How long should a 2004 Toyota Tacoma battery last?
If it is a quality battery it should last 3-5 years. Now if you run the battery down a few times you decrease it's lifespan. There is no way of telling exactly how long a battery will last. I have had them last 6 years and also had a few that lasted less than 2 years.
I am replacing the faactory installed battery on my 2004 V6 Tacoma today. It is just over six years old and shows no indication of being bad, I am just being safe.