Victron BlueSolar charge controller

[socaldmax]

Originally Posted by mikedefieslife

Multiple Victrons have peaked my interest now. I note that is a large display panel available, at a reasonably large cost, but this does away with the need for a module on each controller.

Anyway, with multiple charge controllers do you wire the both the positives and both the negatives from the controllers together so you only have a single positive and negative run down to the battery bank? Or do you just attach each one to a different pos/neg terminal within the bank?

I know you didn't ask this question, but for cost and power efficiency sake, I've installed mostly 20A MPPT controllers dedicated to a single roughly 300w panel and then scaled it up from there. If the customer wanted 1200w, then we installed 4 panels and 4 controllers, unless the customer absolutely insisted on a single or pair of 60A controllers.

To answer your question, some people decide to put in a junction box below deck with double pole switches (or CBs) for each solar controller. This is where the individual inputs can be combined after the switches to a bus bar and a larger cable used to connect to the main battery bank bus bar. It's always better to keep the clutter off of the battery posts.

[john61ct]

Originally Posted by SailsTeam

The plan was to hook the alternator up to charge the house bank not the starter batteries then use a very small solar panel to keep the starter batteries charged.

Great idea on the Alt to House, but IMO a little Echo Charger on Starter would be better.

Originally Posted by SailsTeam

the Blue Sea ACR has a VERY high cut in voltage which makes it nearly worthless with a small 200w solar setup

Lower amps has nothing to do with voltage, all charge sources should usually be set the same, as per your bank mfg specs.

Blue Sea usually ​closes (combines) when 13.0V for 2 minutes, ​opens (isolates) when 12.75V for 30 seconds.

There are also robust devices with adjustable setpoints.

Originally Posted by SailsTeam

Combining dead batteries with good house batteries is a terrible idea. What were they thinking putting these switches in boats?

Just get a 1-2 switch for self jumping: no All/Both, no Off, make before break, big amps.


search for

"Single Circuit ON-OFF" "blue sea" amps

[mitiempo]

Originally Posted by SailsTeam

The Blue Sea ACR has a VERY high cut in voltage which makes it nearly worthless with a small 200w solar setup. It is mostly for alternator charging. Either way that could be used with the system I describe.

You are incorrect. The Blue Seas ACR will combine at 13.6 volts for 30 seconds or 13 volts for 90 seconds. Even it the battery is fully charged and on float the ACR will combine in 90 seconds. They are used in thousands of boats and the charging source is not important. Whether it is an alternator, solar, wind generator, or shore power charger it is voltage that causes the ACR to combine.

If the voltage is too low for the ACR to combine it is also too low to charge.

[foggysail]

Originally Posted by socaldmax

I know you didn't ask this question, but for cost and power efficiency sake, I've installed mostly 20A MPPT controllers dedicated to a single roughly 300w panel and then scaled it up from there. If the customer wanted 1200w, then we installed 4 panels and 4 controllers, unless the customer absolutely insisted on a single or pair of 60A controllers.

That is a different approach from the normal. The system wiring and controller mounting must be a dog with each controller requiring battery connections along with the a panel's connection plus fuses. And no disconnects between the panels and the controllers?

[socaldmax]

Originally Posted by foggysail

That is a different approach from the normal. The system wiring and controller mounting must be a dog with each controller requiring battery connections along with the a panel's connection plus fuses. And no disconnects between the panels and the controllers?

How do you know what "the normal" is?

What does a dog have to do with this? I realize it's probably a typo, but I'm at a loss as to the correct word you meant.

Why put in disconnects between the panels and the controllers? The panels can sit there shorted all day, if they produce enough current to burn up the wires then you selected the wrong size of the wrong quality of wire. Trying to protect the controller from shorted inputs? It's probably damaged long before you can flip that switch. How did the wire get shorted? Chafing? Bad job of installing the wires. Want to disconnect the solar panel? Just unplug the MC4 connector. Want to shut off the panel before disconnecting power? Simply shade one or more cells on the panel. Want to protect the solar panel from a shorted solar controller? No problem, shorted out doesn't hurt solar panels.

However, the side with the battery connected to it...

well it has the entire capacity of the battery bank behind it if one of the solar controllers decides to be current sink instead of a current source.

[john61ct]

Originally Posted by foggysail

That is a different approach from the normal.

Actually other than possibly being more expensive, one controller per (small group or single) panel is ideal against shading and quite common on boats.

Looking at Victron pricing, you're really not even paying much, if any, cost premium, those 75/15s can get down to $75 delivered!

And a KISS effective wiring scheme only needs to be worked out once.

[foggysail]

Originally Posted by socaldmax

How do you know what "the normal" is?

What does a dog have to do with this? I realize it's probably a typo, but I'm at a loss as to the correct word you meant.

Why put in disconnects between the panels and the controllers? The panels can sit there shorted all day, if they produce enough current to burn up the wires then you selected the wrong size of the wrong quality of wire. Trying to protect the controller from shorted inputs? It's probably damaged long before you can flip that switch. How did the wire get shorted? Chafing? Bad job of installing the wires. Want to disconnect the solar panel? Just unplug the MC4 connector. Want to shut off the panel before disconnecting power? Simply shade one or more cells on the panel. Want to protect the solar panel from a shorted solar controller? No problem, shorted out doesn't hurt solar panels.

However, the side with the battery connected to it...

well it has the entire capacity of the battery bank behind it if one of the solar controllers decides to be current sink instead of a current source.

What is normal? From Webster's New World Dictionary:

"Conforming with or constituting an accepted standard, model especially corresponding to median or average of a large group!"

Stacking individual controllers does not correspond to the the median, or average of a large group!

What did I mean calling your approach a dog??? Running multiple battery wires, finding real estate in a boat to install multiple controllers, making things difficult both wire, install and service.

Why install disconnects? Surely you must be joking or you just don't know any better. Disconnects protect both against equipment failures plus minimize personnel hazards when servicing the equipment. And yeah, POOP happens.

Another reason to avoid installing a controller with each panel especially for MPPT applications is to take advantage of placing panels in series that result in a higher Vpp that will minimize voltage losses in the panel distribution wiring. In basic words, allows small gage wires to be economically used.

[foggysail]

Originally Posted by john61ct

Actually other than possibly being more expensive, one controller per (small group or single) panel is ideal against shading and quite common on boats.

Looking at Victron pricing, you're really not even paying much, if any, cost premium, those 75/15s can get down to $75 delivered!

And a KISS effective wiring scheme only needs to be worked out once.

KISS? Multiple, multiple and multiple of everything involved in an installation is far from keeping things simple

[john61ct]

I never said one per panel, if nominal 12V panels are used then strings of two are great for MPPT.

The 75/15s take up little space, most larger-amp controllers take a lot.

Most boats suffer from shading issues.

Neat wiring is not rocket science.

In the end do what you like.

[foggysail]

Originally Posted by john61ct

I never said one per panel, if nominal 12V panels are used then strings of two are great for MPPT.

The 75/15s take up little space, most larger-amp controllers take a lot.

Most boats suffer from shading issues.

Neat wiring is not rocket science.

In the end do what you like.

Well thanks John! Of course I always attempt to do what is expedient for the tasks I encounter. Sorry if I misunderstood where you stated earlier

" Actually other than possibly being more expensive, one controller per (small group or single) panel is ideal"

Sure, if you only have a single panel and maybe you meant that, a single controller is a must.

But back to wiring.... whether there is a single controller for a bunch of panels or a controller /panel neat wiring will make servicing the installation easier. But neat wiring should not be the justification to use a controller/panel in multiple panel installations.

EDIT: Whenever an MPPT controller is used in lieu of the old standard pulse width modulation style controllers, one is wise to take advantage of placing multiple panels in series up to the voltage limits of the controller. Doing so relaxes the voltage losses in the panel distribution circuit and allows smaller gage wiring.

Yes there are shading issues.....there are always shading issues but panel internal diodes are there to minimize that problem.

[john61ct]

Originally Posted by foggysail

Sorry if I misunderstood where you stated earlier

" Actually other than possibly being more expensive, one controller per (small group or single) panel is ideal"

Sure, if you only have a single panel and maybe you meant that, a single controller is a must.

Hard for me to tell if you are being sarcastic, but yes I did explicitly state "a small group" to cover low-volt panels for MPPT efficiency. But higher-voltage single panels are getting to be very common these days, and often at a much lower cost per watt.

Originally Posted by foggysail

But neat wiring should not be the justification to use a controller/panel in multiple panel installations

Yes that would be silly, as would choosing neat simplicity over getting maximum performance from the overall system.

Same with series wiring just to reduce wiring costs, shading problems go up exponentially.

Originally Posted by foggysail

Yes there are shading issues.....there are always shading issues but panel internal diodes are there to minimize that problem.

Which barely help at all, certainly not nearly as much as using a larger number of small controllers.

Do some real-world testing when you get a chance, really does make a significant difference.

[foggysail]

Originally Posted by john61ct

Hard for me to tell if you are being sarcastic, but yes I did explicitly state "a small group" to cover low-volt panels for MPPT efficiency. But higher-voltage single panels are getting to be very common these days, and often at a much lower cost per watt.

Yes that would be silly, as would choosing neat simplicity over getting maximum performance from the overall system.

Same with series wiring just to reduce wiring costs, shading problems go up exponentially.

Which barely help at all, certainly not nearly as much as using a larger number of small controllers.

Do some real-world testing when you get a chance, really does make a significant difference.

John, I disagree with you on the series wiring but again, there are various circumstances that change the value both positively and negatively on placing panels in series. You correctly mentioned that there is becoming an abundance of newer, higher voltage panels in the marketplace. They of course demand an MPPT because the old PWM styles are basically switches. By that I mean the panel is toggled on until a float condition is attained at which point the controller time modulates the current allowance to the batteries.

MPPTs have a minimum voltage value above that of the battery for them to function. So conditions can occur whereby a shaded non-series panel just won't work. But obviously the higher the panel voltage is, the greater the shading required for the voltage seen by the controller to be in that condition. I don't think this matters much in the older PWM stuff.

And John, I am happy with my current experience in both solar and electrical engineering.

[socaldmax]

Originally Posted by foggysail

What is normal? From Webster's New World Dictionary:

"Conforming with or constituting an accepted standard, model especially corresponding to median or average of a large group!"

Stacking individual controllers does not correspond to the the median, or average of a large group!

What did I mean calling your approach a dog??? Running multiple battery wires, finding real estate in a boat to install multiple controllers, making things difficult both wire, install and service.

Why install disconnects? Surely you must be joking or you just don't know any better. Disconnects protect both against equipment failures plus minimize personnel hazards when servicing the equipment. And yeah, POOP happens.

Another reason to avoid installing a controller with each panel especially for MPPT applications is to take advantage of placing panels in series that result in a higher Vpp that will minimize voltage losses in the panel distribution wiring. In basic words, allows small gage wires to be economically used.

If you think installing 100w panels is the norm, then I can see why you'd feel 1 controller per panel would be a lot of wire, but I clearly explained that I'm discussing 300w or larger panels, which can put out ~ 20A at full power, so even if one needed 80A of solar power, one could route 2 sets of wires through separate grommets or however you like.

Your opinions about the virtues of serial over parallel wiring don't hold up based on real world experience. Everybody claims bypass diodes are the answer to extreme power losses during partial shading, but it's very difficult to refute this video. You're welcome to try. Please explain what is wrong with their testing methodology and why it completely disagrees with your unsupported conclusions.

https://www.youtube.com/watch?v=1qD3mN8VotQ

I CLEARLY explained why I wouldn't bother installing disconnects between panel and controller, go back and read it again. Even if you install them, by the time you realize something is wrong, the damage is already done.

I suppose if you're installing 100w ~ 17v panels, one would need to run 2 in series to get ~ 34v. The 320w panels I use produce ~ 38v, that's plenty high enough to give the MPPT controller some headroom to convert that to about 20A into the battery bank.

If your primary concern is to save a few $$ by using smaller gauge wire...

more power to you. I quite often recommend larger wire than most people would use just to minimize losses to below 3% voltage drop. Sure it costs a couple dollars more, but I prefer to err on the side of minimal losses, the initial cost is only a 1 time deal.

[DotDun]

Originally Posted by socaldmax

........
Your opinions about the virtues of serial over parallel wiring don't hold up based on real world experience. Everybody claims bypass diodes are the answer to extreme power losses during partial shading, but it's very difficult to refute this video. You're welcome to try. Please explain what is wrong with their testing methodology and why it completely disagrees with your unsupported conclusions.

It's very easy to refute the video, there were no bypass diodes. Period!

[socaldmax]

Originally Posted by foggysail

MPPTs have a minimum voltage value above that of the battery for them to function. So conditions can occur whereby a shaded non-series panel just won't work. But obviously the higher the panel voltage is, the greater the shading required for the voltage seen by the controller to be in that condition. I don't think this matters much in the older PWM stuff.

Only if you're using antiquated low output, low voltage panels. Sure, 100w panels like they sold 5 - 10yrs ago put out about 17v @ Vmp, but the current crop of 320w panels are producing about 38v @ Vmp, more than twice what a series pair of 12v panels produce.

The ones who have done their homework and who can get them are using Sunpower 327w or Sunpower 435w panels for their far superior efficiency, which should be the most important factor on a small vessel with limited space. The 327w panel Vmp is 54.7V and the 435w panel Vmp is 72.9V.

Due to their unique construction technique, they don't suffer nearly as bad as regular solar panels in partial shading conditions. Quite often, their shading losses are as low as 11%.

https://www.youtube.com/watch?v=dlZSL4C0VYQ