Aft replac alt i jumped. Start and go to remove cables car dies. Do i need batt

you must have run the battery all the way down,drained it..charge it with a battery charger,the alternator does not charge the battery,only maintains the charge on it..also,you may have bought a defective alternator! take the battery and the alternator to a parts store.have them charge the battery and test the alternator on their machine! hope the jumper cables were not hooked up backwards? i saw a guy do that last night,HIS BATTERY EXPLODED!!! i tried to warn him,but he said he was a mechanic and knew what he was doing? Yep,he is a gooden too!blew the tops off and blew the battery up,LOOKED REAL BAD in pieces!!! I COULD TELL,THAT'S WHY I TOLD HIM I HAD no cables,WHICH I DID,but he didn't use my battery or my cables!