Balance Checker can flag the card sometimes, all depends on the bank, some banks are nasty and do not like balance pre-auths, ofcourse this not happen with all banks but this is something we cant cotrol, if you want to check your card safely without any flag/kill risk, just use the CC/DUMPS Checker.
http://luxchecker.pm/
http://luxchecker.pw/
CC/DUMPS/BALANCE Checker.