I was hoping someone experienced on this issue could confirm something for me.
So I have finally placed an order for 2 more solar panels to add to my current existing one. so in total I’ll have 3 panels wired in series with the following VOC. (41.2 + 41.2 + 49.90) = (132,3 VOC). Since I’m quite new to this, I just discovered panels have a (solar coefficient). Meaning that in winter the VOC will increase for each panel, and I didn’t account for this, since I was just happy to find panels that were below (the max system VOC of 145).
So the question is, incase the VOC accidentally shoots passed the max VOC, does the AC200max have overvoltage protection for the solar input? or is the solar charger immediately destroyed?
I’m currently based in Johannesburg, South Africa and our winters typically range between (5° to 0° Celsius) coldest and get warmer during the day upwards to (19° Celsius). So I’m not sure if that will increase VOC high enough to reach max or damage something. (But I’m genuinely interested in knowing how deadly such a mistake could be)
If you have insight on this issue or have accidently gone past the max VOC what’s your experience and suggestion on this issue.
Hello Sir,
Ideally you would receive an alarm and the alarm would read “warning PV overvoltage”. Your PV input would be cut off until the incoming PV voltage is reduced into the recommended range. There is also the possibility of frying your power station. The max voltage is hard set and even a safety margin of below 20% of the listed voltage max is best practice. Good luck, and there is supposed to be some flexibility with the max wattage, but voltage is critical.
So that means, it’s just a matter of hoping for the best. (meaning the alarm goes off and cuts power?) before destroying anything. Winter is in 2 months so it will be the first time, seeing how high the VOC gets.
(fingers crossed).
The Voc rating on the panels themselves are good enough to trust.
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I have the AC500 with a max Voc of 150V for each of the two inputs.
I use three 550W bifacial panels with a Voc of 49.95V, in series for a total of 149.85V. Never had an overvoltage alert and I’m in Las Vegas with blue skies and sunshine almost everyday, (and yes it does get cold here).
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Keep in mind that you want to overpanel, that is, build an array with more wattage than is called for, because the wattage ratings of panels is always LESS than advertised. My 3 bifacials have a theoritical Wattage of 1650W but the APP shows it only gets to around 1490W.
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Overpaneling also helps on cloudy/overcast days, with those extra panels collecting more light.
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There is always some voltage differences between panels from the same company, and these bi-facials only come in pairs so I have one panel left over. I took readings for each and chose the 3 with the highest voltage readings and wired them in series. The 4th panel is wired directly to the PV input of one of my B300s batteries, as are some leftover panels from other projects.
Bi-facial panels seem like a good idea, but that means you can’t mount them against a surface like a roof. The backside needs to get some reflected light. I just happen to have a light colored block wall fence behind the panels to catch that light.
I’m happy to hear that you can cut it so close and still be fine. And yes overpanelling is something I’m trying to go for, since the current panel I have is (545w) but so far that’s under perfect conditions for about 30 minutes or so before dropping down to the average of (350w to 450w) range.
With regards to (VOC) I believe I should be fine for 3 seasons out of the year no issues, my only concern was the winter. Even though our winters are nowhere near as cold as other countries out there, I just wanted to be a bit cautious and careful.
I also considered getting Bi-Facial panels but I couldn’t find any with a low enough (VOC) to be able to fit 3, since the max VOC of the AC200max is (145). Which is (5) less than the AC500.
I hope I never go over the max VOC in winter, but if it accidently happens, I’m hoping the system has means of protecting it self.
Kind Regards
Unfortunately, the built-in protection mechanisms in BLUETTI units do not include exceeding the solar panel’s VOC (Voltage Open Circuit).
Depending on how your panels are connected (in series or parallel), if the VOC exceeds the machine’s acceptable range, there is a risk of burning the unit. Therefore, please strictly adhere to the specified solar input VOC range for your BLUETTI.