ripper avatar image

SmartSolar 100/20 malfunctioned, bug hunting for voltage when going to float , cooking batteries

My SmartSolar went crazy today midday. The batteries were mostly charged, so the voltage acted swiftly to put in charge. The SmartSolar seemed to have trouble to adjust the voltage slowly, it just went full throttle, voltage rose to 29.5V (28.8 set to), it then fully decelerated into the low 2 digits when the voltage came right back down and shot back up all the way every other second. It started at around 1340h when the yellow line spikes into the blue zone start appearing. Load connected at 1405h, disconnected 1440h and back it went into the blue. I have never seen this behaviour before. It acted up in bulk and absorp, only way to calm things down was putting on enough load. On the logging one can see switching between bulk ans abs because of heavy machines starting. It acted up all on its own, everything else was stopped and disconnected for fault finding. When stopping the load, the erratic behaviour was back the instance 28.8V was reached.

I seem to think it hung up when it should have gone into float. The batteries were charged this morning by a battery charger after the smartsolar had started to work. That was the first time I interfered with the smart solars "rhythm". If, I usually charge at night. It went from bulk to abs to float basically doing nothing from 1100h to 1200h, on the left the charger is in abs at 28.8V, smartsolar in float doing nothing at 27,6V. Charger disconnected at 1200h, smartsolar switching to bulk and following abs at 1245h. Reasonably it could have switched to float at about that point and went ballistic instead.

At 1500h, I had it reset and it worked fine afterwards. That was counted as a new day though

This is the second time in a week (bluetooth connection hung up the first time) I had to disconnect the unit after it performed flawlessly for over a year.

Is it on its way out? Is it a bug? Can I make sure that doesnt happen again? Am I doing something wrong with charging? The batteries will probably be toast if that was to develop during weeks of absence apart from the hazard of fire.

smart solar set-up help
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1 Answer
Daniël Boekel (Victron Energy Staff) avatar image

Hi @ripper

Can you post your screenshots with more information? I have no idea what line means what..

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On the top

Light blue PV voltage

Red MPPT temperature

Dark blue amps going to battery from MPPT

Green is charging mode, bottom bulk, middle abs, top float which was only reached in the morning while charging on genny.

On the bottom

Yellow battery voltage

Green PV watts

A block of highly fluctuating lines from 1330h till 1400h does not usually happen.


Please @ripper

The numbers are cut-off the screenshots!