Contention Between Victron 100/30 and Morningstar PWM?

[jpendoley]

I just added a 200watts of solar to my bimini connected to a Victrom 100/20 MPPT controller. There is prexisting 160 watt array on my davits that is connected to a Morningstar Prostar 15M. When I flip on the Victron's breaker the current the Prostar is producing begins to drop. They are both wired to the same battery bank and the same posts (four 6Volt batts connected in parallel and series to yield 12volts and 400 amp capacity). Wjhats going on here? By adding the 200 watt panels I somehow am throttling the 160 watts on the davits...

[wholybee]

The interaction is complex, but the first question, what is the state of charge of the batteries at the time this happens? What is the total amount of charge current you are seeing? The most likely thing that is happening is that the battery is limiting the rate of charge, and so the current the battery will accept is being divided between the 2 controllers.

There can also be interaction based on the charge parameters of each controller. If you post all of the parameters of how the 2 controllers are programmed, maybe someone can find an issue.

[noelex 77]

It is likely that the solar controllers were just regulating the current to appropriately charge the battery. Try turning on a high load. The solar output should adjust to deliver the maximum output possible under the conditions.

[jpendoley]

Thanks Warren, the bank was high probably 12.8. You may be right because if I switch off the MPPT controller the PWM controller climbs to 8-9 amps but drops down to 2.5 A as soon as the mppt controller begins pushing in about 6A of current.
I think I will put a load on the bank to see how they work together with a battery that's not so full.

[mlydon]

Your problem is that the controllers interfere with each other. They each ‘see’ the others output as battery voltage, and reduce charge. “Gee, the battery is already at 13.4 - it’s full, so I’ll just float it….”

Best to run all your panels to one controller, which will manage charging your batteries. Btw - you should upgrade to the 100/30 controller to handle your power - it will charge at 30amps.

Others may have different insights, but I have a balmar 250 amp alternator and a victron multiplus 120amp charger. I do NOT get their combined output going into my bank, for the same reason.

AMatt

[smac999]

Does the morning star have user adjustable settings? You want them both set to the exact same voltages. Which they may not be.

[jpendoley]

The morningstar does not have customizable voltages-just FLA or AGM or I’m not sure what else. . It is set for FLA but I don’t know if that is identicle to the Victrons setting. Today the Victron MPPT said the battery bank was at float and was sending no current to the bank BUT the PWM was putting five amp in. Any additional thoughts?

[jpendoley]

So the Morningstar PWM controller now sees the same voltage as the Victron 100/20 MPPT and they were both in float-so far so good.

Today I added a second 200 watt array and a second 100/20 MPPT also run to the same 400 amp 12 v FLA bank. This new controller is connected to the other pair of battery posts in the 400 amp bank. It was in absorbtion even though the other two controllers were in float. The bank is wired in parallel and series ((four 6V FLAs). Is it safe to assume this is a minor variance due to cable length differences? If the mppts read voltage via resistance in the bank different attachment points would show different resistance depending where in the bank they are attached-is that true? The bank is new, battery cables are new, the lengths are short and the battery cables are the correct gauge (#1 gauge battery cable. Dont want to cook my new batteries.

One other related question: the victron mppts are set to 12 volt deep cycle gel charging profiles. This is one of four profiles that come standard. There is no FLA profile (I'd have to add a custom one). Are Gel and FLA charging profiles the same?

[wholybee]

Originally Posted by jpendoley

The morningstar does not have customizable voltages-just FLA or AGM or I’m not sure what else. . It is set for FLA but I don’t know if that is identicle to the Victrons setting. Today the Victron MPPT said the battery bank was at float and was sending no current to the bank BUT the PWM was putting five amp in. Any additional thoughts?

If the settings of multiple controllers do not match (and sometimes even if they do match) this can happen. But it doesn't make any difference, because it happens near the end of the charge when the battery won't accept all the current if all controllers were producing anyway. So, if you got both the controllers working, they would each have about 2.5A instead of only one at 5A.

It sounds to me like it is working now. Also, I disagree with the idea to put everything on one controller. The BEST installation is every controller on it's own controller. And if you do that with Victron Smart controllers, they will talk to each other via bluetooth and change stages together.

[jpendoley]

Wholy, that’s a great answer and matches what I’m seeing on the controllers, thank you! Yeah, the price of charge controllers has come down to the point where it really is a simple decision to have dedicated controllers to dedicated array

[NorthCoastJoe]

I have two arrays and two matching Victron 100/50 MPPT controllers. I never had a problem. One array is flexible panels and the other Rigid panels.
On the boat it's all Victron, but on my home system it is Morningstar. I would not mix brands of solar controllers. I use both brands and like them both.

[barnakiel]

I had a Victron 20A which acted in a strange way - it was OK as long as I left it well alone. Then one day I connected to it from Android App - at which point the App displayed "you must update the firmware" warning ... and the unit stopped charging.


a TRUE bummer and maybe Victron has fixed this by now, or maybe NOT ?


If we were offshore, there would have been NO way to solve this. The firmware is updated via the App, after downloading the new version from the Internet.


....




psssssssssssssssssssss


gassssssssssssssssssssss


As I have said. Perhaps Victron has solved this bug ... perhaps not.


cheers,
barnakiel


PS I did keep the regulator and it works good.

[CrispyCringle]

Sounds like the two controllers are not matched as to when they go from bulk to absorption to float. You probably dont want to do it, but I would ditch the Morningstar and get another Victron unit. The Victron's will talk to each other and one becomes the Master. That way, they are always in sync with the charge stage.