Replacing battery in Key Fob - BMW 3-Series (E90 E92) Forum

DANMACINSD · 04-10-2010, 02:49 PM

Normally I would feel like a dumbass for even asking this, but does anyone know how to remove/ replace the battery in the key fob? I looked in the manual on page 38, and the picture it shows is not the same as my remote. It implies there is a little cover on the back, and there is not. Most key remotes have a little notch you can open with a dime or something. I see nothing on our key fob. The remote seems pretty tight together, I don't want to f*ck it up with my big meat skinners. Next step is to take to dealer I guess.

Flakpheiser · 04-10-2010, 05:24 PM

unless you have comfort access, I don't believe that the battery is user servicable.

onesuperboi · 04-11-2010, 06:01 PM

From what I heard, the battery in our remotes are rechargeable and it only charges when it's in the ignition of your car.

I'm not sure if your problem is with the main key or the secondary key, but whatever key you use less frequently, just put it in the ignition of your car for awhile. I'm not sure if you have to be driving or not...

DANMACINSD · 04-11-2010, 06:17 PM

You're both right, ours are not serviceable unless you have comfort access. They are supposed to be rechargeable. It hasn't done anything since that one day, we think it was RF interference.

mkaaes · 04-11-2010, 07:18 PM

It's a model 2032 battery. They're about 1.50 a piece. The back cover just pops off with a little pressure

tintivilus · 04-13-2010, 12:14 AM

Sounds like you don't have CA. Your rechargeable battery will eventually die (maybe 6-8 years) at which point you'll probably want to just replace the fob. Google E46 key battery replacement for an idea of what you'd be getting into.

mkaaes · 04-13-2010, 05:52 PM

I have CA but it's for a E92, I don't know about the E46 series. For me it lasted about 3 years

swin500 · 11-13-2011, 12:19 PM

I love how people start talking like they write owner's manuals for a living... "not user serviceable" - I'm glad the batteries in my tv remote are "user serviceable."

cole92 · 11-13-2011, 01:22 PM

I love how people bump a thread from 2010 and feel the need to insult someone on their choice of words.

Glim · 11-14-2011, 12:09 AM

Yes, the CA battery is a CR2032, same battery you would use in a desktop PC motherboard.

You pop the key out the back of your fob and use a dime and twist in the thin slot below the key hole, it pops a small cover off the bottom/back of the fob, that is your CA battery.

The battery does not charge when the fob is in the dash.

Positive plus sign faces towards you when inserting the new battery.

wildeagle · 02-17-2012, 05:01 AM

Quote:

Originally Posted by Glim

Yes, the CA battery is a CR2032, same battery you would use in a desktop PC motherboard.

You pop the key out the back of your fob and use a dime and twist in the thin slot below the key hole, it pops a small cover off the bottom/back of the fob, that is your CA battery.

The battery does not charge when the fob is in the dash.

Positive plus sign faces towards you when inserting the new battery.

Thanks to your clear and precise instructions, I was able to replace my battery with no hassles. More importantly, you saved me $50 because that's what my dealer was going to charge me to do it!

BTW, I had read the manual but it wasn't as clear as your procedure and I wasn't willing to risk damaging my key.

So thanks again. Appreciate it!

chetured · 05-25-2012, 09:56 AM

You are the only one on the thread who gave clear easy and the correct instructions - PROPS !

Quote:

Originally Posted by Glim

Yes, the CA battery is a CR2032, same battery you would use in a desktop PC motherboard.

You pop the key out the back of your fob and use a dime and twist in the thin slot below the key hole, it pops a small cover off the bottom/back of the fob, that is your CA battery.

The battery does not charge when the fob is in the dash.

Positive plus sign faces towards you when inserting the new battery.

mrmax1984 · 08-07-2012, 01:36 PM

Quote:

Originally Posted by Glim

Yes, the CA battery is a CR2032, same battery you would use in a desktop PC motherboard.

You pop the key out the back of your fob and use a dime and twist in the thin slot below the key hole, it pops a small cover off the bottom/back of the fob, that is your CA battery.

The battery does not charge when the fob is in the dash.

Positive plus sign faces towards you when inserting the new battery.

Hate to bump such an old thread, but thanks to you, I was able to resuscitate my dead, 2nd keyfob.

Duke · 08-20-2012, 08:40 PM

Seriously this should be a sticky!!

Some jerk @ the stealership swore up & down that the batteries could not be replaced so that I needed to order a new key fob.... Wtf?!?

Btw thanks for the awesome instructions the key works like a charm now

J

ENZOCOREA · 08-22-2012, 12:14 PM

sad to learn that it does not recharge

John 328i · 08-22-2012, 08:44 PM

I've been in your shoes. I actually used a exacto knife and got into the fob. I took the key to a battery dealer and he soldered a new battery in the fob. One would have thought I was a genius. IT DIDN'T WORK. Your screwed my friend. I had to buy a whole new fob. And I was screwed by the outrageous price.

Kumar_Shah · 02-24-2013, 07:57 PM

Page 35 of my manual has the directions and diagram. Doesn't specify the battery type.

Tom K. · 02-25-2013, 02:03 PM

Quote:

Originally Posted by Kumar_Shah

Page 35 of my manual has the directions and diagram. Doesn't specify the battery type.

Replace with the same battery that is currently in the fob - a CR2032. Or see Glim's post.

And make sure you observe the proper polarity.

Tom

neteagle · 03-10-2013, 01:32 PM

Good man. Appreciate the instructions.

martyp · 03-25-2013, 02:38 PM

CA fobs don't recharge in dash. Non CA fobs do.

Lifted07Duramax · 04-29-2013, 11:47 PM

How do you know if you have comfort access fob or non

neteagle · 04-30-2013, 09:38 AM

Quote:

Originally Posted by Lifted07Duramax

How do you know if you have comfort access fob or non

If you do not have to insert the key to start the car with the Start/Stop button, you have comfort access and therefore need to replace the battery when it shows in the dash that the battery is low.

04-10-2010, 02:49 PM	#1
DANMACINSD First Lieutenant Drives: 2013 BMW 535i Join Date: Nov 2007 Location: SAN DIEGO Posts: 320 iTrader: (1)	Replacing battery in Key Fob Normally I would feel like a dumbass for even asking this, but does anyone know how to remove/ replace the battery in the key fob? I looked in the manual on page 38, and the picture it shows is not the same as my remote. It implies there is a little cover on the back, and there is not. Most key remotes have a little notch you can open with a dime or something. I see nothing on our key fob. The remote seems pretty tight together, I don't want to f*ck it up with my big meat skinners. Next step is to take to dealer I guess. __________________ 13 535i Msport
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04-11-2010, 06:17 PM	#4
DANMACINSD First Lieutenant Drives: 2013 BMW 535i Join Date: Nov 2007 Location: SAN DIEGO Posts: 320 iTrader: (1)	You're both right, ours are not serviceable unless you have comfort access. They are supposed to be rechargeable. It hasn't done anything since that one day, we think it was RF interference. __________________ 13 535i Msport

11-14-2011, 12:09 AM	#10
Glim Captain Drives: 2006 330i Join Date: Jun 2011 Location: Victoria, BC Posts: 771 iTrader: (0)	Yes, the CA battery is a CR2032, same battery you would use in a desktop PC motherboard. You pop the key out the back of your fob and use a dime and twist in the thin slot below the key hole, it pops a small cover off the bottom/back of the fob, that is your CA battery. The battery does not charge when the fob is in the dash. Positive plus sign faces towards you when inserting the new battery. Last edited by Glim; 11-14-2011 at 12:14 AM.

04-29-2013, 11:47 PM	#21
Lifted07Duramax Lieutenant Drives: 2008 BMW red 335i coupe Join Date: Jan 2013 Location: springfield, mo Posts: 500 iTrader: (1)	How do you know if you have comfort access fob or non __________________ JB4 G4, VRSF catless DPs, FMIC, BMS DCI

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04-10-2010, 05:24 PM	#2
Flakpheiser Enlisted Member Drives: TiAg e90 Join Date: May 2009 Location: Nashville, TN Posts: 39 iTrader: (0)	unless you have comfort access, I don't believe that the battery is user servicable.

04-11-2010, 06:01 PM	#3
onesuperboi Major Drives: '08 e92 335i COBB 4.01 Stage 1 Join Date: Aug 2008 Location: Bay Area, CA (Alameda) Posts: 1,100 iTrader: (6)	From what I heard, the battery in our remotes are rechargeable and it only charges when it's in the ignition of your car. I'm not sure if your problem is with the main key or the secondary key, but whatever key you use less frequently, just put it in the ignition of your car for awhile. I'm not sure if you have to be driving or not...

04-11-2010, 07:18 PM	#5
mkaaes Lieutenant Drives: 997.2 C4S Join Date: May 2007 Location: seattle Posts: 419 iTrader: (2)	It's a model 2032 battery. They're about 1.50 a piece. The back cover just pops off with a little pressure

04-13-2010, 12:14 AM	#6
tintivilus Lieutenant Colonel Drives: E92 335i Join Date: Sep 2006 Location: Lake County, IL Posts: 1,826 iTrader: (0) Garage List 2007 E92 335i [0.00] 2003 325i [0.00]	Sounds like you don't have CA. Your rechargeable battery will eventually die (maybe 6-8 years) at which point you'll probably want to just replace the fob. Google E46 key battery replacement for an idea of what you'd be getting into.

04-13-2010, 05:52 PM	#7
mkaaes Lieutenant Drives: 997.2 C4S Join Date: May 2007 Location: seattle Posts: 419 iTrader: (2)	I have CA but it's for a E92, I don't know about the E46 series. For me it lasted about 3 years

11-13-2011, 12:19 PM	#8
swin500 Private Drives: 335i Join Date: May 2010 Location: Bostonish Posts: 61 iTrader: (0)	I love how people start talking like they write owner's manuals for a living... "not user serviceable" - I'm glad the batteries in my tv remote are "user serviceable."

11-13-2011, 01:22 PM	#9
cole92 Second Lieutenant Drives: too much Join Date: Sep 2011 Location: SoFlo / Tri-state / Mid-Atlantic Posts: 270 iTrader: (0)	I love how people bump a thread from 2010 and feel the need to insult someone on their choice of words.

08-20-2012, 08:40 PM	#14
Duke Lieutenant Drives: E92 335i Join Date: Feb 2008 Location: The Hills next to CHINO Posts: 497 iTrader: (2)	Seriously this should be a sticky!! Some jerk @ the stealership swore up & down that the batteries could not be replaced so that I needed to order a new key fob.... Wtf?!? Btw thanks for the awesome instructions the key works like a charm now J

08-22-2012, 12:14 PM	#15
ENZOCOREA Private Drives: 2007 335i Coupe Join Date: Jul 2012 Location: North Hollywood Posts: 71 iTrader: (0)	sad to learn that it does not recharge

08-22-2012, 08:44 PM	#16
John 328i Enlisted Member Drives: Black 2007 e90 Join Date: Dec 2011 Location: Austin tx Posts: 49 iTrader: (0)	I've been in your shoes. I actually used a exacto knife and got into the fob. I took the key to a battery dealer and he soldered a new battery in the fob. One would have thought I was a genius. IT DIDN'T WORK. Your screwed my friend. I had to buy a whole new fob. And I was screwed by the outrageous price.

02-24-2013, 07:57 PM	#17
Kumar_Shah Registered Drives: 2010 BMW 335i Join Date: Jan 2013 Location: New York, NY Posts: 2 iTrader: (0)	Page 35 of my manual has the directions and diagram. Doesn't specify the battery type.

03-10-2013, 01:32 PM	#19
neteagle Private First Class Drives: MBM 135i Join Date: Jun 2008 Location: The ATL Posts: 137 iTrader: (0)	Good man. Appreciate the instructions.

03-25-2013, 02:38 PM	#20
martyp Canada Eh! Drives: 2006 E90 - 325i Join Date: Feb 2008 Location: Moncton, NB, Canada Posts: 194 iTrader: (0)	CA fobs don't recharge in dash. Non CA fobs do.