I just purchased 3 more SP120 panels for my AC200P. I already have 3 SP120 panels, so this will make six. My plan is to connect all six panels in a single series and then to the solar input of the AC200P. This should add up to a voltage of about 120 volts – well within the AC200P range – and a total wattage of nominal 720 watts. However the wattage is never that high, and in practice should be about 600 watts in full sun, well below the 700 watt capacity of the AC200P solar input. I think it’s unlikely that the series would ever exceed 700 watts. (But what if it did???)
My question is: Is this the best way to connect six SP120 panels to the AC200P? Or would it be better for some reason to connect 3 panels in each of two series, and then connect those two 3-panel series in parallel?
I hope the question is clear, and appreciate any advice.
Yes, connection all six panels in series will work best. The higher the voltage the better the electrical transmission. The only reason you may have an advantage with two sets of three panels in series with the two series sets connected in parallel would be with partial shading. If you experience partial shading from shaddows, the set of unshaded panels would continue to produce more power when connected in parallel. In series, any shading affects all panel. I personally would connect all in series first and see how it performs since it is simpler and voltage transmits better.
Thank you, Scott. This is very helpful information. I had been wondering about the partial shade issue. Even though I might be lazy sometimes about moving the panels several times a day to optimize sun exposure, I think a single 6-panel series will be the best. It’s also the easiest and doesn’t require any cables beyond what is provided by Bluetti, though I do have a 10 gauge solar extension cable, which works fine and gives me more flexibility in placing the panels.
I have named my unit “Blue Eddy”, or just Eddy for short. So far it’s been working perfectly every day. My hope is for long-term reliability because I have no plans to buy another solgen, even though I know something “better” will certainly be available in a year or so, or less. The AC200P is right for my needs, and all it needs to do is to keep working like it is now.
I very much appreciate this website which is a great resource. I’ve learned a lot from reading lots of posts here. Thank you all for the helpful information.
Scott, I just saw another reference to your comment on “the partial shade issue”. Today I just ordered my AC200P along with three of the 200 watt folding panel arrays from Bluetti specifically because I had read that the new battery technology in the AC200P (perhaps along with some other new built-in forgiving factors) would not complicate/shut down solar charging if your array did not receive full sun on all parts of the array. In fact, I would have bought the EB240 but had read specifically about the “no shade issue” with the EB240 and suspect that it also applied to the battery technology in the previous AC200 which I believe you have. So have I made a mistake or did the shade issue apply only to the AC200 and that the new battery technology in the AC200P became “more forgiving” as I hope?
I’m sure Scott can answer more definitively. My experience is with the AC200P with three SP120 panels. You’re going to have a great setup with three of the 200 watt panels.
However, I think the “partial shade issue” is an issue with the solar panels themselves, not the battery, and it’s an issue with all solar panels as far as I know. They don’t perform well in partial shade. They are great with full sun exposure, especially if they are directly facing the sun, on a cloudless day, with the face of the panels perpendicular to the line of the sun to the panels. They will continue to perform reasonably well if the angle to the sun isn’t perfect, but even that will reduce output to some noticeable extent.
The SP120 panels I have – three wired in series (with three more to come, hopefully this week) – will lose 90% or more of their output wattage if one of the panels is in partial shade. As Scott has pointed out, wiring in parallel can overcome some of this issue to some extent. But you can’t wire three panels in parallel with the AC200P because you won’t have enough voltage to activate the unit at all. You need to have at least two panels in series, and it’s even better (voltage wise) if you have three panels wired in series. This will be the recommended setup for your situation with three SP200 panels feeding the AC200P.
My panels perform reasonably well – maybe 50% – if it is somewhat hazy. But actual shade, from a tree or building or whatever, reduces output drastically. I had a couple small solar panels in the 1970s (at $20 per watt!) and it was exactly the same then. The new Bluetti panels I have now are superior in many ways to those from nearly 50 years ago, but not with respect to partial shade. I think that’s an issue with silicon solar panels altogether. They get their energy from light, and there is vastly less light in a shady area than in direct sunlight. So in the shade the energy just isn’t there to drive the panels to anything more than very minimal output, to the extent that you can say that they “shut down” in partial shade.
Hopefully Scott will correct me where I am wrong in the above analysis.
Hey yall! This guy will help you ALOT by explaining the importance of wiring panels in series vs parallel and has helped me tremendously get a better understanding on the effects of shading on panels. @Scott-Benson is a complete badass tho and we’re extremely fortunate to have his expertise around the forum! Haha
So welcome to the community and please feel free to reach out with any questions!!
The issue of shading or partial shading is related to them being connected in series. It has nothing to do with the panels or what the panels are connected to. The AC200P is limited to 150 volts and 12 amps of current. These numbers determine how you can connect and attach panels. In your particular case, you must connect all three 200 watt panels in series.
Connecting in series is similar to one lane of traffic at a stop light with four cars in that lane. If the first car does not move (shaded) the rest of the cars are blocked as well. All four move or all four stop. The advantage of this method of road building is that you only need to make a single lane and it is simple.
Connecting in Parallel is like the same four cars stopped at the same red light but there are four lanes with one car in each lane. No matter which car is stopped, the others can still move. The disadvantage of this method of road building is that it takes a large amount of resources to build all four lanes. (thick and multiple wires in the panels, charging circuits and cables)
Series combines the voltage of each panel (ie 20+2+20 for a total of 60 volts. 60 volts is great for transmitting power over thinner wires for a longer distance. This is what you will see with three of your 200 watt panels. The only thing you need to keep in mind is to not have any portion of any panel shaded with anything (cable shadows, grass blades, leaves, objects etc) or the power will drop off substantially.
With parallel, the amps each panel get added. (10+10+10) Since the incoming amperage limit is 12.5 amps on the AC200, only 12.5 of the 30 available amps would go through resulting in less than desirable results.
Thanks guys. I guess I lead a sheltered life because I knew absolutely nothing about PV. This video was very useful. I suspect that I am going to have a wiring nightmare with these three 200 watt panels as each one is slightly longer than 7 ft and about 20 inches wide and with the limited corridor I have in my side yard for reasonably unobstructed sun will force me to run the three panels about 21 ft the long way. I have no idea what extra long wiring and connectors I am going to need to wire the three panels this way in series so that the array will be 20 inches wide by 21 plus feet long.
@Scott-Benson EPIC analogy my man!! Haha seriously that is perfect.
When’s the ol lady gonna get a GoPro and start recording you, so we can start getting you monetized for your expertise?!? I’m telling you bud, a Benson channel would take off! She can even wear her cat outfit to help pump up the views!!
Accepting all that’s been just said, I am wondering if I should have ordered the EB240 instead of the AC200P as all I really want is to run a roughly 100 watt air purifier for the longest number of hours during a power outage and then be able to recharge it in the shortest period of time. I am even planning on buying a second unit of either type so I can use one while the other charges. I really could use your collective knowledge on which unit I should get as my AC200P may not have been shipped yet.
@jgorran both the EB240 and AC200 are badass units but with your application, I’d think the EB240 would probably be the one you’d want to use for running that 100w purifier. And that’s because it has a lower overhead usage then the AC200 when using lower wattage items.
The EB240 solar input range (16-60Vdc/500w/10a) is much less then the AC200 (35-150V/700w/12a) so you’ve got to take that in to account as well.
So assuming I keep the three 200 watt panels, how much longer do you think it will it take on any particular day to charge the EB240 as compared to the AC200P? It’s hard to weight these pluses and minuses especially since I am going to order a second unit as well. I am leaning to ordering an EB240 so that I have one of each but I’d prefer to make a reasoned decision based upon something. Any help is appreciated. Thanks.
The AC200 is going to be nice to have on hand when you’re powering heavier usage items, such as a microwave/heater/air conditioners due to its higher wattage/increased surge inverter. It also has all the bells and whistles to power other items such as wireless charging, a killer 12v/25a dc output, and multiple items with all its increased number of AC & DC outlets.
The EB240 is just more efficient at powering the items it can (items with less then 1000w pull) because the inverter isn’t as large, and it doesn’t have all those extra options.
I’d personally go with 1 of each man. I don’t think you’ll regret it!
the new PV 200 panels should not suffer from shade from what I understand, that is, if the shade covers 10/20% of the panel surface there will be a loss of 10/20% and not a greater decrease of the connected panel , right ?