EE AND OTHER WERE CHANGING THE FEMALE BATTERY PLUG RECEPTACLE ON A SET OF #18 COAL HAULER BATTERIES. HE HAD CONNECTED THE POSITIVE LEAD AND WAS CONNECTING THE NEGATIVE LEAD. HIS RATCHET AND EX TENSION CAME IN CONTACT WITH THE BATTERY CASE CAUSING AN ARC. THE FLASH BURNED BOTH OF EE S HAND MOSTLY ON TWO FINGERS ON EACH HAND.