re: Car battery life?

scooter lead acid batteries are good for 600 charges, about 2 years in daily use

Boat batteries that are described as marine, are mech beefed up for the pounding chop. But because of infrequent use and current leakage are good for only 24 months or so, salt water service

RV house batteries do to continuous amp usage for safety systems tend to charge and discharge and loose battery fluid , h2o. get about 3 years on them till a set blows up. Sounds like a cherry bomb, makes a mess. Use the no maintenance to avoid blowing up but still change every 3 years

Standard car batteries should be changed after 3 years to avoid getting stuck

My new Chrysler has an amazingly complex battery hook up that I read can screw the computer if not replaced properly. At three years, I will take it to a trusted battery shop for replacement.

the negative battery lead disconnect on my Harley is impossible to access.

trying to get a fourth year of use out of a standard battery is probably worth 30-40 dollars. Its not worth having to call a repair service or the wife to set up a new one in the grocery parking lot

When I used to leave my car at the Dhahran airport for a month, I would always disconnect the battery due to the salt dust and battery leakage