Is Portuguese permanent residence permanent, or do I still have to renew the card?

Permanent residence under Article 80 has no time limit on the status itself, which is its main advantage over temporary residence that must be renewed on shorter cycles. You no longer need to satisfy the temporary-permit conditions repeatedly.

However, the permanent residence card is a physical document with its own validity, so you must renew the card itself when it expires and keep your registration details current with AIMA. Renewing the card is an administrative step and is different from re-qualifying for the status.