Battery not charged - Black dot

[azazelus]

Hi Guys

I havent started the car for a while. It seems the battery indicates the black dot - not sufficient charge and the car is not starting.

How should i charge the battery for z4? Do i need a special charger?

3.7A slow charge will be ok for this battery? Take it out of the car and leave it overnight?

Please advice.

 

[alane29]

Try charging it first take it out or at least disconnect the cables ,in my experience dead batteries don't respond well to charging especially when they are old .but its worth a try

 

[azazelus]

But if i disconnect the cables will i loose the codes for radio, etc?

 

[Bing]

You won't lose any radio codes, it'll work fine when you reconnect the battery. You will need to re-set the clock and the one-touch function for the windows, that's it.

If you've got the original battery in your car you'd probably be as well getting a new one. The build month/year of the battery is stamped on the top or side of one of the terminals I think.

 

[azazelus]

thanks Bing

Appreciate it. How long do i have until the car goes into transport mode?

 

[Bing]

You know what, I have no idea. But I'd suspect at least weeks or months ?

 

[Bing]

A quick google turned up this thread :

http://www.bimmerfest.com/forums/archive/index.php/t-734932.html

It seems that disconnecting the battery is not the issue, it's the car sensing low voltage over time and protecting the battery by reducing power used by certain systems. If the battery is fecked and it's not been driven a while then you may find this has happened already...