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ARGOFET alternator cable fusing

Should I FUSE the cable connection between the alternator B+ output and the Argofet Input ? On which side (close to alternator or close to argofet ?)

THe alternator has a rated output of 55A (Hitachi LR 155-20 for Yanmar) and the cable is 35mmq, than can carry all of the current. I don't believe there can be a fire risk on the cable, if there is a short on either side of the cable. May be the alternator can burn if it sees a short at the output, but I cant fuse less than 55A, and If I use a larger fuse I don't think there is much more short circuit current enough to blow a say 70A slow fuse.

ANy recommendation ?



abuonocore asked

0 Answers

Off grid installation with a 2. battery and ARGO Diode


I run an island system at home (currently with a 48V/120 AH LiFePo battery and a Smart Inverter 48V/3000W, as well as 9 solar panels with 150/35 Victron MPPTs).

Now I would like to integrate a 2nd battery pack 48V/50Ah with its own BMS.

That is, the charging current should come from the MPPTs, but no current should flow backwards to the inverter. I would like to supply a different circuit on this 2nd battery.

Could I interpose an Argo diode battery separator on the incoming side (from the MPPTs) and then connect the two batteries there?

The Argo diode battery separator is actually intended for the charging current from the alternator!

Thanks for helping

tbecks asked

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Cyrix-CT / Argofet Isolator with Supercapacitors

Hi, does anyone knows can a Cyrix-CT Battery Combiner or a Victron Argofet Battery Isolator be used to connect my w204 AGM starter battery and a pair of 100F Supercapacitors for my audio? My car has "Alternator Management" under my spec sheet.

If possible, which is preferred? Any advice will be greatly appreciated and thank you in advance.

Best Regards

davidw asked
davidw edited ·

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Victron Energy Argo FET Battery Isolator (3 batt) - Need help!

Newbie to the forum...

I’m hoping someone can help me.

I purchased the Victron FET Isolator thinking this would be a simple task; connect the charging circuitry to the “IN” and batteries to the outputs 1, 2, 3...simple...right?? Well, I can't figure it out.

Here is the problem...Referring to the wiring diagram below...The batteries are charged by either the converter or the alternator in the engine compartment. The same wires that provide the charge to the batteries also supply 12Vdc to the 12Vdc fuse bay that powers all the 12v circuits in the coach.

The green lines in the circuit represent the original wiring configuration...as one can see, the batteries are in parallel, and all connect to one point.

My goal was to avoid putting all the batteries in parallel by using the isolator and install 3 fuses and 3 switches so I could switch in/out any battery combination I wanted...including having a emergency spare.

To complicate things...the “E-Start Sol” is a momentary switch connects the engine battery to the coach batteries; this is in case the engine battery goes dead, you can start the engine from the coach batterie(s).

I can't figure out how I can connect up the "IN" on the isolator and still maintain the functionality. I'm not sure it's possible to incorporate the isolator and I might have to just connect the output of the switches to the common point like the original circuit.

I was thinking that perhaps I could find the 12Vdc outlet of the Converter and run that to the "IN" of the isolator, but then the issue is the E-Start Solenoid connection which is to connect all the batteries together...can't seem to figure that out using the isolator.

circuit to Victron.jpg

jusplainwacky asked

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One more Argofet Isolator Question - Energize Optional?

As someone trying to install one of these isolators I have searched high and low to try and answer my question. Jeff from Yacht systems has multiple YouTube videos but seems to gloss over most of the important details of the install. I find Victron installation instructions bland and lacking in explanation making the diagram irrelevant for most real world boat applications.

The Isolator Negative and energize connections are shown simply and without advice on purpose or placement. Also there are several posts that discuss back-feeding issues; blowing fuses and funneling power through what is supposed to be only a low amperage circuit. There is very little description of what this circuit is doing inside the Argofet or the Argo Diode systems.

I am hopeful people that understand these can try to compile answers here for others to understand more easily as well as help my own situation.

My application: 2001 Chaparral 240 Signature single engine Mercruiser 5.0 w/ 70 amp alt (3 wire), two AGM group 31 Batts, 4 position switch, currently a 20 year old Guest diode isolator, and wired in typical fashion with the alternator B+ output to the starter post then back to the isolator and then batteries.


#1 On an application with a typical stock internally regulated mando, mercruiser, GM style alternator. How relevant are the energize inputs on these isolators in that setting? Victron manual states the Energize circuit is optional...

(seems it would be nice to keep it simple and avoid back-feeding issues by omitting the positive energize connection)

#2 If it is not used what will the unit not be able to accomplish? (will voltage drop be higher without?)

#3 Is anyone able to confirm that the energize circuit is truly only needed for older alternators that do not have a self excite, or an externally regulated alternator? (if truly optional who can omit?)

#4 If the Positive energize connection is needed... -

Diagrams show that it is spliced into the alternator Sense position. Will this not back-feed through the harness to other loads? I am assuming I can not simply wire this directly to my alternator and separate the sense (purple) from the rest of the harness. I would imagine that would disrupt an input to the PCM and confuse something important. It is hard to tell weather the isolator wants to output a voltage at the excite or input a voltage from the excite.

#5 Could someone clarify the purpose of separating the charge current path from the Isolators point of view. (remove daisy chain from alt to start, and wire direct to batt/isolator.)

I really hate the part in every video from Pacific yacht systems where the installer states "I am not going to go into details why".... but then elaborates on needless points the rest of the video, just adds to the mystery.

-Is this only to maximize the voltage and limit the drop through the multiple connections?

#6 Can the same answers be applied to the ArgoDiode series of isolators?

Thank you to anyone who is able to contribute.

Photo shows Victron suggested install diagram. D+(61) = energize circuit


mcroni19 asked

0 Answers

Torque for ARGO FET M8 bolts

Anyone who has information about recommended torque for 8mm bolts on ARGO FET?


0 Answers

Argodiode 180A 3 outputs with no D+ in car


I want to install second battery on a van (Peugeot Traveller), and I have that argodiode with 3 outputs. But I cant find (And I search a lot...) D+ wire or fuse o similar, so I dont use it. Because as diagram indicate, D+ input must be connected on the side of the battery indicator, oposite of the wire that goes from that light, to the alternator. Cant find...

So, I Connect everything else, in normal config.. Alternator wire to input, and car battery+ to output 1 (I don´t connect at this moment second battery). But the car won´t start, as indicate "ECO MODE". It seems ECU signal problem... perhaps because I don´t connect D+ input. Don´t know.. anyway.

But I notice some things... with that 2 wires connected, each one in their position, and engine off, I have 12v (12.4 or similar), on tevery clamp!. Input and output1 (and Output2 and ouput3, that don´t haver wires). I think is because Output1, that goes to main battery has 12v. Is normal 12v also on input?? and on output2 and 3?

But as the car don´t start, well... I also connect on the input clamp, the wire from the main (Car)battery. I know.. that is not correct... But I want to make a bridge looking from the normal car config.

So, in the input clamp, I have wire from the alternator, and wire from main car battery. Together. And the car START ok!. All is working fine on the car. With that config, I ALSO have (like normal config), 12v on every output (engine off), and 14v on every output (engine ON).

I have some doubts.. Is normal, that in normal config, I have 12v on each outputs?? What happens If I connect second battery on output 2, if there are 12v, from main battery? It is not supposed is a Isolator? Is the normal config!, with input to the alternator and main battery to output1.

And with TWO wires (Alternator and main battery), connected to input, I also have 12v (off) and 14v(on).. so.. Can I connect second battery to the output?, leaving output1 empty?

xlman asked

0 Answers

Voltage drop Victron argo FET

Good morning,

I have installed on my boat a Victron ARGO FET 200. The device is connected on one side with the engine battery, on the other with 4 batteries for services.

I have the following problem: with the engine running I register 13.7 Volt on both banks of batteries. If the demand on the service batteries is high (even if for short period - i.e. the use of the bow thruster) the voltage on the engine battery drops below 13 Volt ( 12.7 Volt). This generate an alarm warning on the engine circuit ( Volvo Penta MDI system) set to run over 13 Volt. Is there any way to overcome the problem of voltage drop? Many thanks for any help.

Kind Regards


marco-biroli asked

0 Answers

Charging 3 battery packs from alternator/solar/ac


I have the following situation on my boat:

- starter battery connected to alternator

- aux battery

- bow battery

I want to achieve the following:

- charge all when on AC shore - this is done, I have 3 output ac charger with each seperate line going into them (existing sbc 500 adv fr)

- charge all from alternator

Right now, I have an emergency connect that connects in parallel starter and aux, and also use this for charging. But this is not a proper 3 phase charger, and I have a feeling it can mess with aux batteries. The bow does not get charged from alternator (but in emergency I can connect in parallel in same way).

- solar

Now I also want to add solar, to charge aux and bow (starter battery is fine w/o solar). Is there a good way to do this with 1 MPPT?

Any ideas/suggestions? I want systems to be independent, not for these sets to discharge between themselves. They do share common NEG right now (but this can be changed).

I was looking through different schematics and posts here (and elsewhere).

One proposal/idea is:

- for alternator

Add Orion to receive alternator input, and connect that one through argofet to both aux and bow (starter gets charged directly from alternator bypassing Orion).

- solar

Add one mppt, which is also connected to same argofet as above.

Is this ok? Basically I do not want to have any of packs in parallel, so want to isolate charging like this if possible.


ilautar asked

0 Answers

Not sure how to wire Yanmar Hitachi alternator to Argo fet 100-3 with connections to house bank and starter battery?

I need detailed wiring diagram showing how the excite circuit is wired. Also my alternator goes to my starter then the isolator input. Is this a problem?

shawn0900 asked

0 Answers

ARGO-Fet enrgizer signal

shall I connect 12 volt into the energizer Chanel for provide charge signal to alternator? Or is this an output chanel? If its an output, what is the voltage?

flytten asked

0 Answers

Buck boost with Argofet

Hi I am setting up a 12v 4wd battery system on a 79-land cruiser, which comprises of a 200amp lithium battery and lead acid starting battery.

I have an upgraded 200amp alternator and have purchased a BMV-702 & 100amp DC/DC Buck boost.

My question is can I introduce the Victron ArgoFET 200-2 between the alternator and buck boost/ battery’s?

My understanding is this would completely separate the charging supply of the starting and axillary battery and never allow the two to be connected reducing the risk of draining the starting battery in anyway.

ian-steele asked

0 Answers

AgroFet Blaue LED leuchtet ohne das die Lichtmaschine aktiviert ist (Motor aus).


Ich habe einen AgroFet mit 3 Ausgängen im Schiff verbaut. Starter Batterie auf Out 3, Verbraucherbatterie auf Out 2, Navi auf Out 1. sobald ich alle Hauptschalter auf "on" schalte liegen die jeweiligen Spannungen an den Ausgängen an.

Auf dem Eingang liegen komischerweise 8,4 Volt bei 0,4 A an. Die Blaue LED leuchtet dauerhaft.

Nehme ich dann das Lichtmaschinen Plus Kabel vom Input liegt auf diesem Kabel 0V und die blaue LED bleibt an ! Alle Batteriebänke haben 24v .

Nach starten des Motors wird die LED heller !

Bin für jeden Tip Dankbar !



I installed an AgroFet with 3 outlets in the ship. Starter battery on Out 3, consumer battery on Out 2, Navi on Out 1. As soon as I switch all main switches to "on", the respective voltages are applied to the outputs.
Strangely, the input is at 8.4 volts at 0.4 A. The blue LED lights up continuously.
If I then take the generator plus cable from the input, this cable is 0V and the blue LED stays on! All battery banks have 24v.
After starting the engine, the LED becomes brighter!
I'm grateful for every tip!


belle asked

0 Answers

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