Victron 100/30 MPPT conundrum

[robertager1962]

I have just installed a Victron MPPT Controller ànd am having an issue at night as it loses power. I have discovered that the Victron charge splitter((ARGO FET Battery Isolator) that I fitted earlier this year is preventing the MPPT controller from receiving the power from the batteries to keep it energised when the solar stops working.
My question is can anyone see an issue with using a fused cable with a diode to provide a separate supply to the MPPT.

 

[Sandy]

How have you connected your MPPT to the battery?

In my set up I connect directly to the leisure battery bank, with a fuse. No problem with the MPPT getting power.

 

[RupertW]

How have you connected your MPPT to the battery?

In my set up I connect directly to the leisure battery bank, with a fuse. No problem with the MPPT getting power.

Provided it’s not on the battery side of the shunt then that’s fine.

 

[PaulRainbow]

I have just installed a Victron MPPT Controller ànd am having an issue at night as it loses power. I have discovered that the Victron charge splitter((ARGO FET Battery Isolator) that I fitted earlier this year is preventing the MPPT controller from receiving the power from the batteries to keep it energised when the solar stops working.
My question is can anyone see an issue with using a fused cable with a diode to provide a separate supply to the MPPT.

You cannot connect the solar controller to the ArgoFET, it needs to go directly to the batteries. Positive straight to the positive terminal, or to the isolator switch if easier, with a fuse. Negative the negative post, or the load side of the shunt (if fitted) as per post #3

 

[Daverw]

if rewiring is not quick, assuming you’ve got it on the same terminal as the alternator input on the Argofet, moving it to the battery output terminal should work, Paul could confirm this as this should go straight to your house battery’s

 

[robertager1962]

How have you connected your MPPT to the battery?

In my set up I connect directly to the leisure battery bank, with a fuse. No problem with the MPPT getting power.

No not a direct connection to the battery as it is going through

 

[robertager1962]

You cannot connect the solar controller to the ArgoFET, it needs to go directly to the batteries. Positive straight to the positive terminal, or to the isolator switch if easier, with a fuse. Negative the negative post, or the load side of the shunt (if fitted) as per post #3

Thanks. Any idea how I can charge my house batteries as well as the engine batteries from the solar? I can't believe that I am the only person who has experienced this issue, seems odd that Victron have not addressed this issue

 

[RupertW]

Thanks. Any idea how I can charge my house batteries as well as the engine batteries from the solar? I can't believe that I am the only person who has experienced this issue, seems odd that Victron have not addressed this issue

Most people only charge house batteries, there is rarely a reason to give engine batteries an extra charge even if left for a few months.

 

[Buck Turgidson]

Thanks. Any idea how I can charge my house batteries as well as the engine batteries from the solar? I can't believe that I am the only person who has experienced this issue, seems odd that Victron have not addressed this issue

Bin the FET and fit a VSR. Solar should go straight to house bat as Paul said.

 

[PaulRainbow]

if rewiring is not quick, assuming you’ve got it on the same terminal as the alternator input on the Argofet, moving it to the battery output terminal should work, Paul could confirm this as this should go straight to your house battery’s

Yes, that's right Dave. I'd still fit a fuse between the controller and the ArgoFET terminal.

 

[Sandy]

Thanks. Any idea how I can charge my house batteries as well as the engine batteries from the solar? I can't believe that I am the only person who has experienced this issue, seems odd that Victron have not addressed this issue

My set up is has a Voltage Sensitive Relay (VSR) in the system so that when the voltage gets higher than 13 volts the VSR then connects the house and engine thus charging both. When it falls below 12.7 volts it disconnects.

I might be unusual, but the alternator is wired to the engine battery and solar/shore power to the house. My logic is that the engine battery should be charging as a priority when under power and the house battery when under sail.

Looking at the output from the solar panels this month I can see 5 amps being generated and the shunt recording 3 amps into the house, logically the balance if going to the engine battery. Note these figures are given as an example and not the actuals.

 

[geem]

Thanks. Any idea how I can charge my house batteries as well as the engine batteries from the solar? I can't believe that I am the only person who has experienced this issue, seems odd that Victron have not addressed this issue

You put the solar direct to the house bank and use a Victron orion to charge the engine battery from the house battery. That what we do. We also charge the generator battery this way rather than using the alternator on the genset. At anchor, the engine and generator batteries get a perfect charge plus float, all at the flick of a switch

 

[geem]

Most people only charge house batteries, there is rarely a reason to give engine batteries an extra charge even if left for a few months.

Being different, we use an Orion B2Bm o keep the engine battery charged. Thr windlass runs from the engine batteries. We often use the windlass to lift the dinghy at night. Keeping the engine battery fully charged then on float is a must for us.

 

[Daverw]

We have alternator charging starter and then house via Argofet solar to house, the starter rarley needs topping up, if it does the Multiplus will trickle charge it via shore or house, solar direct to house

 

[robertager1962]

Thanks to you all for your advice. I see now that it was the Argo Fet splitter that was the culprit in this. We live aboard and our yacht (unfortunately) spends a lot of time being our house, so it is easy for the engine batteries to be forgotten and I fitted the splitter to prevent this.
I have a Victron 2kw inverter charger (that have just fitted and am learning how to drive) that has a 4 amp charge output for the engine batteries and will use this.
Shame to consign the splitter to my (filled to bursting) locker though.
Very difficult to justify the costs involved to my wife with all the new electrical kit I have installed to help save money by using solar instead of shore power

 

[emmalina]

I use a diode and a 10R resistor to trickle charge the start form the house batteries works for me.

 

[PaulRainbow]

Thanks to you all for your advice. I see now that it was the Argo Fet splitter that was the culprit in this.

Sorry Roger, but it wasn't the ArgoFET that was the culprit, it was you
It's doing exactly what it's meant to do, you just wired the solar controller up incorrectly.

We live aboard and our yacht (unfortunately) spends a lot of time being our house, so it is easy for the engine batteries to be forgotten and I fitted the splitter to prevent this.
I have a Victron 2kw inverter charger (that have just fitted and am learning how to drive) that has a 4 amp charge output for the engine batteries and will use this.
Shame to consign the splitter to my (filled to bursting) locker though.
Very difficult to justify the costs involved to my wife with all the new electrical kit I have installed to help save money by using solar instead of shore power

No need to remove the ArgoFET, it will keep all batteries charged when the engine is running. The inverter will keep everything charged when on shore power and the solar will keep the domestics charged.

You don't say how much solar you have, but be warned, if you leave the shore charger on there won't be anything for the solar to do. You'll wake up in the morning with fully charged batteries (from shore power) and there will be nothing for solar to do. I'd leave the mains charger off and have a low battery alarm, turn the mains charger on if it goes off.

If you don't have one already, fit an emergency parallel switch between the load terminals of the engine and domestic isolators.

 

[Baggywrinkle]

@robertager1962 .... You can use an Argofet to keep the MPPT live when the sun goes down.

The 3 caveats are that it has to be an Argofet with an "Energize" input, the battery banks have to be the same chemistry, and the MPPT needs to be the only thing connected to the Argofet Input (No alternator/engine electrics)

How to do it .... from the Victron Argofet description ...

Alternator energize input

Some alternators need DC voltage on the B+ output to start charging. Obviously, DC will be present when the alternator is directly connected to a battery. Inserting a Diode or FET splitter will however prevent any return voltage/current from the batteries to the B+, and the alternator will not start. The new Argofet isolators have a special current limited energize input that will power the B+ when the engine run/stop switch is closed.

https://www.victronenergy.com/upload/documents/Manual-Argofet-EN-NL-FR-DE-IT-ES-SE-TR.pdf

This Energize input can also be used to provide power to run an MPPT, even though it was intended to provide an excitation current to older alternators.

I have done exactly this in my camper van with a Argofet and a MPPT 100/30 because the vehicle has an isolation relay and a smart alternator which connects and disconnects the leisure batteries from the starter/alternator during engine start or when the vehicle is parked up. I did not want to bridge this relay.

My circuit diagram looks like this ...




Installed it looks like this .... the "Energize" input is on the left and connecting it to either of the battery banks will provide 12V and enough current to run the MPPT which is connected to the far right terminal in the pic.



If you have an Argofet with an energise, I guarantee this works. This has been installed in my camper van for almost 2 years and works flawlessly.