FWIW, I replaced the battery on my 2005 (12/04) X5 4.4i (N62) with a Deka AGM battery. No problems from the new battery (from my incompetent install, well, that's a different story…).

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Kirk
Las Vegas
2016 X5 40e Mineral White/Black Dakota Leather, ZLL, ZCW, ZDA, ZDB, ZPP, multi contour seats, rear side window shades, HK stereo
2011 E90M3, 6-speed manual