Bloody Key

[LtRipley1983]

So my key doesn't work at all to lock or unlock unless it's manually done. Now I've seen on the interweb that it can be charged via a wireless charger be it phone or toothbrush, but can you not just change the damn battery?

 

[NZ00Z3]

Is it the key battery or has the key lost its synch with the car?

Look up on the web how to synch the key to the car. Give it a try fist.

 

[colb]

If its an original key it is sealed in the fob, this can be cut open to get at the battery to replace it but it has to be soldered in to the board inside. The battery should be recieving a charge when it is in the ignition as there is an induction loop around the ignition barrel that produces the charge to the battery inside the fob. There is a how to here

View: https://www.youtube.com/watch?v=I67xLKhEjWs

Replacement battery details here but showing out of stock https://www.amazon.co.uk/BMW-95-06-Remote-Key-BATTERY/dp/B00KL4ZHGM
There are firms who will refurbish your key and fit a new battery but if you only have one key that means the risk of posting it and then getting it back when its been done. Google search should come up with someone near you who offers this service.
Are you sure the battery has failed or maybe the fob has lost its sync with the car, have you tried resyncing it by using the sequence of button pushes here https://zroadster.org/threads/central-locking-not-working.39921/#post-613721

 

[t-tony]

A Z4 E85 should have the "Coffin" shaped key. I understood that they "charge" from the ignition switch. They recommend alternating between the 2 keys which come with the car?

Tony.

 

[colb]

Ooops Tony is right, didn't notice he had a Z4 2.5, so it will be the coffin shaped key, again battery is inside the fob which would need cutting open to get to it and solder a new one in. However syncing the key to the car is as per my previous post if its just lost its sync.
Firms out there that will refurbish these same as Z3's if you google to find them. If you only have one key then consider getting a second key but then you will also need the blade cut and have it programmed to the car. Been through that with mine, bought a blank from ebay that comes with the transponder in it for programming to the car, they come with a non rechargeable battery, a new one from BMW is an option but at a cost. Mobile Locksmith might be cheaper and easier as they have to read the details off the EWS system in the car and then code the new key to the car so it starts. The central locking system is a separate system on a printed circuit board inside the key fob and can be synced as previously described.

 

[LtRipley1983]

If its an original key it is sealed in the fob, this can be cut open to get at the battery to replace it but it has to be soldered in to the board inside. The battery should be recieving a charge when it is in the ignition as there is an induction loop around the ignition barrel that produces the charge to the battery inside the fob. There is a how to here

View: https://www.youtube.com/watch?v=I67xLKhEjWs

Replacement battery details here but showing out of stock https://www.amazon.co.uk/BMW-95-06-Remote-Key-BATTERY/dp/B00KL4ZHGM
There are firms who will refurbish your key and fit a new battery but if you only have one key that means the risk of posting it and then getting it back when its been done. Google search should come up with someone near you who offers this service.
Are you sure the battery has failed or maybe the fob has lost its sync with the car, have you tried resyncing it by using the sequence of button pushes here https://zroadster.org/threads/central-locking-not-working.39921/#post-613721

None of this has worked so I reckon it's a knackered battery. Not to worry.

 

[colb]

Did you try putting on a tootbrush charger overnight?

 

[LtRipley1983]

Did you try putting on a tootbrush charger overnight?

No. I have tried a Samsung watch charger.

 

[colb]

Battery replacement video here https://z4-forum.com/forum/viewtopic.php?f=34&p=1874714#p1874714