Adding more solar panels

[asdex]

Hi, i have 4 solar panels running a water pump. The are two each in series then parallel up.
The specs are: 260watt Voc 39.10v, Isc 8.56A, Vmp 31.91A, Imp 8.15A.
I need to add two more for a new larger pump.
The retailer says I can put three 260watt panels in series then the other 260watt plus their two 340watt panels in series then parallel up both strings.
Specs for the 340watt panels are:
Vm 34.73, Im 9.79Amps, Voc 41.55v, Isc 10.46Amps.
Would this work OK or are the panels two different?
Thanks

[chrisski]

Without doing the math, may not be wise, but since the panel voltages are fairly close, may work. The math is I’ll tell the truth.

but reference this article towards the end the mixed set of panels in parallel.

https://solarpanelsvenue.com/mixing-solar-panels/ for the formulas.

Can you do it yes, but once panels are mixed, each set of panels in series voltage is limited to the lowest voltage of the three sets you’re talking about. Makes more sense in the diagram.

[bcroe]

I think it would work but your 340W panels would be limited to perform like
260W panels. A more productive plan would either get a third 340W panel
for that string, or 2 more 260W panels (generic and probably cheaper) in
series with the odd 260W, if that is enough power.

The above assumes you need the voltage of 3 series panels. If only 2 needed,
just keep the 260W setup and put another series pair in parallel.
good luck, Bruce Roe

[asdex]

Yes maximum current on the controller is 15 amps and 150 volts. Im just going to check with the pump supplier on that 15amp. they say 6 x 275watt panels are needed. not sure if that can be achieved.