[theothermp3]

For some reason, my '16 X5 xDrive35i gas 6cyl has been killing its own battery over and over for the past several days. Started seemingly out of nowhere, and I can't seem to identify why this vehicle has decided to do this. A little history here: last year around the same time give or take a month, my car started doing the same thing. Started with "increased battery discharge when stopped" warning on the dash, and eventually I found the car stone dead. Now, I don't drive it too often, maybe once every 3 or 4 days - but still well within the realm of acceptable idle time.

At that time, the battery was about 5 years old, so I got the battery changed out which seemed to fix the problem. A week later, the issue was back, so it went back to the shop. They replaced the auxiliary battery as well as they said that would also drain the main battery. Was fine for a little while, then the issue happened again. Back to the shop we go, and they run a full electrical diagnosis, energy management test, the works. They found that multiple circuits were staying active after the vehicle had shut off, but they didn't indicate what specifically.

So they did a full software update on the car. Factory reset all of the modules and basically started from scratch. Once they did that, they indicated there were no consumers remaining active during the followup energy management test. It seemed like this fixed the issue and I was free and clear. Now here we are about 9 months later, and the issue is somehow back again. Car went entire spring, summer and fall without any issues. I have another (probably very expensive) diagnostic appointment at the dealer next week.

How is this stuff troubleshot? In the olden days when things were somewhat simple, you could troubleshoot draw pretty simply using an ammeter and pulling fuses. Not sure if there is some better way to figure out what module or system could be remaining active when the car is in rest mode. I find it suspicious that the last time this happened, it was during the cold months, and now here we are getting into the height of winter again and the issue has resurfaced, although I don't know how that could correlate. At face value, it doesn't seem like the car is leaving anything on, at least nothing is obvious (water pump running noises, leds on for hours, etc.)

I attached the fault codes I pulled from the car with my scanner today when I jumped it, not sure if there is anything there of value that anyone with a better technical BMW brain than me can make sense of.