[V8] Battery question

[toml99 at todomundo.com]

The Interstate deep-cycle marine batteries that were on the boat just  
got replaced last year....one said '89!, other said '96 and they both  
still worked, but needed charging(especially the 89).  The Interstate  
battery in the Lago car was purchased in 02, and I haven't driven the  
car in 2.5 years, and it still starts once a month.....I will replace  
with Interstate