question

oilg avatar image
oilg asked

Wiring Solar panels to appt Controller (Bluesolar MPPT 100 / 30)

I have 6 solar panels that deliver 150W @ 18V. My battery system is 24V.

What would the most efficient solution for installation of the panels?

a) Install the 6 panels in series, generating maximum of 108V @ 8,3A

b) Parallel 2 x (3 panels in series), generating maximum of 54V @ 16,7A

c) Parallel 3 x (2 panels in series), generating maximum of 36V @ 25A

The panels are flexible and will be installed on top of a boat's canopy. I suspect that it will very rarely deliver the rated 18V, because the canopy has a slight arc.

Thank you in advance for your help

MPPT SmartSolar
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
Justin Cook avatar image
Justin Cook answered ·

Option (a) is not a viable option since that's over the input voltage limit of the controller.

Option (c) is viable, but at (best case) only 36vOC from the array in that configuration, the controller may not have consistently high-enough voltage differential between PV and battery to start charging.

Option (b) is your best bet under the given conditions.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

iammotorhomeless avatar image
iammotorhomeless answered ·

@O.ILG the higher the voltage the better for cable losses

but be mindful of the Maximum PV open circuit voltage 100V (and if you use the Victron MPPT calculator it suggests even lower)

and as PV voltage must exceed Vbat + 5V for the controller to start.
Me, I would do the 2 in Parallel (3 panels in series), generating maximum of 54V @ 16,7A

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.