Battery drain issue - F30 losing charge overnight

about 2 months ago· 19 posts

My F30 battery keeps dying overnight. Had the battery tested and its fine (2 years old, AGM). Something is draining it. Ive tried: - Checking for lights left on - Disconnecting aftermarket accessories - Checking trunk light Still drains. How do I find the parasitic draw? Do I need a multimeter or can ISTA show whats drawing power?

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Replies (2)

SuspensionPro

about 2 months ago#1

Use a multimeter to measure parasitic draw. Disconnect the negative battery terminal and put the multimeter in series. Normal draw should be under 50mA. If its higher, start pulling fuses one by one to find the culprit.

11 posts · 0 rep

BimmerFreak

about 2 months ago#2

common culprit on F30 is the comfort access module. it can stay awake and drain the battery. try disabling comfort access temporarily to see if the drain stops

13 posts · 0 rep

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