I have the ctek mxs 5.0. I purchased it over two years ago just to keep the battery on my E63 fully charged. Was purchased from advice on this great forum. Thanks guys. It's been faultless. Great purchase it has been. I think it was £70/80 pounds.
I think I know the answer, but is it ok to keep the ctek attached to the battery charge points on the vehicle constantly. As I think once it reaches its full state of charge it just keeps it maintained and tops up when the ctek detects a drop in charge.