning

So perhaps your battery is stuffed or isn't being charged properly

Ado

Thanks for trying rubiwan, but i do it every day.
Once cranking a small petty 4 cyl will draw 100 to 150 amps.
You are right, some starters draw 700 amps... but none that fit the description i mentioned so telling us that was irrelevant.
Just checked the website, stats say current draw for the Big boss is 45 amps. So if yours is drawing over 100 then its faulty.

[Ruffy]

.....Given that i don't see why your second battery would be going flat so quickly. How big is the tank and how long does it take to fill?
I understand you want to change the system but you may have another underlying problem.
Cheers Dan

The problem will be because of piranha systems safety cutouts, it will switch off for one of two reasons in this case, either because of excessive current draw through the isolator, or more likely because the voltage across both batteries is dropping "too low" and the piranha system shuts off (directs all charging current to main battery)

WTF? How is the system cutting out going to make the battery go flat quicker?
The battery shouldn't be going flat that quick regardless of they system stop it from charging.

[jaztaz]

Is the redarc the same sort of setup as pirahna? I run 2 spotties & 1 fridge off my aux battery & same thing happened.

[steveoo]

the big boss saids it should be sucking about 100amps from my understanding they recommend a 110amp fused line and reacomend 2 gauge wiring...

this is what steve hobbys said when purchased

[Ruffy]

http://cgi.ebay.com.au/BIG-BOSS-air-Com ... dZViewItem
Says "Maximum current consumption... 45 Amps"

[zagan]

No idea if this would work good, but couldn't you get something that increased the amp rating, from the second battery to the air compressor?

Like a transformer or something.

[cloughy]

No idea .

[steveoo]

wrong air compressor this is the one

http://cgi.ebay.com.au/BOSS-Air-Compres ... m153.l1262

[mikesmith]

the big boss mite pull 100 amp on start up but once going no way. they recommend such big gauge wiring to be able to withstand the startup amperage.

rather be safe than sorry.

like the twin thermos i have take around 30 amp to start but dont draw near that once going. so i have a 30 amp fuse and wiring to suit that amp draw.

[chimpboy]

I have done what you want - I wored two cole hursey 400A solinoids in parrallel to creat a 800a switch

works fine and cost under $100 to set up

Ado

Two 400A solenoids in parallel don't make an 800A switch. When one breaks the circuit the other will be carrying the full current.