4x 22Voc panels into a 100v max controller, cutting it too close?

[Red Squirrel]

Thinking of changing my plans for a small solar setup, I have 4x 100v panels with a VoC of 22v that will be going into a charge controller that can take up to 100v.  Was going to group them in two, so 2x 44voc  in parallel, but I'm thinking I can probably get away just putting them all in series to simplify things. That brings me to 88 Voc.

Would this be cutting it too close, or should I be fine?  Under normal conditions it's not actually going to see the open circuit voltage anyway as it will be brought down from load but want to look at worse case scenario.  22 Voc is also calculated at 25C.  How much of a difference can I expect at -50C?  We don't get those temps much anymore these days, but it's still something to consider.

[fourtytwo42]

The problem is you dont know the quality of the components used in the charge controller nor the headroom allowed for, if for example it uses cheap 100V electrolytics on the input the lifetime would be short. As for the tempco my panels are specified at -0.3% per degC so potentially you could reach 102.6V@-50C if your really get those temperatures!
Perhaps you could find a charge controller with a higher input voltage rating ?

[Red Squirrel]

Already bought the controller and been using it so don't really want to buy another.     It's an Epever.  Not sure if that is a well known brand or not.  It "feels" of good quality though, if that means anything. 

Guess to play things safe I should stick to my original plan.  I figure chances are I'd be fine since there will always be some kind of load that brings the voltage down, but if for any reason something was to get disconnected, and then reconnected that's where the danger could be.

[Red Squirrel]

So had this running for a bit now.  2 groups of 2 panels in parallel then those two groups are in series.  I typically get 44 volts into the controller unless the battery is low then it might dial down depending on MPPT curve etc.  Like so far I have yet to see sun light so it's usually working under overcast conditions only so the charge controller is just sipping any available current from the panels.  Don't have much in terms of load other than the inverter and any time I turn lights on.  Can't wait to see it under actual sun light.  Maybe in January.  When it gets really cold ironicly the sun is out more.

Still need to add some monitoring and automation (low voltage shut off, outside lights on timer etc) but that will be another project. Probably go arduino based.