question

primemeridian avatar image
primemeridian asked

Victron SmartSolar 100/50 pulls nothing from solar panels

I have seen this issue discussed multiple times, but I am still not sure what to do about it. Why is this happening so often? I installed my SmartSolar 100/50 and it worked fine. Lately, it will not pull any power from the solar panels to charge the batteries. Even if I disconnect the solar panels and the batteries, the system does not reboot and start working properly. My history shows that it has been working but now VictronConnects alwayd displays 0 watts from the solar panels.

How do I fix this?


MPPT ControllersMPPT SmartSolar
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7 Answers
klim8skeptic avatar image
klim8skeptic answered ·

How do I fix this?

You dont give any details for diagnosis.?

It might be best to have a look at the trouble shooting section of the manual.

Grab a multimeter and report back what you find.

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primemeridian avatar image
primemeridian answered ·

Ok. I guess I did not provide much detail because so many people have reported the problem. I have measured everything multiple times and read manuals multiple times. I will redo that now and report back. The troubleshooting section does not touch on the problem. Thanks

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silverliningsolar avatar image
silverliningsolar answered ·

Hey PrimeMeridian:

I have found this to happen occasionally too.

  1. Disconnect everything (solar first)
  2. Disconnect batteries
  3. Wait a good 5-10 minutes
  4. Power unit back up (ie: reconnect batteries and ONLY batteries) and WAIT a good 2-3 minutes
  5. Log into the device via BlueTooth/VictronConnect
  6. CHECK FOR FIRMWARE UPDATES and update as necessary
  7. Then, and only then, reconnect your panels/solar.

** It goes without saying - or maybe not - to check the voltage at your solar/pv output with a meter and be sure it is AT LEAST 5 volts higher than the battery - and NOT higher than the maximum input voltage of the controller. (ie: 100 volts in your case). You may even find the VOC dips enough to drop it below that magic 5V, once a load is put on, so check it again once re-connected, right at the PV terminals on your controller.



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kevgermany avatar image kevgermany ♦♦ commented ·
Once a load is applied, the panel voltage only needs to stay 1V above battery for charging to continue.
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primemeridian avatar image
primemeridian answered ·

OK. Here are the gory details. Something is definitely wrong.

Solar Panel Specifications

2 Sunpower SPR-E-Flex 100

  • 100 W
  • Rated voltage: 17.5 V
  • Rated current: 5.8 A
  • Open circuit voltage: 21 V
  • Short circuit current: 6.2 A
  • Max system voltage: 45 V
  • Series Fuse rating 15 A


2 Sunpower SPR-E-Flex 110

  • 110 W
  • Rated voltage: 18.5 V
  • Rated current: 6 A
  • Open circuit voltage: 21.7 V
  • Short circuit current: 6.3 A
  • Max system voltage: 45 V
  • Series Fuse rating 15 A


Solar panel configuration

  • All 4 panels installed in parallel
  • 2 joined outside with solar splitter connectors
  • Final pair positive cables joined via battery switch (OFF, FORE, AFT, and BOTH) to MPPT pos. PV post
  • All negative cables go to common bus bar to that connects to MPPT negative PV post


Battery Configuration

  • 3 198 AH AGM batteries connected to common bus bars
  • Negative bus bar connected to shunt
  • MPPT, Inverter/Charger, Alternator connected to house side of the shunt with appropriate fuses
  • Engine battery is separate and charged using an Echo Charger


While battery charger engaged 9 am:

  • Reading of panels at the MPPT controller

    • Volts = 20.68
    • Amps = 0 A
  • Reading of panels in VictronConnect

    • Volts = 20.69 V
    • Amps = 0 A
    • Watts = 0 W
  • Battery voltage using multimeter at MPPT connections = 16.59 V
    This seems very wrong.
  • Battery voltage per VictronConnect to SmartSolar = 13.49 V
  • Battery voltage per SmartBatterySense = 13.49 V
  • Battery voltage per Xantrex Freedom Inverter/Charger = 13.5 V



While battery charger DIS-engaged 9:04 am:

The boat is still plugged in, but all other charging source are turned off. Solar only.


  • Reading of panels at the MPPT controller

    • Volts = 19.7 V
    • Amps = 0 A
  • Reading of panels in VictronConnect

    • Volts = 20.69 V
    • Amps = 0 A
    • Watts = 0 W
  • Battery voltage using multimeter at MPPT connections = 16.59 V
    Again very bad.
  • Battery voltage per VictronConnect to SmartSolar (Absoprtion)
    = Initially 14.30 V but dropped to 12.7 V after 5 minutes
  • Battery voltage per SmartBatterySense = 12.72 V
  • Battery voltage per Xantrex Freedom Inverter/Charger = 12.7 V



During complete shut down of all systems:

  • Shore power disconnected
  • All 12 V panel breakers off
  • PV panels disconnected. 0 V at MPPT
  • Battery switches off. 0 V at MPPT


After full shut-down and turned on batteries without any solar panels, the SmartSolar did not restart. It was not visible through VictronConnect and displayed no lights.

  • Battery voltage at MPPT connection by touching the screws on the MPPT controller = 2.75 V
  • If I pull the wires out of the MPPT, the voltage reads 12.7 V
  • If I reinsert the battery wires, the voltage at the screws on the MPPT = 2.75 V


When I turned on the SolarPanels, the SmartSolar MPPT started and was available through VictronConnect


After full shut-down and reboot. Battery charger off.

  • Reading of panels at the MPPT controller

    • Volts = 20.4 V
    • Amps = 0 A
  • Reading of panels in VictronConnect

    • Volts = 20.37 V
    • Amps = 0 A
    • Watts = 0 W
  • Battery voltage using multimeter at MPPT connections = 16.53 V
  • Battery voltage per VictronConnect to SmartSolar (Float) = 12.89 V
    Battery voltage per SmartBatterySense = 12.7 V
  • Battery voltage per Xantrex Freedom Inverter/Charger Monitor= 12.7 V



I think my MPPT controller is hosed.


Also, here is a screen shot of my history from 20 days ago. So, it was working for a long time.

smartsolarhistory.png


smartsolarhistory.png (130.8 KiB)
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klim8skeptic avatar image
klim8skeptic answered ·

After full shut-down and turned on batteries without any solar panels, the SmartSolar did not restart. It was not visible through VictronConnect and displayed no lights.

Battery voltage at MPPT connection by touching the screws on the MPPT controller = 2.75 V

The lack of leds would indicate no battery present, voltage reading of 2.75v would confirm a battery related problem.

Have a very good look at the wiring between the mppt and battery. Check the fuses/breakers and joins/crimps thoroughly.

Battery voltage using multimeter at MPPT connections = 16.59 V
This seems very wrong.

This could be due to smart networking. And the disconnection of the mppt to the battery.

Is the mppt smart networked to the SBS?

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primemeridian avatar image
primemeridian answered ·

Just want to wrap this up and clarify.

I initially started this post to question why I had to always reboot (reset) my SmartSolar MPPT Controller after using the alternator or a charger. That process seemed unreasonable. The system was working fine 3 weeks ago, when I headed offshore. While offshore, I did have to run the engine and therefore the alternator. Whenever we were under sail, the solar controller would not automatically takeover and start charging.

Once back on shore, I started this thread and digging deeper. This is when I determined that the MPPT controller is not working at all, even after a reset. The connections are all fine. Full battery power is being delivered to the MPPT controller.

At this point, I will be replacing the unit.

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kevgermany avatar image kevgermany ♦♦ commented ·
Assuming it's a 12V system, your high battery voltage is preventing the MPPT from working. No way AGM should be this high. But looks as if this reading is an MPPT fault.Hopefully the MPPT is still within the 5 year warranty period.

You'll probably get better results by wiring the panels differently. Two series strings, each of one 110W and one 100W panel. Max currents are similar, but voltages not.


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ahtrimble avatar image
ahtrimble answered ·

kevgermany sounds correct. If the MPPT is reading the batteries at 16.59v then the MPPT won't turn on due to the charging profile. And 12v batteries at 16.59v sounds way out of line...probably fraudulent. If it were true I would think the batteries would be fried.

I experienced our MPPT (150/70) non-charging twice in 2 years. I shut down the panels to the MPPT, shut down the batteries to the MPPT, waited a minute, and did a restart. All was fine. There is obvioualy some kind of bug somewhere in the MPPT so I will keep on the firmware updating and hope it gets worked out. I will be adding a second 150/70 in a month along with more panels. Hopefully they won't both suffer this shutdown at the same time...or maybe the linking and update will prevent it altogether.

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Related Resources

MPPT Product Page

MPPT Error codes

MPPT 150/60 up to 250/70 Manual

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