[PierreC]

The original factory fitted battery in my '10 XC60 T6 lasted 5 years before needing replacement.

That battery (#2 - Volvo branded, fitted by dealer) lasted 20 months.

Replacement battery (#3 - also Volvo brand, fitted by dealer) lasted 28 months and had just failed. One day the car was fine - no starting problems - and the next morning it was completely dead. Overnight charging did nothing - seems like internal failure.

Replacement (battery #4, Volvo brand) was fitted at home by the dealer. They took the car into the workshop and ran all the charging and leakage tests - and gave it a 100% clean bill of health.

So why is it that the original factory fitted battery lasts 5 years and the replacement batteries only about 2 years?

PS this is my 5th Volvo that I have owned for longer than 5 years, and in every single one of them the factory fitted battery lasted about 5 years!