A shelf behind the batteries holds a triple diode isolator and three 50 amp West Marine battery combiners. The alternator output is wired to the input terminal of the diode isolator. All of the batteries receive their charging current through the isolator diodes and then, when sufficiently charged, through the combiners. This arrangement eliminates the problem of undercharging caused by charging the batteries only through isolator diodes and, since the combiners only come on when the batteries are near full charge, allows use of smaller combiners.
Also in this area is the shunt for the ammeter (which is located on the engine instrument panel under the top companionway step.) The 10 amp "smart" charger located in the 'kick space' under the edge of the bunk also sends its output through the shunt so it also registers on the ammeter (on the rare occasion that we get to tie up to a dock with power.)