Replacing Marlec with Victron 75/15 bluetooth controller

[stu9000]

Hi
I had a Rutland Wind generator but it stopped working in the January storms and I have not been able to get it going.
I bought two 115w solar panels which ive linked in parallel to a victron 75/15 mppt controller.
The old Marlec controller the wind genny fed into looked like this

Note the terminals for "batt1" and "batt2".
This was a nice feature that charged both the leisure and starter battery banks.

This is the new victron mppt controller


It only has one set of terminals for charging the battery which has me seeking advice on how to manage the starter and leisure battery banks.

Could I wire the leisure batteries to "load" and the starter to "batt"?

Or, should I just link the old wires for batt 1 (leisure) and batt 2 (starter) into the "batt" + and - on the Victron?
Would that mean the different banks are now linked (and that leaving the lights on could flatten the starter battery)?
Maybe I could fit a diode to prevent current reversal, but I really don't know what im talking about here.
A quick read suggests a voltage drop might be a drawback.

I could fit a one/two/both switch.
This would allow me to prioritize the charging to one bank or the other according to need.

Ideally, I would want the charge input to prioritise the starter battery until it reaches a certain point and then switch to charging the leisure bank.
There must be gizmo's or simple diode type stuff that does this.

What do other people do with their solar set up (don't say "buy a different controller")?

Thank you.

S

 

[Cuan]

The Marlec HRDi controller will also handle up to 160W solar panels. Its designed to handle inputs from solar and wind generator, so you could just stick with that. Mine just has solar input as i binned plan to get a wind generator - see for reference
https://www.marlec.co.uk/wp-content/uploads/2015/10/HRDi-Manual.pdf

 

[VicS]

Hi
I had a Rutland Wind generator but it stopped working in the January storms and I have not been able to get it going.
I bought two 115w solar panels which ive linked in parallel to a victron 75/15 mppt controller.
The old Marlec controller the wind genny fed into looked like this
S

No to most of what you suggest

A VSR, or perhaps a Victron Cyrix , is the way foward I think

You show what appears to be a BEP VSR switch cluster as an attachment but presumably you do not intend or need to replace your existing battery switching arrangements

This should be considered agonist knowledge of your existing battery switching and charging from the alternator and shorepower to produce an integrated and compatible system, Can you describe or better post a diagram of this

I would not prioritize the starter battery, The alternator should take care of that , but its up to you,itI wont make that much difference

Paul Rainbow will probably be the best person to take note of

 

[NormanS]

The Marlec HRDi controller will also handle up to 160W solar panels. Its designed to handle inputs from solar and wind generator, so you could just stick with that. Mine just has solar input as i binned plan to get a wind generator - see for reference
https://www.marlec.co.uk/wp-content/uploads/2015/10/HRDi-Manual.pdf

Yes, but two times one hundred and fifteen equals two hundred and thirty.

 

[HappyAfloat]

I wired my victron MPPT to the leisure bank and used a Votronic 12V StandBy Charger to trickle charge the starter bank.

 

[stu9000]

The Marlec HRDi controller will also handle up to 160W solar panels. Its designed to handle inputs from solar and wind generator, so you could just stick with that. Mine just has solar input as i binned plan to get a wind generator - see for reference
https://www.marlec.co.uk/wp-content/uploads/2015/10/HRDi-Manual.pdf

I was advised the the mppt was worth the spend as it makes the most of the available power. The Marlec is slightly older tech isnt it?

 

[stu9000]

No to most of what you suggest

A VSR, or perhaps a Victron Cyrix , is the way foward I think

You show what appears to be a BEP VSR switch cluster as an attachment but presumably you do not intend or need to replace your existing battery switching arrangements

This should be considered agonist knowledge of your existing battery switching and charging from the alternator and shorepower to produce an integrated and compatible system, Can you describe or better post a diagram of this

I would not prioritize the starter battery, The alternator should take care of that , but its up to you,itI wont make that much difference

Paul Rainbow will probably be the best person to take note of

Hi Vic. I am still puzzling out the details of how the previous owner put this together but the batteries must be in parallel if its 12v.. ...right?
The bow thruster battery seems to be linked to the starter battery.
Both sets of batteries link to the BEP VSR I accidentally included in my first post. All seems to charge well on the alternator so I have no plans to change the battery switch. There is a shorepower link as well but im on a swing mooring so don't use it routinely.

I hear what you say about letting the alternator charge the starter, but I was concerned about it being left for months on end.
I had a look at the Cyrix. It kind of makes sense. But im still working out how to combine it with the existing set up.

What is the risk associated with linking both sets of batteries at the mppt controller?

S

 

[stu9000]

I wired my victron MPPT to the leisure bank and used a Votronic 12V StandBy Charger to trickle charge the starter bank.

This makes sense:
VOTRONIC - StandBy Charger
"The VOTRONIC StandBy Charger serves for automatic recharging and trickle charge of the starter battery or the auxiliary battery, if the mains supply charger, the solar charging controller or the generator is equipped with only one charging port."

Under £30 so not too much of an additional spend.
Thanks

 

[PaulRainbow]

View attachment 89563
Hi Vic. I am still puzzling out the details of how the previous owner put this together but the batteries must be in parallel if its 12v.. ...right?

Correct

The bow thruster battery seems to be linked to the starter battery.

Not an uncommon way of charging the thruster battery. It's OK as long as the positive cable is protected at both ends by fuses/circuit breakers. I'd double check this, as i see a lot where there is only a breaker at one end.

Both sets of batteries link to the BEP VSR I accidentally included in my first post. All seems to charge well on the alternator so I have no plans to change the battery switch.

If you are saying that you have the switch cluster with the VSR (or even just the VSR) from post #1, then there is nothing that you need to do. The BEP VSR is dual sensing, it will detect alternator charging and close, to charge both banks and it will detect the solar charge and also close to charge both banks.

There is a shorepower link as well but im on a swing mooring so don't use it routinely.

Same again, if you turn the mains charger on and it's only connected to one battery bank, the VSR will close.

I hear what you say about letting the alternator charge the starter, but I was concerned about it being left for months on end.


I had a look at the Cyrix. It kind of makes sense. But im still working out how to combine it with the existing set up.

If you have the BEP VSR, all batteries will be charged, it would be completely pointless fitting the Cyrix. If you don't have the BEP VSR, i'd fit the Cyrix.

What is the risk associated with linking both sets of batteries at the mppt controller?

Both banks will be permanently in parallel, don't do it.

Also, don't connect batteries to the load terminals.

To sum up, if you have the BEP VSR, you should be sorted. Connect a voltmeter or multimeter to each bank when the solar controller is charging to confirm it's all working, both banks should read similar voltages.

If you don't have the BEP VSR, fit the Cyrix.

 

[duncan99210]

My panels are connected to the domestic bank only. During the season, when we (normally) live on board for three/four months, that’s fine, as the engine battery doesn’t need charging for the few days between engine use. During the winter, I turn the ”emergency” link between the domestic and engine batteries on, thus linking both sets of batteries to the solar system.
I’ve got a Sterling AtoB charger between the alternator and batteries, thus keeping the two sets separate in normal use.

 

[stu9000]

Correct



Not an uncommon way of charging the thruster battery. It's OK as long as the positive cable is protected at both ends by fuses/circuit breakers. I'd double check this, as i see a lot where there is only a breaker at one end.



If you are saying that you have the switch cluster with the VSR (or even just the VSR) from post #1, then there is nothing that you need to do. The BEP VSR is dual sensing, it will detect alternator charging and close, to charge both banks and it will detect the solar charge and also close to charge both banks.



Same again, if you turn the mains charger on and it's only connected to one battery bank, the VSR will close.



If you have the BEP VSR, all batteries will be charged, it would be completely pointless fitting the Cyrix. If you don't have the BEP VSR, i'd fit the Cyrix.



Both banks will be permanently in parallel, don't do it.

Also, don't connect batteries to the load terminals.

To sum up, if you have the BEP VSR, you should be sorted. Connect a voltmeter or multimeter to each bank when the solar controller is charging to confirm it's all working, both banks should read similar voltages.

If you don't have the BEP VSR, fit the Cyrix.

Thanks v much Paul, and everybody.
It maybe the wiring to the old marlec (which I'm using again) isn't routed via the VSR.
But I now have plan.
When I'm next on board I will check and re route if required.

Just to confirm, the VSR senses the charging input coming in and automatically Bridges all the battery banks, auto disconnecting them when the incoming charge stops...?

 

[VicS]

Thanks v much Paul, and everybody.
It maybe the wiring to the old marlec (which I'm using again) isn't routed via the VSR.
But I now have plan.
When I'm next on board I will check and re route if required.

Just to confirm, the VSR senses the charging input coming in and automatically Bridges all the battery banks, auto disconnecting them when the incoming charge stops...?

If yu have an HRDi ( which is what you showed earlier ) then you can simply wire it to the two battery banks

I deduce that you have the BEP VSR switch cluster installed ........ is that right ?
If so he VSR will still operate to link the battery banks once the voltage on one of them reaches the switch on threshold

If you have a VSR you do not need the dual output solar controller... You could use the Victron MPPT controller and allow the VSR to charge both banks just as it presumably does with the alternator output.
Wire it to the battery bank you want it to charge as first priority

When you finally decide on what you are going to do post a wiring diagram, showing the charging and switching, for comments

 

[PaulRainbow]

Thanks v much Paul, and everybody.
It maybe the wiring to the old marlec (which I'm using again) isn't routed via the VSR.
But I now have plan.
When I'm next on board I will check and re route if required.

Just to confirm, the VSR senses the charging input coming in and automatically Bridges all the battery banks, auto disconnecting them when the incoming charge stops...?

Just to be clear on a couple of points:

Do you have the BEP VSR fitted ?

Do you intend to fix the wind gen and continue using it ?

 

[stu9000]

I don't intend to use the wind gen.
Im pretty sure the VSR battery switch pictured in post 1 is the same as the one I have.

Based on Paul and Vics sage advice I plan to use the new victron mppt wired to engine starter battery as first priority.
I'm assuming the battery switch will automatically witch the solar charge current to top up the leisure batteries.

I need to get on board to confirm the wiring. I'll post on here.
Thanks all.

 

[VicS]

I don't intend to use the wind gen. Im pretty sure the VSR battery switch pictured in post 1 is the same as the one I have.
Based on Paul and Vics sage advice I plan to use the new victron mppt wired to engine starter battery as first priority.
I'm assuming the battery switch will automatically witch the solar charge current to top up the leisure batteries.
I need to get on board to confirm the wiring. I'll post on here.
Thanks all.

As supplied and if connected as shown in the BEP catalog :-
One of red switches should connect or disconnect the engine to or from the starter battery bank. DO NOT switch this one "Off" while the engine is running or you will blow the diodes in the alternator.
The other should connect or disconnect the services panel to or from the house battery bank.
They should be labelled.

The yellow switch should connect the engine start battery bank in parallel with the house battery bank for emergency starting if the engine battery is discharged or failing. Normally this switch should remain "Off"

The VSR is connected directly between the batteries . When the engine is started the start battery bank will begin to recharge first. When the voltage reaches 13.2 volts the VSR will operate to also connect the house battery bank. The starter batteries and the house batteries will then charge simultaneously.

If you wire your solar charging to the engine start battery bank it will charge the starter battery first . As above the VSR will close to connect the house battery when the volts rise above 13.2 . This will happen even when the red switches are "off"

( You could wire the solar charging to the house battery bank so that it charges first, the VSR connecting the start battery when the volts reaches 13.2)

The VSR disconnects when the volts fall below 12.7 volts

Details of the BEP switch cluster can be found in the 2020 BEP Catalog

Both Paul and I can suggest an improvement in the way the BEP switches are interconnected and perhaps to the way in which the alternator output is connected but I am not going to at this stage for fear of confusing things.

 

[Pete7]

If you wire your solar charging to the engine start battery bank it will charge the starter battery first . As above the VSR will close to connect the house battery when the volts rise above 13.2 . This will happen even when the red switches are "off"

( You could wire the solar charging to the house battery bank so that it charges first, the VSR connecting the start battery when the volts reaches 13.2)

This is the way we initially set up our solar via the BEP switches and indeed in the instructions with the switches recommends this.

However, in practise there is a problem. If the house batteries are discharged what happens is the solar charges up the engine start battery and the rise in voltage closes the VSR to connect the engine battery to the house bank, with a clunk. The deeply discharged house batteries then pull down the voltage for a couple of minutes and the VSR opens with another clunk. The solar then charges up the engine battery quickly for the whole process to start again. The clunking noise every couple on minutes could be heard throughout the boat and was really annoying. The solution was to move the wires from the MPPT to new bus bars for the house batteries and have them permanently connected (and fused). Problem solved, silence restored.

Stu, there is also a Victron widget which measures battery voltage and temperature and transmits their MPPTs. So if the batteries are located in a different place from the MPPT like a cold bilge and the MPPT is in the saloon or cabin, the MPPT will make adjustments for the temperature. We have seen the battery voltage adjusted up from the set point of 14.8v for flooded lead acid to 15.01v due to the cold temperatures during the winter which is useful and automatic. Conversely when we motored across the Solent on the way home over Christmas the temperature was 8'c when we started, but the engine space and the batteries rose to 18'c after hours which was surprising and again the MPPT cut the voltage down to take into account the battery temperature. What I don't know is if the battery temperature widget will work with the Blue Solar MPPTs, ours is the Smart Solar type with blue tooth, used to connect the temperature widget to the MPPT. You may need the extra blue tooth dongle for the Blue Solar MPPT. I think its worth doing to maximise and protect the batteries from over or under charging.

Smart Battery Sense - Victron Energy

 

[PaulRainbow]

I don't intend to use the wind gen.
Im pretty sure the VSR battery switch pictured in post 1 is the same as the one I have.

Based on Paul and Vics sage advice I plan to use the new victron mppt wired to engine starter battery as first priority.
I'm assuming the battery switch will automatically witch the solar charge current to top up the leisure batteries.

I need to get on board to confirm the wiring. I'll post on here.
Thanks all.

Vic and Pete have both posted some good information, so i'll just add a couple of points.

Some VSR manufacturers make a big deal of "battery priority", telling us how their VSR will prioritise this battery or that battery. In reality, this prioritising has a minimal effect, the VSR does not wait for any particular bank to be charged, it only waits for the terminal voltage to rise to a particular voltage (as Vic describes). The terminal voltage will mostly be the output voltage of the charging source, so the VSR will actually close in a short time.

I would connect the solar controller to the domestic bank. The controller should be fitted as close to the batteries as possible, the greatest affects of voltage drop is between the controller and the batteries, so short, fat cables. The wind gen may have been wired with cables that are not big enough for the solar output. Fit a fuse close to the batteries. If it is more convenient to connect the controller to the isolator switch, that's fine too, your fuse goes here too.

 

[PaulRainbow]

For anyone using the BEP switch cluster, there is (in my opinion) an error in the way the yellow emergency switch is connected, as touched on By Vic in post #15

The terminals of the yellow switch are connect to the battery terminals of each of the isolator switches. So, your engine battery won't start the engine, you turn the yellow switch to on, it links the start battery to the domestic bank and your engine starts. Great stuff !

How about if there is a problem with the engine battery, as opposed to it just being slightly discharged, or on its last legs ? When you turn the switch on, the faulty battery could mean that the engine still won't start, it could also mean that the dead engine battery is sucking as much power from the domestic bank as it can.

There are other types of failure where you might want to isolate one battery bank and use the other to power the good bank by turning the emergency switch on. With the BEP connection method, this cannot be done.

A better way of connecting the yellow emergency switch is to connect it to the load terminals of the other two switches. This simply means removing the BEP link and fitting two short cables from the yellow switches to the load terminals of the two isolators.

 

[VicS]

For anyone using the BEP switch cluster, ...............................

A better way of connecting the yellow emergency switch is to connect it to the load terminals of the other two switches. This simply means removing the BEP link and fitting two short cables from the yellow switches to the load terminals of the two isolators.

Alternatively leave the links in place and swap the other wiring between A and B and between C and D like this:
( I have also added a start battery fuse)

 

[PaulRainbow]

Alternatively leave the links in place and swap the other wiring between A and B and between C and D like this:
( I have also added a start battery fuse)

Yes, that's a good idea, saves making cables.