Craig,

Unfortunately the marine industry has been fed a boat load of crap regarding "smart chargers". Now days everyone slaps a "smart" label on just about everything.

Some charger makers are actually kind enough to warn you, in the manual, about the POS you just purchased, most others lie/mislead by omission..

"Smart" Battery Charger Manual:
"CAUTION! 3 stage charging is recommended for charging stand-alone, unloaded batteries (there is no load connected to the battery when it is being charged). If a load is also connected simultaneously, a part of the charger's output current will be diverted to this load. Thus, the charger may remain locked in the "Boost or Absorption Mode" if the current drawn by the load is more than the preset value of threshold current determining change over between the Boost and Float Stages. This will lead to overcharging and loss of electrolyte."

FWIW a "dip switch" set charger is usually very far from "smart"..