Original 2009 Varta Battery still kicking

[AntonV]

I've had the original varta battery on a tender since I bought the car in 2009. Only 13k on the car currently. Amazingly, the battery window still shows a green indicator. What do you think? Change it anyway or keep going?

My battery tender seems to cycling in an out of charging lately. Trying to figure out if my tender is on its way out. Is there a voltage reading in the instrument cluster menu?

If I do replace the battery, what is everyone swapping to? I'll handle the reprogramming via OBD2 tool.

[NorthernDancer]

Do nothing; I have my original battery on my 2008 and for the last 12 years it sits in storage for 5-7 months of winter storage, on a Deltran Battery Tender.

[krhodes1]

Batteries that live on tenders live forever. I have a friend who got nearly 20 years out of the one in his Mom's Saab 900 after she mostly stopped driving. He would drive the thing about once a month, otherwise sat on a tender.

I got nine years out of the battery in my 328!, and I bet it would still be fine if one of my idiot housemates hadn't accidentally unplugged the tender over the winter a couple years ago. After sitting for 4-5 months it was unrecoverably dead.