One of the keys that came with the MIL's 116i had a flat battery die to non use. We used @[Gar]'s trick of leaving it on an electric toothbrush stand overnight to charge it back up and now it starts the car so it's still coded properly.

However, the buttons won't control the central locking. I assume it just needs to be programmed to the car. Does anyone know they procedure to program a rectangular key? I've inly ever done it with an old fashioned e39 style key.

Thanks
John