The valid range of values for PasswordMaxChar is 1-127 characters.
The lower end of the PasswordMaxChar range is subject to the PasswordMinChar limit.
The value cannot violate other password control rules, for example, if at least 1 digit, 1 special character, and a mixture of upper and lower case letters is required by other option settings, the PasswordMaxChar setting must be at least 4.
If you enter a zero or a negative value, the system replaces it with the system default value and writes an error message to the event log at the next restart.