I have the Sargent EC200 control system. When I hook up, trip the main switch on, I have 240 power. Question? if I turn on the red battery charger switch the electric box cooling fan kicks in, do I need this in the on position all the time or can I turn it on when needed, i.e. top up batteries if required. In the colder months I noticed the cupboard that houses the box gets quite warm as the heater is in front of it. Would it be safe to have off over summer nights as only the fridge/freezer would be on and colder nights when heater is on as well. The reason I ask is the cooling fan is so damn noisy and I have been told this the norm for this system.