Phones used by average people on major networks like Verizon and AT&T (the carriers who support the iPhone) only keep text messages for a few days. AT&T for instance, only keeps a deleted text message for 72 hours. Verizon keeps deleted SMS messages for up to 10 days.
When you call a dead phone does it ring?
Answer: A: With a dead battery it should not ring but it should go to voicemail directly.