Parallel Morningstar MPPT CC

New on this board and will post some pics of my project this week but here's my first question for you guys.

I'd like to have a CC output of 100 amps. I have a TS 60 MPPT CC already and would like to know if I could parallel it with a TS 45 MPPT CC and have the both of them work and communicate with each other to provide the 100 amp output?

Thanks so kindly in advance,

Cee
«1

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    New on this board and will post some pics of my project this week but here's my first question for you guys.

    I'd like to have a CC output of 100 amps. I have a TS 60 MPPT CC already and would like to know if I could parallel it with a TS 45 MPPT CC and have the both of them work and communicate with each other to provide the 100 amp output?

    Thanks so kindly in advance,

    Cee

    Since you can parallel dissimilar charge controllers and have them work two of the same type certainly should. In fact they'd work very well together. Not "communicate" exactly (I'm not sure what MS's protocol is on that but it really isn't necessary), but since they both have the same functions and can be set at the same Voltages and get the same temp data there should be no problem using the two in tandem. Each will put out up to its maximum possible based on what it 'sees' as battery Voltage.

    The only ones that do better would be the MidNite Classic line utilizing the "follow me" function.
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC

    Thanks Coot (if you don't mind me calling you that) for the reply.

    I was hoping to use a common bus on the input and output sides to 'gang the to Cc's together, so too speak. I dont's have the room for the Midnight Classic and already have the TS-60-MPPT.

    I also wanted to discuss the array configuration as I wanted to use five 250 watt panels as six is just pushing it for the roof area I have available.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    Thanks Coot (if you don't mind me calling you that) for the reply.

    No, I don't mind. I'm often called worse things. :D
    I was hoping to use a common bus on the input and output sides to 'gang the to Cc's together, so too speak. I dont's have the room for the Midnight Classic and already have the TS-60-MPPT.

    Okay the output of the two controllers will be common. The input must not be. You put some of the panels on one controller, some on the other. Because of the circuitry inside them if you connect the inputs in parallel it could cause failure of either or both. Fortunately it isn't necessary.
    I also wanted to discuss the array configuration as I wanted to use five 250 watt panels as six is just pushing it for the roof area I have available.

    Making some assumptions: System is 12 Volt? Panels are 30 Vmp?
    The 60 Amp controller could handle up to about 900 Watts on it, the 45 Amp one about 700. If we divide by 250 we get three on the 60 Amp controller and two on the 45 for five panels total. Unfortunately this does not allow for any panels being in series, but with a 30 Vmp to 12 V system ratio that's not a problem. (If it were a 24 Volt system it would be, because you'd need two of the panels in series to have sufficient charging Voltage.)
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    I was hoping to use a common bus on the input and output sides to 'gang the to Cc's together, so too speak.

    No! That won't work. One solar array per controller. --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    I also wanted to discuss the array configuration as I wanted to use five 250 watt panels as six is just pushing it for the roof area I have available.

    OTOH all of those panels will run on one controller at 24v bat. Thats a way better configuration than pushing 100amps around at 12v.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    No, I don't mind. I'm often called worse things. :D

    Making some assumptions: System is 12 Volt? Panels are 30 Vmp?
    The 60 Amp controller could handle up to about 900 Watts on it, the 45 Amp one about 700. If we divide by 250 we get three on the 60 Amp controller and two on the 45 for five panels total. Unfortunately this does not allow for any panels being in series, but with a 30 Vmp to 12 V system ratio that's not a problem. (If it were a 24 Volt system it would be, because you'd need two of the panels in series to have sufficient charging Voltage.)

    Coot, Yes, it's a 12VDC system. As for the panels, I have yet to buy them and that's why I'm here. I'd like to figure out what to buy.

    I've already purchased and installed the TS-60-MPPT. I was planning on an 800 watt array but my thinking has changed and I'm now in the +/-1.2KW school of thought.

    You mentioned spliting up the panels, three on the 60 amp CC and two on the 45 amp CC and that would work for me. I could use a common bus on the output side of the CC's

    BTW this is a mobile application, it's a custom built ToyHauler that I'm setting up for Boondocking, here's a pic of the space I have for the CC's The wiring to the right is temporary as I was just seeing if the wiring scheme I came up with (reverse polarity relays) would work. It will be relocated to another area within the load center.

    I really appreciate the help,

    Cee
  • mike95490mike95490 Solar Expert Posts: 8,614 ✭✭✭✭✭
    Re: Parallel Morningstar MPPT CC

    you may really want to consider moving to a 24V system, with as much power as you are setting up for. 12V is nice when everything else runs off it, but the issues with 00 wire and needing a 2nd charge controller, maybe you should balance the cost of 2nd controller to the convenience of using existing 12v gear.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    mike95490 wrote: »
    you may really want to consider moving to a 24V system, with as much power as you are setting up for. 12V is nice when everything else runs off it, but the issues with 00 wire and needing a 2nd charge controller, maybe you should balance the cost of 2nd controller to the convenience of using existing 12v gear.

    Mike, I'm way too far down the 12VDC road to turn around at this point. The battery bank has already been completed, most of the compentents have been purchased and installed and yes, I've been kicking myself in the head for quite some time now about not rolling with 24VDC from the gate.

    How's that saying go??....hide sight is 20/20! :cry:
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC

    Hey guys, would something like this work for me?

    Voltage Maximum Power 31.5
    Current Maximum Power 8.58
    Voltage Open Circuit 38.5
    Current Short Circuit 9.17

    These are 270 watt panels.........

    Would I be safe in the assumption that I would fuse (circuit breaker) the panels indivdually at 10 amps?

    Again, thanks for helping out,

    Cee
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    Hey guys, would something like this work for me?

    Voltage Maximum Power 31.5
    Current Maximum Power 8.58
    Voltage Open Circuit 38.5
    Current Short Circuit 9.17

    These are 270 watt panels.........

    Would I be safe in the assumption that I would fuse (circuit breaker) the panels indivdually at 10 amps?

    Again, thanks for helping out,

    Cee

    Not much different from the other panels: three on a 60 Amp MPPT controller; 810 Watts yielding about 52 Amps to a 12 Volt system. Two on a 45 Amp MPPT controller giving another 26 Amps, total 78 Amps.

    If you had some around 220 Watts then you'd get four on the 60 Amp for 56 Amps out and three on the 45 Amp for 42 Amps out totaling 98 Amps.
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC

    Coot, thanks again!

    Seven panels, that's a lot of roof space......maybe roof space that I don't have. I'll need to do a little layout to see just how much real estate I do have.
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    Not much different from the other panels: three on a 60 Amp MPPT controller; 810 Watts yielding about 52 Amps to a 12 Volt system. Two on a 45 Amp MPPT controller giving another 26 Amps, total 78 Amps.

    If you had some around 220 Watts then you'd get four on the 60 Amp for 56 Amps out and three on the 45 Amp for 42 Amps out totaling 98 Amps.

    Cariboo:

    Would the wiring logic be parallel?

    I'm still trying to figure out how you've come to the above totals as there's no simple division. Could you enlighten me as to the math involved or could you point me to a thread that defines this logic?

    I'd greatly appreciate it, thanks so kindly,

    Cee

    BTW, maybe I should have started this thread in the Solar Beginners Club sub-forum. Feel free to move it over there if it would be better servred.
  • BB.BB. Super Moderators, Administrators Posts: 30,055 admin
    Re: Parallel Morningstar MPPT CC

    With MPPT controllers they are "Constant Power" devices... If you put 880 Watts in, you get 880 Watts out (really ~95% of the input power out)... They are sort of like DC version of an AC variable transformer (that is the switching power supply inside the controller).

    I.e., Power In * 0.95 = Power Out
    Vmp-array*Imp-array * 0.77 panel+controller derating = Vbatt-charging * Ibatt-charging

    Anyway, if I followed the discussion, here is how a piece of the math works (note I/we tend to use 0.77 to account for ~81% Vmp-panel in normal/warm operations and ~95% MPPT controller efficiency):

    880 Watts * 0.77 panel+controller derating * 1/14.5 volts charging = 46.7 amps to battery bank
    880 Watts * 0.77 panel+controller derating * 1/12.1 volts charging = 56.5 amps to battery bank

    Notice that (I think) Marc "Cariboocoot" used 12 volts for the battery bank... I used 14.5 volts (assuming the controller spends much of its time at higher voltages when charging (I tend to be a bit more conservative or "pessimistic" in my calculations)... Either way, the end results is similar.

    The MPPT can take a "wide range" of input Vmp-array voltages and Imp-array currents and efficiently down convert it to the lower voltage/higher current needed by the battery bank. It is sort of like the automatic transmission for a car (for another analogy).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC

    Okay, starting to see the math here now so I'm back to the wiring logic.

    If I'm going to use 270 watt panels and have a 3 / 2 combination, again is the wiring going to be parallel or series?
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    Mike, I'm way too far down the 12VDC road to turn around at this point. The battery bank has already been completed, most of the components have been purchased and installed and yes, I've been kicking myself in the head for quite some time now about not rolling with 24VDC from the gate.

    How's that saying go??....hide sight is 20/20! :cry:

    So you are in the 12 volt hole... and you plan to dig in deeper? What do you have for batteries? Perhaps they can be rewired for 24 volts. If you go to 24 volts you will need a different inverter, but you will NOT need an additional charge controller.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Parallel Morningstar MPPT CC
    vtmaps wrote: »
    So you are in the 12 volt hole... and you plan to dig in deeper? What do you have for batteries? Perhaps they can be rewired for 24 volts. If you go to 24 volts you will need a different inverter, but you will NOT need an additional charge controller.

    --vtMaps

    RV application: the 12 Volt is necessary for the numerous 12 Volt devices. It's a shame, but there it is. In such a case space limitations often eliminate the possibility of having a 24 Volt system as well as the 12 Volt.
  • BB.BB. Super Moderators, Administrators Posts: 30,055 admin
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    Okay, starting to see the math here now so I'm back to the wiring logic.

    If I'm going to use 270 watt panels and have a 3 / 2 combination, again is the wiring going to be parallel or series?

    Can you be a bit more clear here?

    Are you talking about placing the solar panels in series or parallel? And if so, we need more information for an exact answer. The numbers of panels, panel Vmp/Imp and the charge controller brand model you are looking at (at least). Also, confirm you are still looking at a 12 volt battery bank (or other bank voltage).

    There is a lot of configuration issues to juggle.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    Okay, starting to see the math here now so I'm back to the wiring logic.

    If I'm going to use 270 watt panels and have a 3 / 2 combination, again is the wiring going to be parallel or series?


    The math is a bit of back-and-forth checking.
    For example: 60 Amps (maximum output of controller) * 12 Volts (minimum system Voltage where current is likely to be highest) = 720 Watts / 0.77 efficiency average = 935 Watt array likely largest.

    Divide the 935 Watts by a panel size such as 270 Watts and round to the nearest whole number: 3 panels. Multiply that back out and get an 810 Watt array which would produce (810 * 0.77 / 12) 52 Amps. Try again until you find some combination of Wattage and number of panels that works out to maximum current potential to make full use of the controller.

    It's actually 230 Watts that comes closest. But that doesn't mean you'll find 230 Watt panels, so panel availability also has to be taken into account.
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    vtmaps wrote: »
    So you are in the 12 volt hole... and you plan to dig in deeper? What do you have for batteries? Perhaps they can be rewired for 24 volts. If you go to 24 volts you will need a different inverter, but you will NOT need an additional charge controller.

    --vtMaps

    vtMaps:

    As I said before, I'm way to far down this road to turn back at this point. Here's a few pixs that I'm sure will explain just how far down this path I am.....

    Buying another CC and the associated wiring is the cheap way out!
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    The math is a bit of back-and-forth checking.
    For example: 60 Amps (maximum output of controller) * 12 Volts (minimum system Voltage where current is likely to be highest) = 720 Watts / 0.77 efficiency average = 935 Watt array likely largest.

    Divide the 935 Watts by a panel size such as 270 Watts and round to the nearest whole number: 3 panels. Multiply that back out and get an 810 Watt array which would produce (810 * 0.77 / 12) 52 Amps. Try again until you find some combination of Wattage and number of panels that works out to maximum current potential to make full use of the controller.

    It's actually 230 Watts that comes closest. But that doesn't mean you'll find 230 Watt panels, so panel availability also has to be taken into account.

    Cariboocoot:

    I'll get a chance to do the rooftop layout this week but I just might be able to squeeze in a sixth panel. I'd still wire three panels on each CC but the clarification I'm looking for would be how to configure that wiring. Would it/they be wired in Parallel?....or in Series?

    Thanks again,

    Cee
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    vtmaps wrote: »
    So you are in the 12 volt hole... and you plan to dig in deeper? What do you have for batteries? Perhaps they can be rewired for 24 volts. If you go to 24 volts you will need a different inverter, but you will NOT need an additional charge controller.

    --vtMaps

    Here's a top view, ten Crown 6VDC 260 AH GC2's - 5 strings and perfectly balanced, at least according to my digital multi-meter.
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Parallel Morningstar MPPT CC
    boonhauler wrote: »
    Here's a top view, ten Crown 6VDC 260 AH GC2's - 5 strings and perfectly balanced, at least according to my digital multi-meter.

    Which you measured how? If you measured voltage, then yep theyll be balanced all right. To within 0.0001V.

    The imbalance that occurs in multi string occurs in current sharing mismatch, right?
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Parallel Morningstar MPPT CC

    One of those cases where you need positive and negative bus bars for the parallel battery strings, individual string fuses, a lot of attention to detail, and good luck.

    For the panels if we are talking three per controller you should have them in parallel, as putting all in series would cause a pretty big difference between array Vmp and system Voltage decreasing efficiency. Plus since this is an RV application the parallel panels will have less loss from any passing shadows blocking part of one panel.
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    zoneblue wrote: »
    Which you measured how? If you measured voltage, then yep theyll be balanced all right. To within 0.0001V.

    The imbalance that occurs in multi string occurs in current sharing mismatch, right?

    Zoneblue:

    I used method #3 here http://www.smartgauge.co.uk/batt_con.html for the wiring logic.

    I painstakedly made every lenght of wire from the commom bus exactly the same. All the connections were made exactly the same. It took alot of research before I decided to roll with 5 series strings. If you'd like to look it over you can as I have chronicled the build here but you'll have to read through 5 or 6 pages. http://www.southbayriders.com/forums/threads/119206/page-14

    BTW, my multi meter goes out two decimal points so I'm sure it wont meet your standard.
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    One of those cases where you need positive and negative bus bars for the parallel battery strings, individual string fuses, a lot of attention to detail, and good luck.

    For the panels if we are talking three per controller you should have them in parallel, as putting all in series would cause a pretty big difference between array Vmp and system Voltage decreasing efficiency. Plus since this is an RV application the parallel panels will have less loss from any passing shadows blocking part of one panel.

    Thanks Cariboocoot, parallel it is.
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Parallel Morningstar MPPT CC

    Im afraid you may have missed the point of my wit. Batterys in parallell will by definition have identical terminal voltages. You said that your 5 strings are "perfectly balanced at least according to my digital multi-meter".

    The imbalance occurs because of subtle differences in internal resistance, and capacity. One weak cell in one battery in one string will make that entire string lag behind taking less of the charge, and over time weaken that string.

    The way to measure/monitor string balance is, as Coot says, with a current meter, during charge and discharge. (SG also.) Thats the acid test of string balance. Sorry can help it, acid test is just the right pun for the job.

    boonhauler wrote: »
    Zoneblue:

    I used method #3 here http://www.smartgauge.co.uk/batt_con.html for the wiring logic.

    I painstakedly made every lenght of wire from the commom bus exactly the same. All the connections were made exactly the same. It took alot of research before I decided to roll with 5 series strings. If you'd like to look it over you can as I have chronicled the build here but you'll have to read through 5 or 6 pages. http://www.southbayriders.com/forums/threads/119206/page-14

    BTW, my multi meter goes out two decimal points so I'm sure it wont meet your standard.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Parallel Morningstar MPPT CC
    I have chronicled the build here but you'll have to read through 5 or 6 pages. http://www.southbayriders.com/forums...119206/page-14

    BTW, nice write up, a right handy chap having a hoot load of fun along the way.


    Id be a little cautious with those busman breakers, they are not nearly as robust in terms of interupt rating as the carling breakers. Also the battery switch, be sure you dont switch that under any kind of load. As a rule we try to avoid those sorts of things, when theres big amps concerned. There have been reports here of molten plastic and what not. That bank will deliver some serious short circuit currents, so good reason to choose industrial grade products. Check these out:
    http://www.solar-electric.com/mnedc175.html
    http://www.solar-electric.com/mndc125.html

    Small peice of mind.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    zoneblue wrote: »
    Im afraid you may have missed the point of my wit. Batterys in parallell will by definition have identical terminal voltages. You said that your 5 strings are "perfectly balanced at least according to my digital multi-meter".

    The imbalance occurs because of subtle differences in internal resistance, and capacity. One weak cell in one battery in one string will make that entire string lag behind taking less of the charge, and over time weaken that string.

    The way to measure/monitor string balance is, as Coot says, with a current meter, during charge and discharge. (SG also.) Thats the acid test of string balance. Sorry can help it, acid test is just the right pun for the job.

    ZoneBlue:

    If you follow this link towards the bottom of the page in post #279 I posted two worksheets that I've generated to track SG. http://www.southbayriders.com/forums/threads/119206/page-19

    I've had discrepancies with SG v Voltage in regards to what's a 100% SOC. I've come to the conclusion that I really need to be watching the SG more than Voltage.

    BTW, could you recommend a decent Hydrometer (link would be cool). I'd like to buy a Fluke 325 but money doesn't grow on trees where I live and I still have a long way to go to finish my project.

    Again, as I stated in the opening posts, if I had it to do again I sure would do things differently with a 24 VDC system being at the heart of things.
  • boonhaulerboonhauler Solar Expert Posts: 35
    Re: Parallel Morningstar MPPT CC
    zoneblue wrote: »
    BTW, nice write up, a right handy chap having a hoot load of fun along the way.


    Id be a little cautious with those busman breakers, they are not nearly as robust in terms of interupt rating as the carling breakers. Also the battery switch, be sure you dont switch that under any kind of load. As a rule we try to avoid those sorts of things, when theres big amps concerned. There have been reports here of molten plastic and what not. That bank will deliver some serious short circuit currents, so good reason to choose industrial grade products. Check these out:
    http://www.solar-electric.com/mnedc175.html
    http://www.solar-electric.com/mndc125.html

    Small peice of mind.

    Thanks, I saw the Busman breakers as providing two functions, 1) Over-current protection and 2) System dis-connects. As for the Blue Sea battery switch, a dis-connect for the inverter and I'd never play around with it under loaded conditions.

    The real purpose of the inverter disconnect is to provide a conveinent way to drop the inverter parasitic draw when shutdown. I liked the compact size of the Busman breakers and as you can see there's just not a whole lot of available space in the load center.

    Now that I'm visiting this site I'm learning more and more each day, again, hindsight is always 20/20.

    The Magnum 2812 will do all the heavy lifting when needed but I have a smaller 800 watt inverter that will power the entertainment center that I'm sure will do most of the work.
  • 65DegN65DegN Solar Expert Posts: 106 ✭✭✭✭
    Re: Parallel Morningstar MPPT CC

    Really about the only thing in your way to changing system voltage, it appears, is the inverter. I would sell it and get something in 24V and run almost everything on 120 VAC. JMO
Sign In or Register to comment.