bad ground-not the problem
BST-not the problem
ignition switch-not the problem
There were no codes when I checked
No parasitic draw

Recapping, battery was dead one morning. Load tested it and it was bad. Replaced the battery. Tested as good before install. All was OK for that day. Next morning it started fine but wouldn't start at the alignment shop a short drive later. There were no dash or interior lights-nothing. Jump started it and drove it home. Turned it off and it started fine. Next morning it wouldn't start. Battery voltage was 9 something. I charged the battery for several hours. Turned on key and dash and interior lights and angel eyes came on normally. Tried to start the X and wouldn't even click and all lights either went out or were very dim. That was when I asked for suggestions as to what other than the battery could be the problem.

After eliminating all the suggestions I decided to charge it again. I ordered a battery and electrical system tester so I could thoroughly check the battery rather than just a load test. The battery failed. So back I go for another battery. They started by telling me it had to be something other than the battery but their test came up a bad battery. They brought me a 3rd battery and called the manager over to approve the exchange. He said the battery shouldn't have been sold to me as it won't handle the overnight electronic draw of a BMW. Not buying as that would not ruin the battery in two days. The battery exceeded the BMW battery specs and it comes up as a BMW replacement option.

Anyway, it has been 3 days with 3rd battery, the one he recommended and everything is back to normal. Problem solved.

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