# BMW diamond key



## dagoo98 (Apr 23, 2004)

On the MY2000 and newer there is the diamond key where the Bmw emblem in the middle locks the door and the button closest to the metal opens the doors and the other pops the trunk. My questions is if that battery dies, is there a way to change the battery? I thought that the ignition charges the battery meanwhile the car is on but I could be mistaken. My friend says his battery in his key is dead and doesn't know how to change it or if he can change it.


----------



## Desertnate (Mar 11, 2002)

dagoo98 said:


> On the MY2000 and newer there is the diamond key where the Bmw emblem in the middle locks the door and the button closest to the metal opens the doors and the other pops the trunk. My questions is if that battery dies, is there a way to change the battery? I thought that the ignition charges the battery meanwhile the car is on but I could be mistaken. My friend says his battery in his key is dead and doesn't know how to change it or if he can change it.


The battery should charge itself while the ignition is running. I don't think you can even get to the battery like you could with the old keys. I am speculating since I have the "old" key.


----------



## ljh824 (Jul 14, 2004)

My owner's manual says if you use a key as a spare key to use it once a year to charge it up. I just looked at my key and I see no way to open it up without cutting it. I'm sure you can get a new one at the dealer. It's about $100.


----------



## dagoo98 (Apr 23, 2004)

ljh824 said:


> My owner's manual says if you use a key as a spare key to use it once a year to charge it up. I just looked at my key and I see no way to open it up without cutting it. I'm sure you can get a new one at the dealer. It's about $100.


Thanks that's what I thought.


----------



## dompa (Dec 30, 2004)

Replaced my battery for 2 days ago. Was getting a computer message about low key battery and swapped it out with a CR2016. You release a little cover in the back and then you see 2 screws and release them and replace the battery. I found some information that says ou must open the car doors remotely before you do the swap. And you must do the swap within 1 minute. Otherwise the buffered data will be gone and you'll have to re-initialize the key. Good Luck!

\Dompa


----------



## E39spd (Mar 4, 2004)

dompa said:


> Replaced my battery for 2 days ago. Was getting a computer message about low key battery and swapped it out with a CR2016. You release a little cover in the back and then you see 2 screws and release them and replace the battery. I found some information that says ou must open the car doors remotely before you do the swap. And you must do the swap within 1 minute. Otherwise the buffered data will be gone and you'll have to re-initialize the key. Good Luck!
> 
> \Dompa


That is for the older semi-circular key (not the diamond shaped, with the lock button being the rondal).

Those had replacable batteries under a bottom side access cover, the diamond ones have no access to the battery and the manual says they are rechargeable


----------



## dompa (Dec 30, 2004)

You are right. This kind should be charged while in the ignition...


----------



## Ågent99 (Jan 7, 2002)

Yes, the newer diamond style/shaped key does get charge while in the ignition. There is a small coil (inductor) in the key that pics up a field generated while the key is in the ignition that provides the energy to charge up the permanently enclosed battery.


----------



## wsu7655 (Jul 22, 2004)

*Could this be a problem in the long run?*

Most battery's have a limited number of recharging cycles. Cell phone batteries are a good example. They will only recharge so many times before you have to replace them. Could we be stuck with keys that won't work in a few years?


----------



## James (Jun 30, 2004)

dagoo98 said:


> On the MY2000 and newer there is the diamond key where the Bmw emblem in the middle locks the door and the button closest to the metal opens the doors and the other pops the trunk. My questions is if that battery dies, is there a way to change the battery? I thought that the ignition charges the battery meanwhile the car is on but I could be mistaken. My friend says his battery in his key is dead and doesn't know how to change it or if he can change it.


 How long are your drives? There was a thread a while ago about quick trips not being enough to properly charge a dead key. I did a quick search but couldn't find it. If you do short commutes you might consider a long scenic drive one day and see if that helps :dunno:.

James.


----------

