Do I need a voltage controller / regulator? Yes, we recommend a regulator if working over our recommended minimum ratio of 10W of solar panel to 100AH battery capacity.

How do I calculate the Amp rating of the regulator needed?? Employ the equation of Amps x Volts = Watts. Therefore an 80W solar panel charging a 12V battery should be regulated using a solar regulator rated 6.7A or more.

Do I need to fit a diode?
A Blocking Diode is fitted to ensure the correct flow of current and should be fitted when either no regulator is used or more than one solar panel is connected in parallel. The diode fits directly into the junction box of framed solar panels. Marlec's semi-flexible ranges of SunWare & Spectra solar panels all have a built-in diode. Schottky Diode 8A Part Number 913-012 Schottky Diode Kit 5A Part Number CA-11/01

We offer three ranges of Solar Charge Controllers:
Steca Solsum Solar Regulators up to 100W
Steca PR Solar Regulators up to 1000W
Fox Solar Regulators up to 250W

If you are also installing a Rutland Wind Charger the HRDX Controller can accommodate up to 100W of photovoltaic panels in addition to the windcharger.