E90Post
 


Bimmer Retrofit
 
BMW 3-Series (E90 E92) Forum > BMW E90/E92/E93 3-series General Forums > Regional Forums > UK > UK Technical Forum > New battery?



Reply
 
Thread Tools Search this Thread
      06-08-2012, 09:21 AM   #1
sylonien
Major
United Kingdom
55

 
Drives: M3
Join Date: Apr 2012
Location: Over there


Posts: 1,215
iTrader: (0)

New battery?

My car keeps on saying battery charge low even after hours of driving or charging (CTEK charger). Took it to garage to check and they said that it wasn't charging properly. Machine said there was only 11v when the engine was on.

So could it be the alternator or just because the battery is old and dead? Have ran flat twice or so before, don't drive it that much. And the same battery since 2006.
Appreciate 0
      06-08-2012, 09:53 AM   #2
greatbm
Captain
United Kingdom
13

 
greatbm's Avatar
 
Drives: F33 428i M-Sport convertible
Join Date: Feb 2007
Location: North East UK


Posts: 812
iTrader: (0)

Quote:
Originally Posted by sylonien View Post
My car keeps on saying battery charge low even after hours of driving or charging (CTEK charger). Took it to garage to check and they said that it wasn't charging properly. Machine said there was only 11v when the engine was on.

So could it be the alternator or just because the battery is old and dead? Have ran flat twice or so before, don't drive it that much. And the same battery since 2006.
Battery will never charge at 11 volts, with engine running alternator should be producing at least over 12.5 volts and up to 14v depending on load i.e. a/con, wipers, lights etc.
Appreciate 0
      06-08-2012, 10:01 AM   #3
sylonien
Major
United Kingdom
55

 
Drives: M3
Join Date: Apr 2012
Location: Over there


Posts: 1,215
iTrader: (0)

New battery will cost me around 185 fitted from main dealer, 15 coded and fitted from specialist with my own supplied BOSCH battery.

New alternator 700+??

The guy said that it might be the faulty battery that is given the wrong reading?
Appreciate 0
      06-08-2012, 10:52 AM   #4
AlwynMike
Captain
United Kingdom
28

 
Drives: E91 335d.
Join Date: Sep 2010
Location: Shropshire, UK


Posts: 953
iTrader: (1)

I would suggest you change your supplier!

As mentioned, the average voltage an alternator kicks out is aroung 14.4 volts. Even if there is a couple of cells gone in the battery, it will still charge at higher than 12 volts. With a couple of cells gone, your car wouldn't even turn over, never mind start.

Get a proper, professional opinion on your alternator (and I don't mean main dealer here). There should be reconditioned ones available, or with some places, they will even swop the brushes or control box for considerably less. This sort of service is lesser known these days, unfortunately!

I shouldn't assume, but I hope that someone has checked the condition of your battery leads and connections - this can lead (no pun intended) to low voltage readings.

Mike
Appreciate 0
      06-08-2012, 11:26 AM   #5
Hotcoupe
Major General
United Kingdom
150

 
Hotcoupe's Avatar
 
Drives: Don't know yet!
Join Date: Jul 2007
Location: UK


Posts: 6,105
iTrader: (2)

Garage List
Quote:
Originally Posted by AlwynMike View Post

I shouldn't assume, but I hope that someone has checked the condition of your battery leads and connections - this can lead (no pun intended) to low voltage readings.

Mike
Excellent call Mike,battery leads and connections were the cause of my cars last visit to the dealer.

Apparently it's quite a common fault with the E92 (not sure about other E9x's) for the battery compartment to suffer from water ingress,this problem causes a variety of faults,a low voltage reading being one of them.

My car also on occasion suffered from losing all power with no warning,and sometimes completely cutting out all together,again with no warning.

Fortunately,it was sorted as a 'goodwill' gesture.Happy daze
Appreciate 0
      06-08-2012, 01:02 PM   #6
Dr Dave
Zummerzet Zyder Drinker!
United Kingdom
92

 
Dr Dave's Avatar
 
Drives: '06 330D Le Mans Blue
Join Date: May 2009
Location: Somerset


Posts: 5,541
iTrader: (3)

Garage List
I'd be more than happy to give you a professional 'diagnosis' (I'm ex-motor trade 18+yrs) - and you can have a listen to my ICE setup at the same time and make your mind up if you like it or not!!

I wouldn't code in a new battery,nor would I pay full main dealer prices. Priced up a battery for mine 3yrs ago and it was about 130, OEM.
Appreciate 0
      06-08-2012, 06:32 PM   #7
sylonien
Major
United Kingdom
55

 
Drives: M3
Join Date: Apr 2012
Location: Over there


Posts: 1,215
iTrader: (0)

Wow thanks for all the quick advices and response. Amazing!

Anyway, I rang up a few BMW specialists in Bristol today and they all said they can fit it for 15 (some say coding requires, some say you don't and some don't have a clue).

Either way cheaper than BMW 55 fitting + coding.

So do you need coding or not for the battery?

Dr. Dave, when have you got the time to check out my battery and I can check out your ICE? :P
Appreciate 0
      06-09-2012, 12:50 AM   #8
Dr Dave
Zummerzet Zyder Drinker!
United Kingdom
92

 
Dr Dave's Avatar
 
Drives: '06 330D Le Mans Blue
Join Date: May 2009
Location: Somerset


Posts: 5,541
iTrader: (3)

Garage List
Pretty much any time this weekend! Taking the boy swimming tomorrow thats about it.
Appreciate 0
      06-09-2012, 04:29 AM   #9
AlwynMike
Captain
United Kingdom
28

 
Drives: E91 335d.
Join Date: Sep 2010
Location: Shropshire, UK


Posts: 953
iTrader: (1)

Two schools of thought re: Battery coding -

Have the car coded with the new battery so it lasts longer.
Don't have the car coded and maybe the battery will last 5 years instead of 6 years.

Do the sums with the relative costs and factor in how long you are keeping the car.

Mike
Appreciate 0
      06-09-2012, 07:37 AM   #10
sylonien
Major
United Kingdom
55

 
Drives: M3
Join Date: Apr 2012
Location: Over there


Posts: 1,215
iTrader: (0)

Hm. I probably would like coding, this specialist said it would cost 15 including coding. Not that bad.

Dr. Dave, how about this Sunday?
Appreciate 0
      06-09-2012, 09:08 AM   #11
Dr Dave
Zummerzet Zyder Drinker!
United Kingdom
92

 
Dr Dave's Avatar
 
Drives: '06 330D Le Mans Blue
Join Date: May 2009
Location: Somerset


Posts: 5,541
iTrader: (3)

Garage List
It would have to be Sunday PM, after about 2?
Appreciate 0
      06-13-2012, 11:28 AM   #12
sylonien
Major
United Kingdom
55

 
Drives: M3
Join Date: Apr 2012
Location: Over there


Posts: 1,215
iTrader: (0)

I have decided to go for a new Battery since I'm going on holiday soon.
Any recommendations?

I want to go for a large battery (that physically fits) than the standard 74Ah one.
Appreciate 0
      06-14-2012, 06:19 AM   #13
Ant Man
Major
England
39

 
Drives: E92 M3 Jerez black / Fox red
Join Date: Jun 2008
Location: East Anglia


Posts: 1,041
iTrader: (1)

Quote:
Originally Posted by sylonien View Post
I have decided to go for a new Battery since I'm going on holiday soon.
Any recommendations?

I want to go for a large battery (that physically fits) than the standard 74Ah one.
Bosch. You'll probably find one to OEM spec online for 80.
Appreciate 0
      06-14-2012, 07:09 AM   #14
Greg330
Captain
23

 
Greg330's Avatar
 
Drives: E92 335i
Join Date: Mar 2012
Location: South Coast


Posts: 806
iTrader: (0)

My battery is pretty flat as I get low battery warning reguarly.

I have tried to charge with no joy as wasn't able to get the clip onto the terminal.

It also didn't look that easy to take out!

I guess my question is what does the coding actually do?
Appreciate 0
      06-14-2012, 07:19 AM   #15
doughboy
Major General
United Kingdom
130

 
doughboy's Avatar
 
Drives: E91 335i Sold.
Join Date: Jan 2009
Location: UK


Posts: 6,375
iTrader: (2)

You're meant to charge it from the red post terminal under the bonnet, not directly in the boot.


Op, sounds like an alternate issue for sure. Even with bad battery connections the alternator should still be running the vehicle positive at 13 volts or more even at idle.

Measure the vehicle running positive to chassis volts at the red post under the bonnet, again this will negate loose battery conns. If that is still 11 volts then the alty is shagged. Raise the revs to see if it picks up.
__________________
335i gone E63 AMG here at last!
Appreciate 0
      06-14-2012, 07:53 AM   #16
sylonien
Major
United Kingdom
55

 
Drives: M3
Join Date: Apr 2012
Location: Over there


Posts: 1,215
iTrader: (0)

Oh no man, alternator? Don't they cost loads?

I thought I'd go for a new battery to see first.
Appreciate 0
      06-14-2012, 08:35 AM   #17
HighlandPete
Brigadier General
51

 
Drives: BMW F11 535i Touring
Join Date: Mar 2007
Location: Scotland, Highland Region


Posts: 4,542
iTrader: (0)

As said, simply check the voltage (while running) at the under bonnet + terminal to - ground terminal.

HighlandPete
Appreciate 0
      06-14-2012, 08:38 AM   #18
Greg330
Captain
23

 
Greg330's Avatar
 
Drives: E92 335i
Join Date: Mar 2012
Location: South Coast


Posts: 806
iTrader: (0)

Quote:
Originally Posted by doughboy View Post
You're meant to charge it from the red post terminal under the bonnet, not directly in the boot.
I will give that a go, thank you!
Appreciate 0
      06-14-2012, 09:50 AM   #19
Mustard3
Private First Class
United Kingdom
6

 
Drives: 335d M sport coupe Evolved
Join Date: Sep 2011
Location: Essex, England


Posts: 149
iTrader: (1)

you can display your cars voltage on the dash the same method as you would display the coolant temperature, engine off and running (charging).

http://e90.wetpaint.com/page/BC+hidd...us/revision/37

Instead of scrolling to number 7 for temperature, scroll to 9 for voltage.
Appreciate 0
      06-14-2012, 10:03 AM   #20
sylonien
Major
United Kingdom
55

 
Drives: M3
Join Date: Apr 2012
Location: Over there


Posts: 1,215
iTrader: (0)

Oh wow!
Was just going to ask what to get to read the voltage. Any cheap ones around for future reference and take reading from the jump start pole under bonnet?
__________________
Appreciate 0
      06-14-2012, 10:11 AM   #21
doughboy
Major General
United Kingdom
130

 
doughboy's Avatar
 
Drives: E91 335i Sold.
Join Date: Jan 2009
Location: UK


Posts: 6,375
iTrader: (2)

Just get a cheap multimeter from halfords or b&q.
__________________
335i gone E63 AMG here at last!
Appreciate 0
      06-14-2012, 05:48 PM   #22
sylonien
Major
United Kingdom
55

 
Drives: M3
Join Date: Apr 2012
Location: Over there


Posts: 1,215
iTrader: (0)

Got a brilliant cheap from Maplin 8.99 was 20 ish.

So here is what I found out.

Battery reading engine off 12.4v
Voltage reading from engine bay engine off slightly less
Engine on, 13v ish with everything off, dropped a bit after switching on electronics. But then levelled out. So glad it's not the alternator! Really can't trust garages.

I charged my battery with a CTEK charger. Indicated fully charged but when I checked it was still showing 13.4v so it was still charging?

then when I unplugged it went down to 12.35v. Sounds normal but if I leave car on without starting engine, the low battery warning light would come on again.

So surely this means battery is dead?
Appreciate 0
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 10:14 PM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST