I fitted a Sterling  battery charger to my B32 several years ago and it was very straight forward. The unit is mounted in the locker adjacent to the batteries and is connected to the 240v supply via one the connections on the rear of the sockets, which were changed to UK 3 pin from euro 2 pin using straight swap units from Furneaux Riddall. The 240v supply is fitted with an in line fuse protection provides  a 30amp 12v supply when plugged into the mains in port. Saving the batteries from draining. The system was straight forward to fit and had worked perfectly for the past 6 years. I also fitted a galvanic isolator to the shore power socket on board to protect the anodes from excessive depletion.