BZ 250W/25A Solar MPPT Charge Controller

2

Comments

  • lorelec
    lorelec Solar Expert Posts: 200 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Sure, we're now using synchronous rectification and have much better semiconductors that we had even five years ago, so the electrical efficiency is going to be better. And digital control has no doubt improved the functionality and tracking efficiency of these controllers.

    There was some confusion as to how the MPPT controller worked in relation to its associated battery and PV. That's all I was expounding upon. Aside from the bells and whistles of modern controllers, we still have a very basic power supply topology that is still arranged to perform a specific function.

    Marc
  • harley4jcs
    harley4jcs Registered Users Posts: 10
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Holly Smokes.... :confused: THANKS for ALL the input :cry:

    Just kidding :D Really, Thanks for such detailed & GREAT info..
    I'm petty set on a MPPT now For Sure But with the W & S Admin post I'm even more locked up as to which one !!

    Rethinking the 12v/24v thing as well. If I understand this correctly with a MPPT I could run high V Pv array into a 12v Batt bank with no problems ?? However I'll be breaking up the bank frequently so I'll probably hook up at 24v anyway..

    I'm basically trying to just recharge Batts, not set up a permanent power supply.
    I have to many different uses & locations of the batts for a convenient single power supply..:grr

    For Uguys that have 24/48/36 v banks I'm assuming U'r inverters have a 12v out put available for all the 12v stuff ??

    Marc, I'm trying to justify the coin for one of those beauties U put together, Thanks for U'r input to this thread as well... ( have any blems or returns ?? ;) )
  • harley4jcs
    harley4jcs Registered Users Posts: 10
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Bill : Thanks so much for the Ed.. Yes , I'm tracking with you & U cleared up the issue for me very well. Thanks for such a detailed & time consuming answer to such a basic question ( for U anyways).. Much Appreciated

    If U've got more I love to read it.. :D
  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    If you are not in a big hurry, wait about 3 weeks and the new Morningstar MPPT's should (we hope) start shipping.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Its officially released as of Monday :D so the only delays would be shipping time from TW where MS products are produced

    Here is links to the documentation

    http://www.morningstarcorp.com/en/support/product.cfm?Name=TriStar%20MPPT

    It is the most efficient Mppt controller on the market, none better. Tracking is fool proof as well.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Personally, I would like to see some more test results from Marc's product, and I would like to see some more support for it, as it is designed and built on shore with local labour, which in the grand scheme of things is, I think, a good thing. (Perhaps NWAS and Marc could forge a relationship!)

    Just my opinion,

    Tony
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    FYI, All MorningStar products are Designed, field tested and supported in the USA.

    Production is in Taiwan, but that's to have a competitive priced product. It also helps for distribution as MorningStar is truly a globally sold product.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: BZ 250W/25A Solar MPPT Charge Controller

    By the way, this is Marc's MPPT controller:

    Rogue Power Tech

    If you are into electronics--Marc has options that include schematics and DYI assembly... Very interesting customer options.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • harley4jcs
    harley4jcs Registered Users Posts: 10
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Not in a BIG hurry ( but do want to wrap things up ) for this important piece of the equation..Just want the best & right product that I can afford. So in my case I won't be buying the BEST product on the market, Just don't want to buy a POJ either.. One must remember I started this post asking if the BZ was worth $109.00.. I would say the resounding answer was NO..
    Thanks for all the inputs.
  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller
    icarus wrote: »
    Personally, I would like to see some more test results from Marc's product, and I would like to see some more support for it, as it is designed and built on shore with local labour, which in the grand scheme of things is, I think, a good thing. (Perhaps NWAS and Marc could forge a relationship!)

    Just my opinion,

    Tony

    We looked at the Rogue products with an eye to carrying them a while back, but some of the documentation was a bit sparse, and there was no track record on reliability. We (and customers) have been burned in past by products that had an excessive fail rate, so anymore we do not sell products unless we have some indication of how well it is going to work beyond what is in the mfg's brochures.
  • lorelec
    lorelec Solar Expert Posts: 200 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    "It is the most efficient Mppt controller on the market, none better."

    My 3024 is slightly better over any range for which you can compare the two (since the Morningstar has a max 48v system voltage, and mine is limited to 24v -- that's where the comparison ends).


    "...but some of the documentation was a bit sparse..."

    Funny, I've had lots of positive feedback specifically on how thorough the documentation is. If you could tell me where you think it's lacking, maybe I can improve it some. I don't blame a retailer for not carrying my product, and I don't expect them to. I've had several inquiries from dealers, but due to my slim margin I'm unable to sell to them at a substantial enough discount. If I made the unit in China or Taiwan, then maybe...

    Marc
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    lorelec, If you would, please post up similar charts for 12 and 24V for your charger.

    The TS-Mppt results were obtained using a Yokogawa power analyzer that was just a lab listed certified and calibrated for the efficiency tests to be published in the manual.

    One would need the ability to accurately to find sub single watt differences to have higher efficiency than the TS-MPPT, appropriate equipment to make those measurements is an expensive undertaking, this is what was used for the TS-MPPT

    http://tmi.yokogawa.com/products/digital-power-analyzers/digital-power-analyzers/wt1600-digital-power-meter/ was the analyzer used for the charts in the manual.

    The TS-MPPT is 150V, FCC class B compliant and CE listed controller and our testing indicates that no other controllers in this class have better performance or efficiency

    SG
  • harley4jcs
    harley4jcs Registered Users Posts: 10
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Marc, I'm trying to justify the coin for one of those beauties U put together, Thanks for U'r input to this thread as well... ( have any blems or returns ?? )
  • lorelec
    lorelec Solar Expert Posts: 200 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    SG,

    The Yokogawa is a nice piece of equipment, and I’d love to be able to afford one, but I think it’s a little overkill for this application (especially at ~$15k!). We’re not even primarily concerned with absolute accuracy – more with the relative accuracy between measurements of input and output. I use a pair of matched Empro shunts with a couple of Agilent 5.5 digit meters. I then use a Sharp calculator to perform calculations. My method might be a little less accurate, but even if that’s the case, the efficiency of my controller would probably at least be on par with the Morningstar. After all, we’re looking at tenths of a percent here – in the real world, not that big of a deal anyhow. And tenths of a percent at the power levels we’re talking about are more on the order of watts rather than sub-watts – fairly easy to resolve with basic test equipment. Incidentally, judging by the FM80's published efficiency graphs, it appears that it's slightly more efficient than the Morningstar in some instances.

    The efficiency graph for my controller is in the manual (http://www.roguepowertech.com/documents/MPT3024B1.pdf) on page 23.

    Now don’t get me wrong – the new Morningstar looks nice. In particular, it has a neat variety of networking options (which, in my opinion, is its main selling point for those that need such options). In any case, the Morningstar is in a slightly different league that my controller, and maybe will give the Outbacks and Xantrexes a run for their money.


    Harley,

    Sorry, I don’t have any blems or returns. I might have a beta unit coming back soon because the guy is upgrading to a larger array…I’ll inquire about that this week and let you know.


    Oh, and the Rogue versus Rouge thing…haha…I’m located in the Rogue Valley of Southern Oregon, named after the Wild and Scenic Rogue River. Just in case anyone was curious as to where the name came from.


    Marc
  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Okay, so looking at the manual for that new TriStar MPPT I see that my understanding was in fact backwards. (Which I suppose should be called un-understanding.)

    I thought that the controller took the incoming voltage/amperage and down-converted it to "the best voltage to charge the battery". My un-understanding was in thinking that "the best voltage to charge the battery" was a variable.

    But apparently, that is not so.*

    On the output side, the controller acts like any other multi-stage charger; it puts out fixed charging voltages for the various charging stages. On that particular controller the charge voltages are pre-set via DIP switches.

    So, voltage variances only take place on the input side, which causes a change in the amperage available on the output side - but does not vary the voltages on the output side (other than normal float/absorb charger type behavior) since the charge voltages are locked in.


    Have I got it right?


    (And it looks like I owe stephendv a beer. /me nods)


    *Why not? I.e., why is the "best voltage to charge the battery" not a variable (beyond the relatively inflexible pre-programmed bulk/absorb/float)? Ignoring for the moment the different battery types (gel/agm/fla/etc) and speaking hypothetically...

    Surely 14.4v (for example) is not the optimum voltage in all cases? Take two batteries of the same type: one is at 12.8v and one at 13.4v. Is 14.4v (or whatever the manufacturer recommends) the optimum charging voltage in either case?

    Would it not be more efficient to charge at some voltage which is a certain value (percentage perhaps?) higher than the existing battery voltage? Thus as the battery voltage rises, the charger voltage rises along with it?

    Is there some reason why this isn't practical?
  • lorelec
    lorelec Solar Expert Posts: 200 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    dwh,

    The output of the controller is variable while functioning as MPPT, only in the sense that it follows the battery voltage wherever it goes. As the controller pushes current into the battery, the battery voltage will rise and so will the output voltage of the controller...until it hits that "magic" point of 14.4v or whatever the controller is set to absorb at. At that point, the output is regulated at that voltage so that the battery voltage remains stable. If the battery voltage begins to rise above (say) 14.4v, then the controller decreases charging current, forcing the voltage to drop. Or if the battery voltage begins to fall, then the controller increases charging current, forcing the voltage to rise.

    Marc
  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller
    dwh wrote: »
    On the output side, the controller acts like any other multi-stage charger; it puts out fixed charging voltages for the various charging stages. On that particular controller the charge voltages are pre-set via DIP switches.
    This is a common misconception of how things actually work.

    The charge controller does not actually put out fixed voltages - it attempts to - which is not the same thing. In almost all cases, the battery would "swamp out" that voltage and pull it down to the battery voltage + some small amount of IR drop from internal resistances. All good MPPT controllers adjust for that difference between the "max" and what the battery is actually at for voltage.

    So what happens is that the controller will attempt to feed the battery, say 14 volts. But the battery is pulling so much current that it would pulls the panels down to 12 volts if connected directly. Eventually the battery will get to 14 volts, then the controller will drop back to say 13 volts for a trickle charge or float charge. Look at those voltage parameters on controller specs as a max, rather than a fixed number.

    Many years ago I had a power supply that could actually feed an 80% discharged battery 14.2 volts under full load, and it was ugly. The battery got very hot within a few minutes.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    One issue with using separate devices to measure voltage and current is that with any switching power supply, things are not strictly DC. This is where power analyzers come in as it simultaneously sampled to calculate power values which are what is used to compute efficiency.

    PvPower was the poster child for this, they were claiming they had the best Gridtie inverter and the worlds best efficiency at 97.5% ( this is back in 2004 ), my and yokogawas showed is was 93.9% ... big difference and was the driving force behind CA requiring UL witnessed and verified efficiency number, which we don't have for charge controllers. Turns out they were doing exactly what you were, but with AC gridtie, they completely snookered things.

    I see a few tenths of percentage difference due to power factor differences so that's something to watch out for using the calculator method and separate instruments. there is also the issue of accuracy of using different instruments vs an all in one which is verified for accuracy.

    I have no doubt for its power and voltage class your controller can perform well, your postings on your design shows you have optimized in the places to get the best performance and I agree with BB, for a certain customer base, the do it yourself can be fun and have appeal.

    As for the FM series, the FM60 and FM80 are electrically identical ( well the units I have had apart ) and they are exactly the same as boB's MX60, the only difference for the FM80 is the big fan added for more forced air cooling. I have run countless times efficiency on the OB units, they are not better at any power level or voltage that is within the 60 amp limits. The OB has a relay to power and an inefficient flyback supply for the internal power rails, the unit has an active idle as I recal of almost 9 watts on 48V battery's, really eats into the efficiency numbers
  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller
    lorelec wrote: »
    "...but some of the documentation was a bit sparse..."

    Funny, I've had lots of positive feedback specifically on how thorough the documentation is. If you could tell me where you think it's lacking, maybe I can improve it some. I don't blame a retailer for not carrying my product, and I don't expect them to.
    Never mind, it seems that we have some confusion here, and also possibly some trademark issues. There are two companies making "Rogue" charge controllers:

    https://www.rogue-engr.com/cportal/index.php?option=com_virtuemart&Itemid=45&vmcchk=1&Itemid=45
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    The magic was the Outback CC allowed long distance wire runs but had HICCUPS!
    The magic now is the Xantrex CC allows long distance wire runs!
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • harley4jcs
    harley4jcs Registered Users Posts: 10
    Re: BZ 250W/25A Solar MPPT Charge Controller
    lorelec wrote: »
    SG,




    Harley,

    Sorry, I don’t have any blems or returns. I might have a beta unit coming back soon because the guy is upgrading to a larger array…I’ll inquire about that this week and let you know.




    Marc

    Cool, Please let me know if it works out...Thanks Harley
  • lorelec
    lorelec Solar Expert Posts: 200 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Harley,

    Looks like I'll have the beta unit back this coming week. Look for a message from me with details.


    SG,

    True, things aren't strictly DC. The input of the buck might be one are of concern, but a good design adds enough bulk capacitance to the input to counteract its discontinuous nature, and leaves us with essentially a DC current...enough of one for a pretty accurate measurement, anyhow. Many semiconductor and power supply manufacturers suggest the 4-meter approach in their application notes, so it must not be all that bad.

    Anyway, a controller that's a few tenths of a percent from the next guy's is pretty much equivilant in my opinion. That's only a few watts (maybe a few tens of watts if you get into the upper kW levels). And even that could be offset by a difference in temperature when the measurements are made.

    Marc
  • momofgcm
    momofgcm Solar Expert Posts: 35
    Re: BZ 250W/25A Solar MPPT Charge Controller
    icarus wrote: »
    You want to know how bad this controller REALLY is? I was messing around with couple of new panels this morning and I plugged into the controller and then then into a starting battery, with a 100 watt load on the battery. Now the panels were showing 5.6 amps into 12.2 volts. Cool panels, cool morning. Now the panel showed 5.6 amps, about right given the slight haze in the morning. The on board ammeter showed that the amps INTO the battery was a 5.1 amps. So it appears that the Mppt advantage was a whopping ~10% NEGATIVE!

    So the controller's own on board display is telling you that this is a POS!

    Tony

    I understand the magic of the MPPT controller is that it can down convert as well as UP convert. Since the potential on the input side of the controller is below the set charging V, the algorithm kicks in and up converts the input voltage to the optimal charging voltage. That in turn results in a lower current seen on the battery side. There was enough power coming into the controller to allow the conversion. It results in a battery charge that wouldn't have been possible with the actual output of the PV panels. If it were a PWM controller, the incoming voltage would never have triggered the controller to charge and all the energy would have been lost.

    Therefore, it makes sense that you would get less current into the batteries because the controller converted that current that was 'lost' into V to bring the potential up to the charging voltage to allow the batteries to charge.

    That is how I understand the MPPT process to work. Is that right??

    I don't know how efficient the BZ converting process is but I'd sure like to know.

    So, how do we know the BZ is a bad controller?? I see a lot of you have them in your junk drawers!! Why did you not like them? A lot of the posts I read are older. Do you know if the more recent models are the same as the old or have they been improved?

    This is an inherited controller and was purchased within the last year.

    Kim
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    see if this verifies your thoughts on it.
    http://www.windsun.com/ChargeControls/MPPT.htm
  • momofgcm
    momofgcm Solar Expert Posts: 35
    Re: BZ 250W/25A Solar MPPT Charge Controller

    It sounds like it does. What am I missing?

    Is the mppt as efficient on an up convert as a down convert?


    Kim
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    I think currently, MPPT only down converts. There is a story that a future offering from Midnight ?? could also do up converting or both.
    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 ,

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller

    they currently only downconvert. the classic i believe will be able to go both ways.
    i know what you're thinking. shame.:blush:
  • momofgcm
    momofgcm Solar Expert Posts: 35
    Re: BZ 250W/25A Solar MPPT Charge Controller

    I assumed they went both ways. Why would they not?? That would significantly improve the system.

    As a DC-DC converter it shouldn't matter which way you convert. Hmmmmm.

    Kim
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: BZ 250W/25A Solar MPPT Charge Controller

    Actually, to build a rugged and efficient charge controller, UP, Down, and Up/Down converters are all very different from each other (electronically speaking). Mostly Buck type converters are used here--they tend to be rugged, relatively inexpensive, and the most efficient. The only requirement is that the Vpanel voltage is above Vbatt.

    Boost converters can only increase voltage--so they would require the output voltage to be higher than the input voltage of the controller--But that is usually not something we want to design for--it makes the solar array cabling run at a lower voltage and higher current--requiring heavy and more expensive copper cabling.

    Buck/Boost can do up and down converting... Certainly the most versatile setup--but tends to be less efficient and more parts count (and more expensive).

    Maybe the Midnite solar guys will be teaching us some new lessons in the near future. :D

    From another thread--I posted this explanation about DC converters--if you are not into electronics and power supplies--don't be surprised if the following is totally unhelpful:
    BB. wrote: »
    For anyone interested in types of switching digital power supplies, here are a few links:

    Switch Mode Power Supply

    Major types of Non-Isolated switch mode power supplies (from above link):

    boost converters
    buck converters
    buck-boost converters

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • lorelec
    lorelec Solar Expert Posts: 200 ✭✭
    Re: BZ 250W/25A Solar MPPT Charge Controller
    I assumed they went both ways. Why would they not?? That would significantly improve the system.

    As a DC-DC converter it shouldn't matter which way you convert. Hmmmmm.

    Depends on what kind of DC-DC converter the controller uses. I think all of the controllers on the market today are based on the buck, which makes boosting the voltage of a solar panel physically impossible.

    In most installations, there's no need to boost. You wire your array for a nominal voltage that equals that of the battery or higher. If you go higher (bucking a 24v panel to 12v, for example), you reap the benefit of lower wiring losses. Going lower (boosting a 12v panel to 24v) offers no real benefits, aside from the possible convenience of being able to do it. Using a panel of the same nominal voltage as the battery (say, 12v --> 12v) might very seldom benefit from boost if you have a very hot panel and a very full battery, such that the Vmp of the panel is below the charging voltage of the battery -- but even then we're talking boost of maybe a volt or two. Probably not worth the added complexity, expense, and efficiency penalties of making the controller buck-boost.

    Marc