I have a Gill battery in my Archer that's around 5 years old based on the serial #. I say "about 5 years old" because there's no log entry for when it was put in prior to my buying the plane. I contacted Gill & they gave me a rough date based on the serial #. My question is, should I go ahead & replace the battery before it decides to give up the ghost? Or, will I get sufficient advance warning that something's going wrong? I'd hate to get stuck at a remote airfield when it finally decides to conk out on me If I recall correctly my car battery seemed to doing just fine until one day it totally died without any warning - will an aircraft battery work the same way?