Max Power Voltage (Vmp): 31.5 Volts
Max Power Current (Impp): 8.97 Amps
Open Circuit Voltage (Voc): 38.9 Volts
Short Circuit Current (Isc): 9.56 Amps
Ok so you aim your 280w panel at a high sun. Panel heats up within a minute or two and now you lose 10% power (because of voltage drop, not because of amps drop) so now you have actual 252W.
Lets say your wiring from panel to controller has a typical 2% voltage drop, so your input watts to the controller is now 247w.
The controller has an efficiency of say typical 95%, so you lose another 5% so your output watts is now about 235w
Amps to the battery is output watts /battery voltage. So as the battery voltage gets higher with the same watts, amps are less.
235/12.5 = 18.8 amps
235/13.5 = 17.4 amps
235/14.5 = 16.2 amps
With two panels, just double those numbers. The only reason to go series is if your panel to controller wire is thin. (To keep that loss under 3% say) Otherwise just go parallel and no diff in amps except in shade you don't lose so many.
Yes you can over-panel the Tracer 40 amper and no worries. ( I have a Tracer 2210A 20 amper--excellent controller! )
You do not need the remote for it. Save the $50 for some other task. The main unit has a display if you ever want to look at it. If you have a Trimetric, you can get the story on that pretty much.
Easiest thing to do is get a second Eco-W , one for each panel, and put both on the same battery bank in parallel. They will add their amps. That 40a Tracer is not cheap!
