Can I do this...

System

I have (2) 120 watt panels wired in series. I would like to add these two panels in parallel with a single 245 watt panel.

The (2) 120 watt panels in series:
Optimum Power Voltage(Vmp) 24.96V
Optimum Operating Current(lmp) 4.81A
Open Circuit Voltage (Voc) 29.76V
Short Circuit Current(lsc) 5.41A

The 245 watt panel:
Maximum power Pmax 245 Wp
Open circuit voltage Voc 37.7 V
Maximum power point voltage Vmpp 30.8 V
Short-circuit current Isc 8.25A
Maximum power point current Impp 7.96A

Will I run into problems ???

BB.

Re: Can I do this...

I assume this is for a 12 volt battery bank and a MPPT charge controller.

The panels you have listed are too far apart in Vmp/Imp (over 10% differences) to efficiently find the MPPT operating point (probably over 20% lost in power sure to mismatches).

It looks like you would need a second charge controller connected to yourbattery bank.

-Bill

System2

Re: Can I do this...

Thanks for the reply Bill. I should have provided this additional info.

It is a 24V battery system. An Outback FlexMax80 MPPT controller. Off-grid, but working toward going to grid-tie.

Based on the above, still the same advice?

Thanks!
Brian

BB.

Re: Can I do this...

Pretty much. Your array voltage should be close to at least 35 volts Vmp minimum to properly charge your 24 volt battery bank to at least 28.5 volts minimum.

-Bill