Hello,
I currently have a24v system: a Victron 150/70 Charge Controller, A 24v 3,000w inverter, and 2-200ah lithium batteries powered by 4-340w solar panels. I currently have the panels wired in series-parallel. Would a series configuration for the 4 panels be more efficient? Thank you, Joe Patrick
Yes, If you controller is compatible with the series open circuit voltage.
Reasoning that I^2R losses in the array cables to the controller are reduced.
So each module would need to be <37Voc, at your coldest operating temperature.
Series will be a bit more efficient (higher voltage, lower current = less cable loss), but only if you stay within the MPPT voltage limits, especially in cold weather when Voc can rise. Your current series-parallel setup is usually the safer and more balanced option, and it handles shading better, so unless you need longer cable runs it’s fine to keep it as is.