Well I’ve read and watched so much I’ve managed to confuse myself on how best to configure my system. The Yingli and REC panels are existing and connected. I just picked up two Aptos 440w bi-facial panels, and am trying to figure o ut how best to add these to the system. Any thoughts? I do have PV combiner cables and an Eco-Worthy combiner box, but all are in series to each AC300 at this point. I look forward to your recommendations!
Thanks GB
I see 3 options:
- parallel 2 b300 battery built in controllers to 1 Aptos panel. (x2)
CON: I like the new data tracking abilities, and this wouldn’t get counted as part of that data
- parallel the 2 Yingli arrays into a single array to a single controller, make a new array out of the Aptos to go to the freed up controller.
CON: over panelling the one array by a bit leaves a bit on the table at peak sun, but not as much as adding the new array.
- add the Aptos to the REC arrays.
CON: might be too close to 150v for comfort? Might go over 150v in cold weather. Might put stress on controllers reducing their lifespan?
You could run a 3S2P with the 6 panels on the left side of your diagram, then have all that go to one input on the first ac300. You could run those last 2 big panels in series to the other solar input on the same ac300. No harm in having a little bit of over paneling on a solar input. As long as the voltage is within spec, which it is.
How would one go about wiring in parallel, 2 b300 battery built in controllers to a single solar panel?
Just like you would parallel 2 panels to a single controller, but in ‘reverse’
Probably easiest to use 2 mc4 splitters, then the two mc4 to xt90 adapter cables.
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Thanks for the info. I was told this wasn’t possible early on in my solar days, which I now know it is. This will help my setup.
So I tried splitting and connecting my main solar line to both my AC200MAX & my AC200P. It didn’t work. The two were just bouncing back and forth, one would quickly shoot up in watts and hit the limiter and then the other would do the same. When one was getting power the other wouldn’t.
It’s not possible to connect a PV array to 2 solar chargers in parallel at the same time. One solar charger must be alone on the PV line to properly apply the MPPT algorithm and determine the midpoint between volts and amps that allows you to get the most power from the panels. Two MPPT algorithms working together on the same array would conflict with each other.
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Also please note that you should not mix different panels either since any discrepancy in voltage will be eventually dissipated (i.e. lost) by the panel feedback diodes.
Your system is actually not perfectly efficient but properly wired with different panels correctly tied together in groups.
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As @Emax suggested you could run the 6 left panels in a 3S2P configuration to MPPT #1 of left AC300 and use MPPT #2 for the 2 new panels in a 2S configuration.
Or, you could connect new panel 1 to MPPT input of left B300 #1 and new panel 2 to MPPT input of right B300 #1.
Additionally, in the future you could do both of the above to have MPPT #2 of left AC300 free for another string.
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