On the recommendation of my local dealer I've bought a Sunpower 110W panel and a Victron Smartsolar 75/10 controller. However on reading the specs and manual in detail I note that the panel is 32 cell and the controller recommends minimum of 36 and ideally 72. Is this a significant issue or not something I should be overly converned about? As an alternative for about the same price I can buy 2x Sunpower 50W panels to connect in series. Is this likely to give me a better overall output due to the higher cell count and voltage offsetting the small reduction in total power?
Battery is 12v. Usage is on boat so partial shading will occur at times, which I'm aware can be more of an issue with panels connected in series but will that be any worse for 2x 50 W panels compared to the 1x 110w panel of about the same total area? Initially we'll on the south coast of the UK but potentilly going to the tropics in due course.
Specs are
Model SPR-E-Flex-110
Nominal Power(Pnom) 110 W
Power Tolerance +6/–3%
Rated Voltage (Vmpp) 18.8 V
Rated Current (Impp) 5.9 A
Open-circuit voltage (Voc) 22.8 V
Short-curcuit current (Isc) 6.3 A
Power Temp Coeffiecient –0.30%/° C
Voltage Temp Coefficient –55.8 mV/° C
Current Temp Coefficient 3.5 mA/° C
Max. System Voltage 45 V
or
Model SPR-E-Flex-50
Nominal Power(Pnom) 50 W
Power Tolerance +/–3%
Rated Voltage (Vmpp) 17.7 V
Rated Current (Impp) 2.8 A
Open-circuit voltage (Voc) 21.5 V
Short-curcuit current (Isc) 3.1 A
Power Temp Coeffiecient –0.35%/° C
Voltage Temp Coefficient –58.9 mV/° C
Current Temp Coefficient 2.6 mA/° C
Max. System Voltage 45 V
Many thanks,
Bruce
