Rear Window Defogger- Bad Battery?

[RS375]

I've not seen the spec of the BMW charging system but would be very surprised if it wasn't 'smart' and continuously monitored key parameters of the electrical system.

If a low voltage was detected for instance I would expect it to prioritise which electrical loads could have the power.

[Shroom]

Bad battery/terminal connection. I had this with my X5M and they gave me the same runaround about how I need to drive it more and all that BS. Finnaly they replaced the battery and terminal connections and its ran great no errors in a year in all temps.

[MightyMouseTech]

Originally Posted by RS375

I've not seen the spec of the BMW charging system but would be very surprised if it wasn't 'smart' and continuously monitored key parameters of the electrical system.

If a low voltage was detected for instance I would expect it to prioritise which electrical loads could have the power.

You mean like shutting down comfort access, and not allowing the rear defroster to turn on.

[EldRick]

Not having the battery cable recall fixed could also potentially be giving these issues.

Bottom line: REPLACE THE BLOODY BATTERY!

[M3 Adjuster]

Originally Posted by MightyMouseTech

You mean like shutting down comfort access, and not allowing the rear defroster to turn on.

I bet a 1988 Honda isn't that smart....

[M3 Adjuster]

Originally Posted by Shroom

Bad battery/terminal connection. I had this with my X5M and they gave me the same runaround about how I need to drive it more and all that BS. Finnaly they replaced the battery and terminal connections and its ran great no errors in a year in all temps.

ooooh now that's actually an outstanding recommendation. Ok.. so it looks like the answers are...

A- Ensure battery terminals are connected to battery properly. Check battery terminal connections for corrosion.
Clean terminals and/or replace as needed. Oops... Replace anyway. It's needed!

B- Ensure battery recall has been done.

C- Replace battery!

D- All of the above.

E. None of the above. Post in another thread or begin another thread 3 months from now.

[RS375]

@M3

You've obviously gained some knowledge over the years.

For me, it's just a shame that you have to share that knowledge in such a sarcastic manner...

[markslc1]

Originally Posted by mccand

The only problem I've ever had with my car is the "low battery" warning light coming on. And the "even lower"/ car picture on lift. If the engine was off, the "low battery light" would consistently come on after about 30 seconds or less of radio playing at normal volumes.

This happened prior to my last service (July 2014). The dealer said the battery was low on charge, I wasn't driving enough, and they recharged it. (I was driving it every day, so this was BS, but I took the car back anyway)

So its still going on, and getting worse, to the point where the "car picture on the lift" warning comes up often (but not all the time).

Furthermore, I've noticed that the "touch" entry now sometimes does not work, and (worst of all), the rear defogger does not work. (even when the low battery warning is *not* present). Note that the defogger button lights up on the dash. Just no defogging. (and ONCE it *did* start to defog just towards the end of a 30 minute drive, so I suppose you could call it intermittent).

Could these all be related, and I just need a new battery? Is there some sort of sensor that disables key functions that are high power draw when the battery voltage is low?

I have an appointment with the dealer at the end of the month, but wanted to do some legwork...

thanks!

Good info here. New 1 series owner and have the following symptoms
1) Car is hard to start... but it starts
2) Low battery indicator comes on if I sit any amount of time with the radio on, ignition off
3) Rear defroster does not work even when driving
4) Car hesitates significantly under acceleration.

I looked and found my car has NOT has the battery cable recall done, so I'm jumping on that. Then I guess I need a new battery as well? I was told by the PO that the starting problem happened even though they replaced the battery a year ago. The suggestion... go drive it more. Sounds like BS.

I also wonder if the low charge would impact the drivability issue above.

[MightyMouseTech]

Originally Posted by markslc1

Good info here. New 1 series owner and have the following symptoms
1) Car is hard to start... but it starts
2) Low battery indicator comes on if I sit any amount of time with the radio on, ignition off
3) Rear defroster does not work even when driving
4) Car hesitates significantly under acceleration.

I looked and found my car has NOT has the battery cable recall done, so I'm jumping on that. Then I guess I need a new battery as well? I was told by the PO that the starting problem happened even though they replaced the battery a year ago. The suggestion... go drive it more. Sounds like BS.

I also wonder if the low charge would impact the drivability issue above.

And hopefully they coded the new battery. Could explain why it is not charging properly.

[ronster]

To OP: your battery should have been covered under warranty before your last service. Battery is warranty item and should be replaced for free especially your battery light was on

[eeghie]

What ^they said, and then there's there's the odd change your dynamo (electrical charger) and or regenerative braking charging electronics is broken.

As a general FYI: When you have comfort access and/or alarm you should expect your new condition battery to be discharged with 2 months or 3 and to for it to have damaged your battery irreparably one month later.

[Artemis]

Originally Posted by Dackelone

PS: You did have your battery cable recall done right?

Originally Posted by mccand

umm... whats the battery cable recall?
Also, any word on an "accessory" mode for radio on while car off?

Originally Posted by EldRick

Not having the battery cable recall fixed could also potentially be giving these issues.
Bottom line: REPLACE THE BLOODY BATTERY!

See issue #14 of the 1M issues log sticky:
http://www.1addicts.com/forums/showp...27&postcount=1

[eeghie]

Originally Posted by Artemis

See issue #14 of the 1M issues log sticky:
http://www.1addicts.com/forums/showp...27&postcount=1

Although it does not hurt to get it done, the battery connection to the fuse panel (~recall) is not a likely root cause for a single electrical feature to fail, nor for any battery charging issues.

[markslc1]

Originally Posted by ronster

To OP: your battery should have been covered under warranty before your last service. Battery is warranty item and should be replaced for free especially your battery light was on

I'll check with the service advisor when I get the recall done to see what they can do for me on the battery. On the positive side, some new plugs and a charge fixed the hesitation issue. We will see if the charging stuff gets handled by the dealer. Seems odd that the defroster doesn't work though.