I can't believe it's this 'hard' to change a freaking battery! all my life it's just swap out the old in put in the new and voila you're in business

anyways, I bought the Carly adapter and the BMW What app for iOS so I can register the new battery, my wife's new to us X5 is a 2008 3.0si still on the original battery and I want to get it swapped out before the cold of NJ winters sets in. I don't have experience with AGM batteries other than putting one meant for snowmobiles into my e36 M3 track car since it's tiny and ultra lightweight. How can I tell which battery to buy AGM or not? I took a look in the trunk and I see the current battery does have a vent and it says 900cca on it, can I tell AGM or not without removing it and seeing if it has water in it? I want to make sure I buy the correct battery since replacing the battery in these cars is not as straightforward as my experiences with e30s/e36s/e39s/e46s and non-BMW cars

Is there any chance of the modules flaking out while unplugged? I'm also going to be replacing front right passenger seat belt receptacle while the battery is unplugged since it 'exploded' likely in the accident the car was in previously

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