The battery on my 2010 Sierra pickup is still going strong after 12 years. I have taken 6 week vacations and it starts up right away - no battery tender used.
The new cars have a built in battery monitor. Funny story about that. A nice lady I worked with bought a new VW. A few months later...
"The battery in my new car died"
"What? It's only a few months old"
"Well, the dealer told me that it has automatic headlights so I don't have to touch the light switch. They seemed to be working automatically but the dealer says I killed the battery"
She had the switch in the ON position when it should have been in the AUTOMATIC position. The battery monitor shut the lights off leaving just enough charge to start the engine. After a few months of this abuse, it croaked.
