Solar panel diodes

I have installed 2 x 100watt solar panels with an MPPT controller and it works fine, however I read somewhere that diodes are recommended to protect the battery from being discharged under certain circumstances. From what I have read so far it seems that Schottky diodes are the better bet.

So for 2 x 100watt panels would a pair of 45v 15 amp Schottky diodes be up to the job or if not what would be the appropriate size

Thanks in advance
Phil