Originally Posted by threewirefire
The cheapest and easiest thing to start with regarding any key with comfort access is to change the battery in the remote. The key fob batteries last roughly two years, give or take. Replacing the batteries in comfort access remotes resolves 90% of the remote locking and comfort access concerns in most BMW models. They are also covered under the terms of the new vehicle warranty, so if you still have new vehicle warranty the dealer will replace them at no charge.
Did not know this, fantastic. I was milking my battery for the last few months.