Ammeter - White with Stainless Steel BezelAn ammeter indicates the current flow through the battery charging system. A "zero center" ammeter, during chargine, shows a (+) positive reading indicating the current is flowing to the battery (charge). A (-) negative reading indicates current flowing away from the battery (discharge). Faria Performance Tips:Wiring - Due to the high current loads present in many ammeter applications, ammeters must be wired with wire not lighter than 10 AWG approved for Marine use.