always start with the basic,s check water level if needed add distilled water only to about 1/8 inch over plates in battery.......... check all battery cables.....give each one a tug and make certain they are clean and tight.......depending on how dead they were it may be to late for them so when you charge it let the charger go till it shuts off and than check battery voltage of each battery, take notes how long charger ran and each battery voltage # and than load test the batteries and also make certain the batteries are wired correct pos to neg pos to neg.............if its tripping the breaker on charger i think your gonna find you have a battery problem.......................post all your voltage #,s and keep in mind if its a 48 volt cart that 48 volts is a dead cart each battery if good should read close to 9 volts and even at only 3 years old if they wern,t maintained they might be shot..................................