question

nick-a avatar image
nick-a asked

smart mppt 100/20 goes up and down like a Yoyo and crashes output to zero

screenshot-20210725-153306.jpgscreenshot-20210725-152345.jpgMy setup:


1 solar panel Wattstunde WS200SB (200W, Umpp 19.8V, Impp 10.1A).

Attached to a smart solar MPPT 100/20 with the latest firmware 1.56. Victron Connect thinks it is a 48V version as well as my Raspberry Pi. The label on the device tells otherwise (ie no 48V written on it)

Four 75 Ah LiFePO4 in series with BMS. (Home made pack)


(Sidenote: is there a physical difference between the two MPPT models? Or are they the same?)


screenshot-20210725-152324.jpg

Main problem is that the mppt crashes its output to zero and starts up again. see the attached pictures. I have no clue why. I checked the BMS. No problems with it. It does not trip any error coditions.


I want this to be resolved. MPPT crashing all the time to zero output is not good.

What is going on? Is this the same bug that ought to be resolved in this firmware revision?

Is my MPTT broken and need to be replaced?

Or is it a problem that there is 1 solar panel attached with an output of only 5V above the battery? Do you have the same problem with 1 panel?


Any help is appreciated.


Victron experts can have a look at the VRM data Portal ID: b827eb30b15f


screenshot-20210725-150302.jpgscreenshot-20210725-152329.jpg



MPPT ControllersMPPT SmartSolarfirmware updatebug report
screenshot-20210725-150302.jpg (345.3 KiB)
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screenshot-20210725-152329.jpg (295.7 KiB)
screenshot-20210725-152345.jpg (318.1 KiB)
screenshot-20210725-153306.jpg (383.3 KiB)
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2 Answers
nick-a avatar image
nick-a answered ·

I hope that Victron can chime in on this issue.


I started another thread: https://diysolarforum.com/threads/victron-smart-mppt-100-20-goes-up-and-down-like-a-yoyo-and-crashes-output-to-zero.26010/

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Stojan Nejkov avatar image
Stojan Nejkov answered ·

Hi All, probably a bit of a late reply, however I just had the same issue with my system (which has been in service for 2 years now), cleaning all the main fuse connections between Battery Bank, Inverter and MPPT seems to have fixed my situation. I had the same problem last year with my daughter's system and there again the issue was in the connections.

Anyway - perhaps check your connections when you see the MPPT yo-yoing like this - it might be just that.

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