My battery is dying after 2 days of no usage. The following is what I did to troubleshoot. Please let me know if you see anything I didn't.

Installed multi-meter in series with battery.
Steady state shutdown load on battery (SS S/D) ~130ma.
Expected normal SS S/D current draw ~25ma.
Started with 860ma immediately after closing all doors.
Lowered to ~197ma after ~25 secs
Began pulling fuses, one at a time.

In the engine compartment, driver’s side fuses 43-65
• No current reduction when pulling fuses under hood (43-65).

In the cockpit, driver’s side fuses 21-42
• Immediately after opening door ~990ma
• With the computer display off ~814ma (~176ma load by computer display)
• After pushing door button, to simulate door closed, the computer display off ~792ma.
o With door button depressed, simulating door closed, load didn’t lower to expected SS S/D voltage.

• Pulled 30a fuse #21 (central & convenience locking, mirror heater & adjustment, power windows, remote boot/trunk release, driver seat adjustment, switch illumination) from 814ma to 720ma  94ma.
• Pulled 30a fuse #22 (central locking, mirror heater & adjustment, power windows, passenger seat adjustment, switch illumination) from 814ma to 738ma  76ma.
• Pulled both fuses 21 & 22 from 814ma to 644ma  170ma
o Individually pulled, fuse 21 & 22 add up to load when both pulled.
• With fuses 21 & 22 pulled, closed door from 795ma to 644ma  19ma load from door open.

• Pulled 30a fuse #29 (driver seat adjustment, steering wheel adjustment) from 644ma to 600ma  44ma
• Pulled 30a fuse #34 (passenger seat adjustment) from 600ma to 555ma  45 ma
o Fuse 29 & 34 similar in load.

• Installed fuses 21 & 22, leaving fuses 29 & 34 out = 725ma, door open & 705 door closed  20ma load from door open.
• With fuses 21, 22, 29 & 34 pulled = 555ma  total load from all 4 fuses ~259ma.

• Pulled 15a fuse #41 (airbag warning lamps, automatic heater system, A/C blower motor, central locking-interior switch, hazard warning flashers, heated rear window, rear head release, switch illumination) from 555ma to 514ma  41ma.
• Pulled 7.5a fuse #42 (airbag warning lamps, instrument cluster) from 514ma to 114ma  400ma
• All fuses installed, except 42, with door open 138ma; with door closed 116ma (again 22ma due to door open)

In the left side of the boot (trunk area)
• With the trunk closed 116ma; with the trunk open ~200ma  ~84ma cycling trunk release light.
• Pulled 25a fuse #9 (Convenience locking, dome lights, switch illumination) from 200ma to 100ma.
o With trunk closed, no change was observed.
• After reinstalling fuse 9, battery load remained at 100ma.

• All fuses installed and doors closed ~130ma load on the battery
• Battery disconnected voltage is 12.11vDC at 1730.

Boy, I'm sure glad I didn't read all that info and then find out there is no car or model info. Of course at the first mention of data I had to look for the car, after all what good is specific data without knowing what car.

Wild guess says the Body CAN is staying awake.
http://www.mercedestechstore.com/pdfs/507%20Systems%20I/507%20HO%20CAN%20B%20(ICC)%2010-28-02.pdf

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

...LOL


..even got the specific gravity in there.

too much data/ not enough data..

Sorry...The car is a 2002 C230K.
The other forums that I frequent are usually model specific.

With the battery voltage at 12.11, no specific gravity reading neccessary...

At 130 mA, we're talking about 6 A-hr charge drop in 2 days. This should NOT be killing the battery. Also, 12.11 V after a rest is too low a voltage - battery is almost dead. I'd be looking at either a bad charging system or bad battery, and taking measurements for this likelyhood.

Steve

__________________
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7

The battery is a Sears Die Hard. I feel the voltage is low since it had been sitting for a day already before testing.