So yesterday I had just upgraded my Victron MPPT 100/20 controller that I had been maxing out its specs, to the point that a big bubble formed in the top of the plastic case! Thankfully it was a quick Amazon return item. I had not planned on replacing/upgrading it, but I had a particularly bright sunny cloudless day that really tested its limits. Even to the point of going overvoltage by a couple of volts sending it into fault mode. So I packed it up and send it back. At this point I had decided to get a beefier unit that could handle my panel setup better, 3 Sharp 230watt poly panels ND-U230Q2BX, as I knew the 100/20 controller was pegged out at 20Amps and 550watts output and got very hot. So I looked at the 100/30 and higher units. The new 150/45 model caught my eye as it was the first model that allowed the attachable small display panel to be attached directly to the unit for about an extra $50. So I set it up yesterday morning. Before this my max output for a full sunny day with the 100/20 was about 1.7kWh of power for a day with the 3 sharp panels that I had only been running for about a week on the 100/20 controller. Yesterday I setup the new 150/45 unit around 8am and by the end of the day I generated a whopping 4.3kWh of total power! Not bad for having a controller that allowed the panels to put out what they wanted.
So here is the strange part, I have 3 panels at 230W each, total should be 690w right? At least I think so. Today started as a very overcast and cool day, to the point of being chilly and a breeze blowing. I live about 8 miles due east of downtown Los Angeles. June gloom we call it. Anyway, the entire morning was cloudy and cold-ish. The system was putting out anywhere between 80-200watts depending on the cloud cover. Around 1:30pm there was a break in the clouds for about 5 solid minutes of pure sunshine.
The output of my system jumped to 860watts for about 3 minutes! It shot up to 30amps of charging power. Now also to note, I have 2 12.8v Valence U27-12Xp batteries in series for 24volts that was at about 50% SoC. Normally on a sunny day they would have been around 95% at this time of day, but because of the cloud cover all day never really got much juice back in them. So the batteries could take quite a bit of current to charge. If they had been nearly full, the controller would have limited the max output of the panels to only what the batteries needed.
So my question as the subject asks, has anyone else seen their panels output 25% over their max rated power rating like this? The panels say they can output +10%/-5% of Pmax under STC on the label. I have a theory why this happened, but even taking into consideration of the temperature coefficient of the panels this seems excessive.
So here is the strange part, I have 3 panels at 230W each, total should be 690w right? At least I think so. Today started as a very overcast and cool day, to the point of being chilly and a breeze blowing. I live about 8 miles due east of downtown Los Angeles. June gloom we call it. Anyway, the entire morning was cloudy and cold-ish. The system was putting out anywhere between 80-200watts depending on the cloud cover. Around 1:30pm there was a break in the clouds for about 5 solid minutes of pure sunshine.
The output of my system jumped to 860watts for about 3 minutes! It shot up to 30amps of charging power. Now also to note, I have 2 12.8v Valence U27-12Xp batteries in series for 24volts that was at about 50% SoC. Normally on a sunny day they would have been around 95% at this time of day, but because of the cloud cover all day never really got much juice back in them. So the batteries could take quite a bit of current to charge. If they had been nearly full, the controller would have limited the max output of the panels to only what the batteries needed.
So my question as the subject asks, has anyone else seen their panels output 25% over their max rated power rating like this? The panels say they can output +10%/-5% of Pmax under STC on the label. I have a theory why this happened, but even taking into consideration of the temperature coefficient of the panels this seems excessive.
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