Changing old encryption PW possible?

[Rockadile]

I have some older external drives with short passwords.
Was wondering if I can change them without reformatting the drive?
One of them happens to be my time machine drive.

Also are the external drive encryption the same as filevault?

 

[Weaselboy]

The encryption is the same as FileVault. You can change the password in Disk Utility.

Mount the external drive and enter the password to unlock it. Then start Disk Utility and select the then encrypted partition. Now go to the File menu in Disk Util and select Change Password and follow the prompts.