Different wattage/voltage panels connecting to a mppt controller

[fabieville]

Is there a rule for mixing different  size panels to connect to an mppt charge controller?
I have a set of 24V panels. (6) are 320 watt and (2) is 370watt. They are all canadian solar brand.

My 60A mppt controller can accept a total of ( of these panels for charging my 48V battery bank. What i need to know is if the Vmp/Voc of the panels are off by say 1 or 2volts difference between them will this cause any operating issue from the mppt controller?
Will i still get optimum performance/tracking from it? I assume that the 370watt will decrease in wattage and perform at 320watt max will that be the case?

Please advise me as to how much difference you can have in terms of mixing panels with different open circuit voltage and optimum operating voltage and then connecting  them to an mppt charge controller and still expect excellent performance from it in regards to producing close to your overall wattage and excellent tracking ability with the different voltage strings.

[Scruff]

The lowest Imp panel in the string will be the current limit of that string. Usually it's a cost versus efficiency thing so not worth worrying about.

My 11 panel array has 7 breeds of panel.
2.5kW on a SB1700. The GTI regularly hits the input peg so I don't worry about it.

[mab]

If you're mixing panels within a string then as scruff says it is the Imp values that matter and will hopefully be fairly close.

If you're paralleling a string of 370w panels with a string of 320w panels to the input of your mppt controller on a 48v system,  then a difference of 2v between the Vmp values of the two strings won't matter. If it were a 12v system and your input voltage was around 17v, then yes, you might notice, but even so it wouldn't justify paying for a 2nd mppt controller.