How much is too much?

Hi Ken.  I am in a similar situation located just south of Manitoba with a 48v system, and limited solar power during the winter months.  Do you have the option of using wind power?  I get most of my electrical power from the strong NW winds in winter and the wind turbines often produce more power than I need to maintain battery charge.  I simply dump the excess power into heating of the residence.  Perhaps increasing your battery capacity would help?  I have doubled my battery bank and found that it helps to reduce the depth of discharge.  I also use a backup generator for extended "down" times of wind and solar energy resource.   Jon C. 

Ken, there are many variables here, but if I understand the parameters correctly, you have a solar panel power source of 8-200 watt panels which yields 1600 watts of power in full sunlight.  This would produce 33 amps of current at 48 volts.  Since your charge controller is rated at 60 amps, you could almost double the number of solar panels.  Keep in mind that there are surges in panel output when going from cloudy to full sun condition as the panels cool and then reheat (cloud effect), so you might want to add only two more of the same type of panel, instead of four and risk an overload of the charge controller.  Batteries, in my experience, are only 50-75% efficient in returning usable power to your system, but by increasing the number of batteries in the array, you increase their efficiency by drawing less power from each cell under normal load conditions.  So, in my experience, even though you are distributing a smaller charge current to each cell, and requiring more time to produce a full charge condition, you are also drawing less power from each cell and increasing the battery efficiency.   I wish you good fortune with your system.  :-)  Jon C.