Please note - I am not a mechanic or expert in anything.

 

I'm not sure if that sounds like the battery or just the battery but on a 21 year old car other components and parts could be tired and making the battery work harder.  A good battery fully charged, or a new battery if you need it, will help with any electrics and fault diagnostics and a poor battery or in poor condition will often hinder the electrics and fault diagnostics. 

 

Your current battery I noted was towards the bottom of the list if you're going to keep the car any length of time it'd probably pay you to buy a better battery to replace it.

 

Even a new battery needs all connections, cables, wires, including all earths in good condition, clean, secure and protected.

 

It depends on what you have on the car electric wise and how you use the items and the car but I'd expect very many years of battery life on a 2001 car, unless the charging or other parts was faulty or not in good condition.

 

Good luck.

 

Edited 30 September, 20223 yr by nta16
spelling

4 minutes ago, nta16 said:

on a 21 year old car other components and parts could be tired and making the battery work harder. 

 

Examples please.