The "smart" charger I bought to replace the original ferromagnetic type
in the Navigator (that was cooking the batteries) was similar to this one.

Not the same brand and the one I got had 60 amps per output (3 outputs).
It was of a switching power supply design and was smaller and much
lighter than the ferromagnetic type it replaced.

http://www.enerdrive.com.au/wp-content/uploads/2016/05/ePOWER-40A-Battery-Charger.jpg