Rechargeing Key Fob

[101RRS]

Hi just got a new key fob for the RRS (D3 equiv) and it has taken a while to charge the battery. Drove 800km two weeks ago and charged it up but it has gone flat again so maybe needs to new battery - I will try to get a new one tomorrow. Car does warn me when it is low.

Just a question on charging the fob battery. With the key in the ignition will it charge when off or does it only charge when the ignition is set to ACC or Ignition?

Thanks

Garry

[BradC]

I can't find anything definitive in the wiring diagrams or electrical descriptions. The Manual 419-01B says the transponder coil is energized when the key is inserted. That's the RFID part of the immobilizer, however I'm pretty sure it's also used to charge the remote battery. I would expect like most other parts of the car though, if you left the key in eventually the system will time out and go to sleep.

I have seen many, many descriptions in the UK D3 forums of people using the old Oral-B inductive toothbrush charger to charge a key however. I can't see any of the phone chargers working because it won't be able to negotiate but the toothbrush charger is just an always-on low current inductive charger.

The other thing worth mentioning is people charging both keys at the same time in the car by sticking them together with tape or rubber bands.

[101RRS]

Thanks Brad, I figured it might be unclear on weather the key just has to be in the ignition or whether it has to be has to be turned to at least accessory. What was a concern today is that I had to unlock the car using the emergency position on the passenger door but the alarm did not go off when I opened the door even though the car was locked - I will have to look into that/

I do have an oral tooth brush charger but have not tried it as I figured it was as easier to do it in the car.

Interestingly the other fob which is now 18yo still manages to charge and keep charge after all this time but the new one has issues.

Garry

[Narangga]

Interestingly the other fob which is now 18yo still manages to charge and keep charge after all this time but the new one has issues.

Garry

Have you checked the ECB to try to determine if the battery holder has been soldered securely to the board to allow the charge to happen?

Replacing the battery and holder every time, along with the short life span I had with the batteries, caused me to change to a fixed (after the first solder) holder and then use disposable batteries, each of which last far longer that the rechargeable units.

If your second fob still has an 18 year old battery in it I'm sure the new one is very frustrating for you!

[101RRS]

Sourced a new rechargable battery today - most battery places do not sell them but the one place I normally buy all my batteries from had one. Sitting on the shelf for who knows how long, it still has the recommended 3v where as the "new battery" installed on the fob only showed 2.6v after a 30minute drive so is cactus.

I soldered on the new battery and all is good now. Oh the ignition switch has to be on ignition for it to charge the fob battery, off or accessory does not charge it.

[BradC]

Oh the ignition switch has to be on ignition for it to charge the fob battery, off or accessory does not charge it.

Very useful info, thanks. Makes sense when you think about it. The car doesn't care about the immobiliser unless it's in the run position.