Continuous Duty Solenoid - Is it Charging the Aux battery??

[Seafarer]

Hi,

Can someone give me a heads up on how to go about checking if the auxilliary battery is charging when the engine is started when using one of these continuous duty solenoids?

Following readings taken using a multimeter:

1) Engine not started
Main = 12.86V
Aux = 12.58V

2) Engine started
Main = 14.0V
Aux = 12.56V

[drivesafe]

Hi Seafarer, the quickest way to check if the solenoid is working is to measure the voltage across the two battery connections on the solenoid.

Start your motor and then place a multi meter’s positive probe on the terminal with the cable coming from the main battery and the negative probe on the terminal with the cable coming from the auxiliary battery.

If you get a zero reading then the problem is not at the solenoid.

If you get something like a 1.5 volt reading then it’s a pretty safe bet the solenoid is the problem.

Cheers

[Seafarer]

much appreciated drivesafe.

[Seafarer]

Hi Seafarer, the quickest way to check if the solenoid is working is to measure the voltage across the two battery connections on the solenoid.

Start your motor and then place a multi meter’s positive probe on the terminal with the cable coming from the main battery and the negative probe on the terminal with the cable coming from the auxiliary battery.

If you get a zero reading then the problem is not at the solenoid.

If you get something like a 1.5 volt reading then it’s a pretty safe bet the solenoid is the problem.

Cheers

Drivesafe,

It measure 0.3V with engine not started and 1.2V with car started. Does that mean the solenoid is rooted?

[drivesafe]

It measure 0.3V with engine not started and 1.2V with car started. Does that mean the solenoid is rooted?

Sure looks like it, a new solenoid should solve your charging problems.

Before you do that, do a quick test to be sure.

Disconnect one of the battery cables from one side of the solenoid and connect it to the other side of the solenoid to the same terminal that the other battery cable connected to.

What you are doing is bridging out the solenoid and you should now have an increase in the voltage level of your auxiliary battery once the motor is running. If it does increase then the solenoid is definitely the problem.

WORD OF CAUTION, no matter which battery cable you disconnect from the solenoid, THIS CABLE IS STILL LIVE so don’t drop it or you could end up with a massive dead short.

Cheers.

[Seafarer]

Cheers Dude. You are a good man. Will give that a go later and come back with the results.

[Seafarer]

Drivesafe,

These are the latest multimeter readings:

Engine not started (solenoid connected):
1) Across positive terminals of solenoid = 0.23v
2) Main Battery = 12.79v
3) Aux Battery = 12.56v

Engine started (solenoid connected):
1) Across positive terminals of solenoid = 1.6v
2) Main Battery = 14.13v
3) Aux Battery = 12.56v

Engine started (positive of both main and aux battery connected - bridging out the solenoid):
1) Main Battery = 14.01v
2) Aux Battery = 13.84v

Suppose it means the solenoid is rooted and the last readings is what is expected if the solenoid is working properly.

Looks like a redarc is the goer but unsure which model to get. SBi12, SBi12LC, SBi12D etc etc. Any recommendation?

[drivesafe]

The type of dual battery controller depends on what you intend use the set for.

Can you give an idea of how you usually use your present set up.

Cheers

[Seafarer]

I currently have a 600W inverter, 2 spotties, UHF wired to the Aux battery. Moving forward at some stage I will be wiring up another ciggie socket and possibly a fridge.

Use of inverter and fridge would be pretty infrequent.

[alchemist]

Bloody Mike, get yourself a brand new RedArc.... that'll fix your problems buddy!

[Seafarer]

Bloody Mike, get yourself a brand new RedArc.... that'll fix your problems buddy!

Hello Dave,

Why are you messing up my thread for?



Looking at getting a redarc or a smart charger sometime this week. How's things over at WA? Hope the family is well.

[Cossie]

Have you checked the solenoid is actually getting the necessary power to switch it? ie ignition live and a good earth? (assuming its the old type of solenoid and not a smart type)

[drivesafe]

Talk about overlook the obvious, good one Cossie.

Cheers

[Seafarer]

Cheers Cossie and drivesafe.

The solenoid does produce a single click/thud sound when the ignition is first turned.

Will do a check later. Suppose the way to check it is by placing positive multimeter probe on the ignition terminal of solenoid and negative probe on negative terminal of Main battery.

[drivesafe]

Seafarer, test it as you posted anyway, but if you can hear a click when it’s powered up then it should be working and that would point to the contacts being stuffed.

BTW, if the solenoid is wired up to power up when you turn the ignition on, you were probably lucky the solenoid went first, because this type of install usually causes both batteries to be stuff, ( and you stranded ), before you realise you had a problem with either battery.

Cheers

[Seafarer]

Seafarer, test it as you posted anyway, but if you can hear a click when it’s powered up then it should be working and that would point to the contacts being stuffed.

BTW, if the solenoid is wired up to power up when you turn the ignition on, you were probably lucky the solenoid went first, because this type of install usually causes both batteries to be stuff, ( and you stranded ), before you realise you had a problem with either battery.

Cheers

Tested and reading is 1.2v. Subsequently, i hardwired a wire from positive of main battery to ignition terminal of solenoid and the aux battery is still not charging and showing 12.56v.

Drivesafe: Can you elaborate on "this type of install usually causes both batteries to be stuff" do you mean its a shortcoming of using solenoids?

[drivesafe]

Drivesafe: Can you elaborate on "this type of install usually causes both batteries to be stuff" do you mean its a shortcoming of using solenoids?

Hi Seafarer, in an earlier post you said that one side of the solenoid was wired to ignition.

If this means that when the ignition turned on, the solenoid will turn on and and both batteries will be connected to the starter motor.

If everything is working OK, there is no real problem with this BUT as a solenoid can energised ( turned on ) with voltages as low as 9 volts, if you have a stuffed cranking battery, not holding a charge or has a stuffed cell, it won’t normally be able to start the motor but it still has enough power to turn the solenoid on and in this situation, you are now starting the motor using just the auxiliary battery and there will be no obvious indications that the cranking battery is cactus until the auxiliary battery gives up the ghost.

Now you have two stuffed batteries.

Cheers.

[lexi]

Just to take that point further my system has a 70amp relay to connect the batteries this is triggered by a smaller relay which feeds from battery chargng light circuit. Would that address the potential problem you last spoke of?

Alex

[BundyBrumby]

I have wired the solonoid straight up to the ignition too

Thanks for pointing out the shortfalls with this arangement drivesafe.

Lexi, you are a genious!! i have been pulling my hair out for some time wondering how to do just that!!

[lexi]

Sorry guys it`s not a 70 watt relay I have it`s a about 100 watt. It`s got nuts on for the connections. Small relay that feeds it is about 30amp.

I got the tip about feeding the big relay from alternater charge light wire on here. Can`t remember the dude who gave me it but he was a lot smarter than me

Alex

[trains]

Cheers Cossie and drivesafe.

The solenoid does produce a single click/thud sound when the ignition is first turned.

Will do a check later. Suppose the way to check it is by placing positive multimeter probe on the ignition terminal of solenoid and negative probe on negative terminal of Main battery.

If you can pry off the top of the solenoid, carfully uncrimp the round top section, and clean the contacts inside, I rekon you will be good to go.

I had simmilar problems when nth of tarcoola in the middle of nowhere, and took it apart, cleaned it, works a treat, the contacts had corroded up due to age.

With some care and patience, you can reseal the top of it again quite well.

When I got the vehicle it was wired up to the ign, so when the ign was on, the solenoid brought both batts together as one.
I put in a simple on off switch on the dash, so when starting, I effectively disconected the 2nd batt, and once running, brought it back into the cycle to charge.
That way, if main batt dosent crank, I can bring in the 2nd batt and start, instead of the 2nd batt masking the fact that one batt is dead, till it too dies, and leaves me with nothing.

Hope that makes sence.

Trains