battery dead

fdc · 10-22-2011, 03:19 PM

I drove home yesterday night, parked, turned off the engine and I forgot the
key inserted for about 2 hours. During this time everything (radio, lights etc
was off) but when I went back to remove it the battery was completely dead.

I jumped it to another car, started no problem, and drove it around the block.
This morning all was normal and the car started just fine.

what is happening? what is discharging the battery so quickly?
Did I damage anything?

thanks a lot

fdc

bumere90 · 10-23-2011, 01:07 PM

Start the car and check the voltage
How old is your battery?

John 070 · 10-23-2011, 01:13 PM

I've been thinking about getting a new battery just because it's 5 y.o. But my car just sat about 3 weeks and it started up first try, not sure if I need to. But it was about 60F, things will be different at 20F.

Wires · 10-23-2011, 03:53 PM

Typically, you kill a battery 1-2 times (stone dead), and it's pretty much toast. If it's 5 years old, you should swap it now. It could have a plate shorting inside that can cause a power failure like that as well.

tibra1 · 10-23-2011, 04:18 PM

I am in the same boat..my battery is 5 yrs old and it struggled a bit when sitting for a week or so..but always starts up.I also noticed the "eye" on it is not green anymore its black.

I am gonna just prolly replace it and register it w the BT tool..I dont think its gonna hold up thru Northeast winter..better safe than sorry

fdriller9 · 10-23-2011, 04:26 PM

Quote:

Originally Posted by tibra1

I am in the same boat..my battery is 5 yrs old and it struggled a bit when sitting for a week or so..but always starts up.I also noticed the "eye" on it is not green anymore its black.

I am gonna just prolly replace it and register it w the BT tool..I dont think its gonna hold up thru Northeast winter..better safe than sorry

Black just means it's discharged. Yellow is when a cell is dead. Green is when it's charged.

tibra1 · 10-23-2011, 04:40 PM

Quote:

Originally Posted by *********

Black just means it's discharged. Yellow is when a cell is dead. Green is when it's charged.

Really?..I am gonna have a look at it now and see if its still black I have been driving it all weekend so by ur theory it should be green now?

fdriller9 · 10-23-2011, 04:50 PM

Quote:

Originally Posted by tibra1

Really?..I am gonna have a look at it now and see if its still black I have been driving it all weekend so by ur theory it should be green now?

Unless you keep a tender on it, it will probably be black if it's old.

fdc · 10-23-2011, 06:37 PM

you are correct the battery is the original but it works without esitation even in the
cold chicago winter. What I did this time is to forget the key inserted after I tuned off the engine. After jumping it recharged very quickly and is now OK. My question is what
is drawing current when the key is left in ?

fdc

mike3000fl · 10-23-2011, 07:21 PM

basically the car is a computer, it wont go to sleep until you remove the key.

once the key is out, the IBS monitors battery voltage and will make sure the car doesn't disharge below a level required to restart it. if it drops below this threshold, it will wake up the DME so that it can shut off things that are drawing power.

details on pg 10 on the attachment.

it's all dependent on taking out the key though.

tibra1 · 10-23-2011, 09:26 PM

Quote:

Originally Posted by *********

Unless you keep a tender on it, it will probably be black if it's old.

I just pulled it out and looked at it the eye was green..FYI pulling and re-installing this battery is a major PITA..the e46 battery are sooo much easier. My back and neck are paying the price right now

fdc · 10-24-2011, 04:31 PM

thank you Mike this very very useful

Quote:

Originally Posted by mike3000fl

basically the car is a computer, it wont go to sleep until you remove the key.

once the key is out, the IBS monitors battery voltage and will make sure the car doesn't disharge below a level required to restart it. if it drops below this threshold, it will wake up the DME so that it can shut off things that are drawing power.

details on pg 10 on the attachment.

it's all dependent on taking out the key though.

fdc · 10-26-2011, 09:09 PM

Did any of you tried the BMW Genuine Factory Advanced Battery Charging System ?
http://batterytender.blogspot.com/20...110406881.html

mike3000fl · 10-26-2011, 09:16 PM

Quote:

Originally Posted by fdc

Did any of you tried the BMW Genuine Factory Advanced Battery Charging System ?
http://batterytender.blogspot.com/20...110406881.html

it is one of these with a bmw sticker on it http://batterytender.com/battery-ten...-at-1-25a.html

fdc · 10-27-2011, 12:38 AM

thanks! I am going to get this then. I found it also on Amazon for
a lower prize:
http://www.amazon.com/Battery-Tender.../dp/B00068XCQU

Quote:

Originally Posted by mike3000fl

it is one of these with a bmw sticker on it http://batterytender.com/battery-ten...-at-1-25a.html

10-22-2011, 03:19 PM	#1
fdc Second Lieutenant 24 Rep 217 Posts Drives: E90 325xi Join Date: Sep 2005 Location: Chicago iTrader: (0)	battery dead I drove home yesterday night, parked, turned off the engine and I forgot the key inserted for about 2 hours. During this time everything (radio, lights etc was off) but when I went back to remove it the battery was completely dead. I jumped it to another car, started no problem, and drove it around the block. This morning all was normal and the car started just fine. what is happening? what is discharging the battery so quickly? Did I damage anything? thanks a lot fdc __________________ 325xi, leather. Departure: Bremerhaven Sept 28, 2005 Vessel: Franconia K-line (http://www.kline.com/PCC-RoRo/schedu...ticshuttle.asp) Arrived at the Port of Charleston at 04:40 on Oct. 10, 2005 Arrived At VPC: 10/11/05 Left the VPC: 10/14/05 3:40pm Arrived at the Dealer: 10/15/05 3:00pm Delivery: 10/18/05 10:00 am
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10-23-2011, 01:07 PM	#2
bumere90 Grozniy 195 Rep 2,602 Posts Drives: Carless Join Date: Jan 2009 Location: FL iTrader: (12)	Start the car and check the voltage How old is your battery? __________________ -fatman
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10-23-2011, 01:13 PM	#3
John 070 Lieutenant General 1751 Rep 14,825 Posts Drives: 335i cpe Join Date: Oct 2006 Location: ZSP/ZPP/ZCW iTrader: (0)	I've been thinking about getting a new battery just because it's 5 y.o. But my car just sat about 3 weeks and it started up first try, not sure if I need to. But it was about 60F, things will be different at 20F.
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10-23-2011, 03:53 PM	#4
Wires Major General 2001 Rep 5,442 Posts Drives: 2016 340i xDrive Join Date: Apr 2008 Location: Calgary iTrader: (0)	Typically, you kill a battery 1-2 times (stone dead), and it's pretty much toast. If it's 5 years old, you should swap it now. It could have a plate shorting inside that can cause a power failure like that as well.
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10-23-2011, 04:18 PM	#5
tibra1 Banned 132 Rep 6,773 Posts Drives: 2011 ZCP M3 - 2007 335i crashd Join Date: Apr 2009 Location: NYC iTrader: (4)	I am in the same boat..my battery is 5 yrs old and it struggled a bit when sitting for a week or so..but always starts up.I also noticed the "eye" on it is not green anymore its black. I am gonna just prolly replace it and register it w the BT tool..I dont think its gonna hold up thru Northeast winter..better safe than sorry
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10-23-2011, 06:37 PM	#9
fdc Second Lieutenant 24 Rep 217 Posts Drives: E90 325xi Join Date: Sep 2005 Location: Chicago iTrader: (0)	you are correct the battery is the original but it works without esitation even in the cold chicago winter. What I did this time is to forget the key inserted after I tuned off the engine. After jumping it recharged very quickly and is now OK. My question is what is drawing current when the key is left in ? fdc __________________ 325xi, leather. Departure: Bremerhaven Sept 28, 2005 Vessel: Franconia K-line (http://www.kline.com/PCC-RoRo/schedu...ticshuttle.asp) Arrived at the Port of Charleston at 04:40 on Oct. 10, 2005 Arrived At VPC: 10/11/05 Left the VPC: 10/14/05 3:40pm Arrived at the Dealer: 10/15/05 3:00pm Delivery: 10/18/05 10:00 am
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10-26-2011, 09:09 PM	#13
fdc Second Lieutenant 24 Rep 217 Posts Drives: E90 325xi Join Date: Sep 2005 Location: Chicago iTrader: (0)	Did any of you tried the BMW Genuine Factory Advanced Battery Charging System ? http://batterytender.blogspot.com/20...110406881.html __________________ 325xi, leather. Departure: Bremerhaven Sept 28, 2005 Vessel: Franconia K-line (http://www.kline.com/PCC-RoRo/schedu...ticshuttle.asp) Arrived at the Port of Charleston at 04:40 on Oct. 10, 2005 Arrived At VPC: 10/11/05 Left the VPC: 10/14/05 3:40pm Arrived at the Dealer: 10/15/05 3:00pm Delivery: 10/18/05 10:00 am
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