Hi, my sailboat will throw shadows on the 6 100 w panels, and Sunpwer warns not to connect them in parallel. I bought 3 Victron 75/10 mppts, and plan to try using first just one panel per c.c., joining the outputs from these 3 c.c.s at bussbars, feeding 3 Epoch 105 amphr LiFePo housebank, connected in parallel. I have read that this c.c. needs at least 5 volts more than the batt. voltage, which is 13.2v.. Could I solve this issue by using 2 panels in series for each mppt, thus doubling the voltage in?Shading issue on sailboat solar array
Yes, exactly that.
Thank you, Justin, for your kind indulgence of my aspirations, but why I doubted the practicality of upping the voltage in this way was the report of others, who lament that shading shuts down most of the voltage - or is it amperage ? - when a string is connected in series. It would then appear that only if I had purchased shade-tolerant panels ( “with 16 busbars, and multiple bypass diodes”) would the above iteration work. I should however also mention that my boat uses only 30 or 40 amphrs/day, so maybe I should go ahead as you have encouraged, and log back in when I have some results. Thanks again.
Bypass diodes! Your series panels will work better. One gets shaded, bypass diodes kick in and allow the other to work.
That would usually be why sailboat owners have multiple small controllers, as you do. Sure, when one set of panels is shaded the output of those panels will drop (that’s unavoidable) but the other 2 sets of panels on their respective controllers will still be outputting fully - assuming that you have the panel sets at various locations around the craft.