Grumpy-b wrote:The point of the non return valve is to keep the water in the circuit and not let it drain out. This has the effect of reducing the air supply which will also mean the batteries only vent one way, out through the exit and ensures both air inlet and dirt is minimised. Reducing fresh air supply does mean when a cell blows a minimum of air is present to aid the explosion. The only connection to the outside world tends to get blocked from a fresh air point of view as the pressure wave goes along the drain circuit. The internal valve may also do this but its worth taking care.
This brings me to a point which I've always wondered about, thus leaving fluid in the fill lines I wonder if during cold weather it could freeze and fracture things like the manifolds ??
I think Rob allows his to drain right out ? I've always left fluid in mine i.e disconnecting mid flow, but the freezing thing has always concerned me a little, although down here in the south we rarely see 0C or below.
ChrisB