Announcement

Collapse
No announcement yet.

MPPT charge controller behaving as PWM of late

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • MPPT charge controller behaving as PWM of late

    Hello everyone,
    I have a small Off grid solar unit at home.
    It consists of 2x 400W solar panels (40V rated at 5.3A, 44VOC)
    I am using a small MPPT charge controller as below-
    https://www.urjakart.com/systellar-2...ontroller.html

    The system had been working happily since last 2 years. It generates about 20A in Midday sun for 12v FLA batteries. The MPPT would place panels near 36~38V, suck about 8~9 Amps and convert it to 18~20A into 12v Lead acid batteries for charging.

    However, Since a few weeks I am noticing that MPPT is behaving more like PWM.
    Panel voltage is roughly near 14.5 to 15v at all times of the day. Amps near 8~9A.
    As a result I get only half the amps that I had paid for. If I disconnect the charger, panels jump back to 40V.

    I have tried disconnecting everything, let MPPT cool overnight (I assumed it could be due to overheating or software hang) but it has'nt improved this morning.

    Please help.

  • #2
    Generally, with MPPT chargers, as the batteries require less power, the charger reverts to PWM mode (both mine do) but if the battery voltage goes low, they then go to MPPT mode to harvest as much as possible,
    Powerfab top of pole PV mount (2) | 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

    Comment


    • #3
      Originally posted by Mike90250 View Post
      Generally, with MPPT chargers, as the batteries require less power, the charger reverts to PWM mode (both mine do) but if the battery voltage goes low, they then go to MPPT mode to harvest as much as possible,
      This wasnt its behavour past 2 years. Even if batteries were fully charged, it would hold the panel voltage near 35~40V and trickle charge a few amps into battery (As low as 0.3A). So far I have'nt seen panel voltage above 15.5v this week.

      Comment


      • #4
        Could there be a problem with your panels, or wiring to the controller? Never seen that particular controller before. I see the warranty is two years, hmmm....
        2.2kw Suntech mono, Classic 200, NEW Trace SW4024

        Comment


        • #5
          Sounds like a problem with the controller. However, to rule out panel issues, I would disconnect both modules from each other and the controller and measure Voc to rule out bypass diodes or damaged internal wiring ( I doubt you will find anything). Second, I would connect only one module to the controller and see what it does. Then disconnect that one and connect only the other one, and again see what happens (with voltage and charging current and all that). If the two modules operate in an identical manner, then I would rule them out as the problem.

          It sounds like the controller buck circuit failed and is shorting the battery to the modules. The controller doesn't seem to have any PWM setting so for it to operate this way might indicate failure. Manual for the controller is here: http://systellar.co.in/wp-content/up...r-2015-Web.pdf

          Be safe!

          Comment


          • #6
            Originally posted by rwest View Post
            It sounds like the controller buck circuit failed and is shorting the battery to the modules. The controller doesn't seem to have any PWM setting so for it to operate this way might indicate failure. Manual for the controller is here: http://systellar.co.in/wp-content/up...r-2015-Web.pdf

            Be safe!
            Seems like this was it. The "MPPT" Part had failed. And Interestingly it reverted to PWM style Operation rather than Shutting down or Throwing up and error code. I had to send it to the Manufacturer and got it repaired for INR 1000. The performance is now back to regular levels.

            Comment

            Working...
            X