Charging Voltage Low

OH and it mnakes no difference what RPM the engine is set on the voltages DO NOT change.

where are measuring the voltages?...at the battery terminals or at the alternator?.....
might be worth measuring at the alternator (if your not already) and if the voltage is ok there under load then hook the red arc up direct from there

Hi Matt

How old is the Redarc ?

It may be a early one that would disconnect close to 12.8V but the new ones are just like our DBi-120 and disconnect at 12.4 to 12.5 volts.

Your alternator may need a bot of a tweak but if the isolator is working correctly and the auxiliary battery is drawing amps it should stay engaged.

Have you got the serial number of the Redarc or send it to me to test.

What is the voltage at the main battery with the a/c and lights on and the engine at 2000 rpm ?

Regards

Derek.

OK Matt

Please give me these voltages with the engine at 2000 rpm and a/c and lights on.


1) Main battery (use the + and - posts)
2) Alternator (use the + on the alternator and the engine as the -)
3) Isolator input (use the input as + and the body as -)
4) Isolator output (use the output as + and the body as -)
5) Aux battery (use the + and - posts)

Now fit a earth jumper to the isolator (does any of the above voltages change ?)
Now fit a earth jumper to the aux battery (does any of the above voltages change ?)

Please make accurate notes and post them here or email me.

Regards

Derek.

Matthew,

I've got an adjustable regulator that makes things easier on my 61 series LC. You may be able to get one fitted to your vehicle instead of what I guess is a solid state regulator. There are also after market regulators around - three stage chargers - that might be helpful, sorry I don't have the links.

I also found Redarc would adjust the cutin/cutout voltages is you ask them nicely. You have to post the little black controller unit back to them after talking to them on the phone and seeing if they will still do it.

Tim

"What tells the voltage regulator to raise or lower the sytem voltage ,what is the sensing voltage taken from because this system is very low and i cant understand why.

Please help me!!!!!!!!!

Matt"

There are two types of Alternators -

- Internal sensing - most aren'et adjustable so you can't change anything.

- Remote sensing - these have a separate wire connected to the battery. If there's any resistance in the wire, it'll cause the Alternator to put out a higher voltage to bring the sensed voltage back to the setpoint. You can take advantage of this and put a Diode in series with this wire to raise the Alternator output voltage by 0.7 volts.

A failed diode (or 2) in the alternator?

"NOW when it is idling and the redarc has switched on to connect the deep cycle up the voltage sits at 13.6 volts with nothing on."

- most cars while not put out much current when idling - to do a voltage test you really need to have the engine at 1500rpm at least.

My NS Pajero Diesel will put out 25 amps at idle, but since Diesels have lower peak revs than a petrol engine and better low-revs power, it's easier to design a Diesel to charge at idle.

Matt,

i had a similar problem with one of my older commodores,i put the later voltage sensing alt on it and didnt improve it much,a mate suggested running the volt sense wire to the ignition as losses occur in the wiring as they get older.problem solved after that,better charge volts with lights on at idle.cheers Paul

The voltage and current are two different things. You should alway get close to 14.4 when the truck is running. You are right that the current (AMPS)is lower at idle but only becasue the amount of current required to the stato to create enough magnetic feild to create enough amps is not there. IE, the quicker you can get he alternator spinning the more amps with less amps requird from the batery to make those charge amps, it can be a cycle of loss if there is damage to the charge system, that's what the regulator does work out how much power to provide BACK to the alternator to help creat amps to chage and run the system.

The amps put out at a rev range is all in the winding. not petrol verse deisel though. It is a common mistake that ideling your truck will while on camp will really do much good. You will get a few amps but not the full amput, But, you will get 14.4 volts but that's not what relaly runs that fridge.

Have you taken it through any mud - dirt etc lately, You may have some muck in the bushes or some interfering in the rotor/stator which is limiting the amount of pwer that can be produced

The voltage and current are two different things. You should alway get close to 14.4 when the truck is running. You are right that the current (AMPS)is lower at idle but only becasue the amount of current required to the stato to create enough magnetic feild to create enough amps is not there. IE, the quicker you can get he alternator spinning the more amps with less amps requird from the batery to make those charge amps, it can be a cycle of loss if there is damage to the charge system, that's what the regulator does work out how much power to provide BACK to the alternator to help creat amps to chage and run the system.

The amps put out at a rev range is all in the winding. not petrol verse deisel though. It is a common mistake that ideling your truck will while on camp will really do much good. You will get a few amps but not the full amput, But, you will get 14.4 volts but that's not what relaly runs that fridge.

Have you taken it through any mud - dirt etc lately, You may have some muck in the bushes or some interfering in the rotor/stator which is limiting the amount of pwer that can be produced

Correct me if I am wrong, but I have not seen anyone suggest disconnecting the auxiliary battery circuitry or Matthew state that he has tested the alternator with it disconnected. This is the first thing that should have been done. If the load placed on the alternator by the auxiliary circuit is too great it does not matter what you do to the regulator - you will not get full voltage.

Disconnect the Redarc and run the truck for a few days and see if the charging circuit acts OK. Make up a lead to connect your volt meter to some 12V source that is not affected by voltage drop by other accessories on the same circuit when they are switched on. I have used the cigarette lighter socket successfully in some vehicles. Connect and switch on the meter before starting. Shortly after starting the meter indication should rise to over 14V. The voltage should then commence to drop as the engine compartment heats up and when you have driven for half to one hour it will drop to somewhere between 13.6 and 13.9V. Monitor this whilst you are driving for the next few days until you are getting the same peak reading when the motor is cold.

If the the alternator has been shown to work without the extra load then your problem is in the auxiliary circuit. The problem will will probably the Redarc (least likely) or the battery (most likely.) You may need to take your battery to someone with a good battery charger or purchase a three stage charger for your van and use that. Perhaps you should do that whilst you are testing your alternator, take it to a supplier of deep cycle batteries and get it worked over before it sulphates up.

PeterD

Mainey

I can comprehend it all BUT i was just expecting a little more from the system than i am getting and would like to upgrade the charge voltage when loaded.

Like today its 39 degrees here as you know and the thing wont charge over 13.2 with aircon on,i mean how much is it going to drop down to if the thermo fans come on or the fridge cycles.

Very frustrating because i know that it should perform better.

Matt

Yeah i know what your saying ,i just like to see bigger numbers when i got a lot of stuff running.

I am going to disconnect the deep cycle and drive it for a few days over the weekend and see how it goes on that alone.

MAtt