As title, do you still remember or are you still using the factory fitted battery in your R36?

I received CTEK battery charger today and decided to give it a go. I saw it's a AGM battery in my R36, details below:
Black
Varta
AGM
7P0 915 105 C
12V 92Ah 520A DIN
850A EN/SAE

not sure if previous owner changed battery that's why I am asking. Thanks.