Weird Battery Drain on 2005 X5 3.0i

[M3rocket]

Yeah, ordered a used/refurbished one yesterday.

[Road Ruler]

My former vehicle was an 03 Infiniti G35. Parasitic drain was common and it was a fault on the radio/heater control bd. PITB for sure. Glad you figured it out.

[M3rocket]

Update: As I said in October, I replaced the Radio/MID unit with a $70 used one, but wasn't completely convinced it was the culprit. The beginning of my startup problems in June 2017 was the switch from my OEM BMW battery to a AAA battery. Since I'd gotten a refund on the battery, plus visa credits, I decided to swap it out for an Interstate Megatron 85 Plus. No issues since. The installer tested the AAA battery and said it was fully charged and up to snuff, but the cold cranking amps dropped to the floor when a load was applied.

So lesson-learned: stay away from AAA batteries!

[deshyznit]

So I went through almost exactly every thing you described in this thread. My mechanic removed the radio fuses as you mentioned, no problems till like a dummy I wanted to listen to music with a friend and figured could remove a fuse from the on board computer and replace it when I'm done. But after apparently that fuse is more important than I thought because the battery completely died and won't start even after replacing said fuse🤦🏾*♂️

So I'm just alil confused at the final solution you came too? Did you replace the radio head unit, the battery or both? Because I would like to keep the original head unit since it's integrated with the dash display.

[EmrisKahn]

Hello. I'm probably a little late to these forums however I also have a BMW X5 2005 with the same issue. Something is draining my battery overnight leaving it flat next morning. I was wondering if you ever found a solution to this? Thanks.

[MIKYZZ4]

You have to put in some work,
search for the circuit causing the drain.
Once you have the circuit, you can narrow down the component.