I don't think about replacing the battery until there are symptoms. Then I get it load tested at Autozone. There is no charge. That will tell you what shape it is in and if you need to pick out a battery while you are there.

Be sure to get an equal or better replacement battery with a vent if you move ahead.

If you have any question it may not be the original battery there should be a date of purchase on a replacement battery.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas