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Old 12-31-2012, 02:13 PM
MP3_E46's Avatar
MP3_E46 MP3_E46 is offline
Code/wrench Monkey
Location: South Denver
Join Date: Oct 2003
Posts: 1,128
Mein Auto: Carefully
Car draws ~0.5 Amps even when locked until standby mode arrived. At 11 mins I was worried to see it still read ~0.5A, but by the time I'd returned from an errand run (different car!) the reading fluctuated between 10 and 20mA in sleep mode. Obviously the multimeter is in series with the battery.

Walking up to the car with the CA Fob did not do much. It read 0.02 (20mA) more often 0.01 (10mA). Touching the CA handle skyrockets amps -probably beyond the meter's (20A) range- but it soon settles to ~16A with the headlights on and 6A with lights off. Within two minutes it's down to 0.74A. Within 29 minutes it was down to 10mA. Conclusion: Sleep mode works fine without having to lock doors.

I'll update what it eventually falls to with the doors left unlocked and CA Fob in the house.

This is my multimeter from secondary school A-Level Electronics, I did not want to risk damaging it in mA mode so used A mode hence it reads 0.01 for 1mA. Modern ones may have overload protection, I know most auto-range these days.

Hope this info and pics assist other debugging battery/electrical issues. This a 2009 Non-nav, non I-Drive E93 but has Bluetooth (I verified Bluetooth sleeps down too by using the phone; its Bluetooth could not see the car).

At this point my theories are
1. Without registering the battery it does not charge correctly
2. Something is faulty with the charging system
3. My short commute can significantly drain the battery in three or four days

1 sounds unlikely to me but guess I'll order a BavTech and try it first. 3 seems highly unlikely unless there is a massive current drain when running.
Anyone have other theories? It has a new battery and new IBS module.

The alternator is presumably strong as once the rough running was over with the original battery the car ran fine; i.e. the alternator kicked out enough power to run the car.
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Six Euro Deliveries since December 1998 (Owned E46, E90, E91, E92 and E93)

28 vehicles in 26 years of driving so far. Guess I like cars

Last edited by MP3_E46; 12-31-2012 at 03:12 PM.
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