Parasitic Draw

[sdb999]

2001' 82k miles
20 minutes sleep time, multiple cycles, same result. This looks like a parasitic draw to me. Car is closed, but not locked, trunk latched but open of course. My only hope is I'm reading my meter wrong as I rarely use it for current.....this is 430 mA correct?
Thanks, S.

meter.jpg

[Manny G.]

430ma is fine, not worth worrying about. If it were above 1A, then you would have something to worry about. Just about all the E39s and E38s i check have anywhere from 370-500ma draw.

[sdb999]

Thanks for the quick reply. So I'm reading my meter correctly? My two month old battery went dead in seven days, and I thought 50 mA was typical hibernation draw. I've never wanted to be wrong so bad in my life. About to head out on 12hr road trip, not a show stopper but would like to know.
Thanks again.

[Manny G.]

anything down in the mA range isnt much to worry about. I'm pretty sure its relating to an LED light or something that is getting power (maybe nav computer? radio?) which is causing the small draw.

[chemmech]

the unit of measure selected is milliamperes so 04.3 milliamperes .... set the meter to amperes or 20A DC selection and see what the readings is to verify it reads 0.43 that = 430mA ... your manual states that the reading is up to 200mA at the 200mA selection and won't read above or to 430mA at that selection from what the manual has stated.....

"For current measurements up to 200mA DC, set the function
switch to the 200mA DC position and insert the red test lead
banana plug into the uA/mA jack," from the 410 extech manual.

[sdb999]

Yes, changing the range selection moves the decimal point to .43 when on 20A scale, then back to 4.3 on the 200mA scale. So I’m guessing because we are out of range on the 200mA scale those readings are meaningless. Good to know, as I lost the manual years ago.

I have been using the 20A scale most of the time and initially it will read 4.0 - 5.0 amps then quickly drop down to 1.5 or so in a few minutes, eventually when I return (20 minutes later) it has consistently bottomed out at .43 on the 20A scale. We have 430 mA then confirmed at full sleep mode. Now, Manny G says this is quite common, Timm’s experience is different by a factor of 10x http://www.meeknet.co.uk/E38/E38_Battery_Drain.htm
and mentions a draw of 500 mA will drain a battery in seven day, which is exactly what happened on mine.

Manny G mentions possibly an led or light left on, and I do have a single led that is lit on my radio/nav unit for no apparent reason. I’ve come to ignore it but I’ll go check if it’s on with key out doors closed.

[chemmech]

yeah looks like it's 430mA I use autorange dmm's so this is sort of new to Me odd the way the scale worked out wonder if it's due to the jack the plug is in, proper though since amps are up and down into the 4.0-5.0 range careful with that sort of draw if it's constant though up to or past the 7 days.....

[Manny G.]

Yes, changing the range selection moves the decimal point to .43 when on 20A scale, then back to 4.3 on the 200mA scale. So I’m guessing because we are out of range on the 200mA scale those readings are meaningless. Good to know, as I lost the manual years ago.

I have been using the 20A scale most of the time and initially it will read 4.0 - 5.0 amps then quickly drop down to 1.5 or so in a few minutes, eventually when I return (20 minutes later) it has consistently bottomed out at .43 on the 20A scale. We have 430 mA then confirmed at full sleep mode. Now, Manny G says this is quite common, Timm’s experience is different by a factor of 10x http://www.meeknet.co.uk/E38/E38_Battery_Drain.htm
and mentions a draw of 500 mA will drain a battery in seven day, which is exactly what happened on mine.

Manny G mentions possibly an led or light left on, and I do have a single led that is lit on my radio/nav unit for no apparent reason. I’ve come to ignore it but I’ll go check if it’s on with key out doors closed.

Timm's link references lots of the components relating to the navigation and phone system. Yeah 7 days without starting at that draw might make an aged battery die... but if its relatively new, it shouldnt. Try disconnecting the nav system or phone modules and measuring again. Timm's site has excellent troubleshooting steps.