CMPD Series MPPT Solar Charge Controller

1. Do I need a charge controller between the solar panel and the battery?

Generally speaking, it's not necessary for a charging controller or a trickle charging panel with low maintenance, such as a 1-5 watt panel. As a general rule, if the panel generates about 2 watts or less of electricity every 50 ampere hours, then you don't need batteries.

2. How big of a solar panel and charge controller do I need?                  

Multiply the number of panels by watts to get the total wattage of the solar array. Then divide it by the voltage of your battery pack to get the amperage, and add 25% to adapt to the cold temperature. At last, round up.