2008 Pathfinder with a 2 month old battery , kept trying to start but couldn't until battery was dead, mechanic jump started like nothing so replaced battery now and it skipped and spottered from a traffic light? Is it electrical ?? No lights were left on!!

INTERMITTENT BATTERY DRAINS ARE HARD TO FIND. TURN OFF ALL SWITCHES IN THE VEHICLE. MAKE SURE THE GLOVE COMPARTMENT LITE IS GOING OUT. OPEN THE HOOD. CLOSE ALL THE DOORS. MAKE SURE ALL OF THE COURTESY LITES ARE GOING OFF. DISABLE ANY UNDER THE HOOD LIGHTS. REMOVE THE NEGATIVE BATTERY CABLE. USE A 12 VOLT TEST LIGHT, FASTEN ONE END TO A GOOD GROUND, { METAL PART OF THE MOTOR} . FASTEN THE OTHER END TO THE NEGATIVE TERMINAL OF THE BATTERY. IF THE TEST LIGHT LIGHTS UP THERE IS A BATTERY DRAIN. IF NO LIGHT , NO DRAIN. IF THE LIGHT IS ON LOOK IN THE FUSE/RELAY BOX NEAR THE BATTERY. PULLOUT THE FUSES, LARGE & SMALL ONE AT A TIME, IF THE LIGHT STAYS ON PUT THE FUSE BACK IN TRY THE NEXT FUSE. WHEN THE LIGHT GOES OUT, THAT IS THE CIRCUIT CAUSING THE DRAIN. IF IT NEVER GOES OUT, DISCONNECT THE ALTERNATOR. IF THAT MAKES THE LIGHT GO OUT, THERE IS SOMETHING WRONG WITH THE ALTERNATOR. IF THE LIGHT IS NEVER ON, YOU MAY HAVE TO DO THIS ANOTHER DAY TO FIND THE DRAIN. ALSO HAVE THE NEW BATTERY RECHECKED.