Advice please, I am new to this world and would appreciate any help available.
I am upgrading a small system on my houseboat. Currently I have 3 - 195w solar panels, 2 - 12.8v 200ah LiFePO4 batteries, Victron 100/30 MPPT
charge controller. Batteries are in parallel to support 12v system. Solar panels are in parallel as well.
I am adding two additional 195w panels and one more 12.8v 200ah LiFeP04 batteries.
Questions:
-Can I use the Victron 100/30 for all 5 panels?
-Am I better off putting the panels in parallel?
-Should I get one bigger charge controller to support?
-can I use two Victon 100/30, one for 3 panels and one for 2 panels?
I would get a 100/50 and use that on the 3x195W. Parallel is fine if they are 10A panels. The 100/30 is only good for approximately 400W at 12V. The 100/50 will allow you to go up to approx 600W, which will match the 3x195W well.
Two controllers work well on the same battery. For synchronised charging, you can set up a VE.Smart network using this Victron manual.
Series vs Parallel Connection
A series connection is ideal when:
You have long cable runs and need to minimise current
You want to use smaller-gauge wire to reduce costs
Shading isn’t a major concern
Parallel connection works better when:
Panels may experience partial shading
You want to maximise the current input to the MPPT controller
In my experience, MPPT controllers tend to perform slightly better with higher current rather than higher voltage, likely because the current levels are closer to the output side and the input voltage remains nearer to battery voltage levels.
Safety Consideration
Series connections create higher voltages. Once you exceed 50V, additional safety precautions become necessary due to increased shock hazard.
The choice ultimately depends on your specific installation requirements and constraints.