MPPT controller

conntaxman
conntaxman Solar Expert Posts: 125 ✭✭✭✭✭
in Solar Beginners Corner #1
MPPT controller

I would like to know if any one has one of these controllers, I have bought one solar controller and the company said that it is mppt.I still have to put a amp meter at each side of it to get the readings,or the volts. But im going to have to get a larger one and found this on ebay, here is the link and would like input from others.I have emailed the company/person and he has explained to me how to see if they are really mppt controllers, he says this one is .Im thinking of getting the 60 amp one. here is the link for the spec.
http://www.mppsolar.com/Photovoltaics/MPPT%20SCC-2.pdf
tks guys. with shipping its about $300.00. What i like about it is the high voltage for the input and also the amp's.But mainly the input voltage.
tks
John
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Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,642 admin
    #2
    Re: MPPT controller

    Says all the "right things"... Interestingly, you need to run a higher Vmp-array because the DC input current is limited to 25 Amp (40 amp output) or 35 amps (60 amp output)... So, Vmp-array has to be (roughly) at least 1.7x the battery charging voltage to not hit the PV Input current limit.

    May make it difficult to match Vmp-array on a 48 volt battery bank with 60 amp output (~Vmp-array 107 volts--In very cold weather, it is possible the controller would over voltage at Voc-cold if trying to get the 60 amps * Vbatt-charging maximum rating).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • conntaxman
    conntaxman Solar Expert Posts: 125 ✭✭✭✭✭
    #3
    Re: MPPT controller
    BB. wrote: »
    Says all the "right things"... Interestingly, you need to run a higher Vmp-array because the DC input current is limited to 25 Amp (40 amp output) or 35 amps (60 amp output)... So, Vmp-array has to be (roughly) at least 1.7x the battery charging voltage to not hit the PV Input current limit.

    May make it difficult to match Vmp-array on a 48 volt battery bank with 60 amp output (~Vmp-array 107 volts--In very cold weather, it is possible the controller would over voltage at Voc-cold if trying to get the 60 amps * Vbatt-charging maximum rating).

    -Bill
    Hello Bill, I'll be running a 24volt battary sys.[was going to run a 12v.but changed my mind] Many told me to go 24v. I just glad that i didn't buy my 1500watt pure sine W. inverter already.
    I looked at this and talked with the person, and everything sounded good.
    I like the input voltage part. Most of the other ones are up to about 55volts input. Except if you want to spend ALOT of money.
    Thank for the input.
    John
    I have about 1040watts of panels.[16 panels of 65watts.]Right now im only running 2 in series and then Par. my controller now only has a 55volt input.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
    Re: MPPT controller

    +/-1v ripple voltage. yikes!!!!! i wouldn't touch that with somebody else's 10ft pole.
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #5
    Re: MPPT controller

    Hi John,

    There are several things that you might want to consider regarding this CC.

    1. The data sheet mentions that the recommended batt types are Sealed types. This might mean that there is a limited range of charge voltage settings, etc. If this CC does NOT do Flooded batts, would this meet your needs?

    2. There is a single Temp Compensation value noted. If this CC uses a fixed temp comp value, is this corrrect for the batts you intend to use?

    3. Does this CC use a Remote Temp Sensor for the battery Temp Comp? This would be essential for sealed type batts in most applications, as SLA batteries are often very sensitive to having correct charge voltages.

    And, agree with niel, the Max Rupple seems very high. The batteries should filter the ripple, but, there would still be a ripple current, which the batteries may not enjoy over a long time period.

    Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #6
    Re: MPPT controller
    Vic wrote: »
    Hi John,

    There are several things that you might want to consider regarding this CC.
    And, agree with niel, the Max Ripple seems very high. The batteries should filter the ripple, but, there would still be a ripple current, which the batteries may not enjoy over a long time period.

    Vic

    If you were using a PWM controller, the ripple (before any filtering in the CC) would be the full charging voltage, as the controller switches on and off trying to meet the current and voltage limits, so I am not sure that the +/- 1 volt is really significant. And, as you say, the battery is behaving as a very good filter/capacitor and accepting pulses of current. Specifying the open circuit ripple on a CC does not make any sense, and the ripple under load depends entirely on the internal resistance of the battery. The panels are not going to deliver an unlimited current to the battery during the peaks.
    I would be concerned if the effect of the ripple were to cause the voltage to peak at (Float + 1 volt) during float, for example, since that could end up pushing more current through the battery than it would normally take at a true Float setting. (There probably would be no back-flow from the battery on the low end peaks of the ripple.)

    I, on the other hand, would not touch it with a ten-foot pole because it is not UL-listed. :-)
    SMA SB 3000, old BP panels.
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