The recent manufactured cars would not use conventional keys to open the door. It will need to have a remote access key. While it is providing easy access to a wheel, it would also provide you a trouble to get in.
What if the remote access key lost its power, then the remote key is no use. The life time of battery is around 2-3 years and the smart car will indicate you about the low battery of remote access key. Then, the easy and simple way is bring your car to service center or dealer shop to replace old batteries in order to avoid further troubles. It would cost you around $20-$30 from professional service. But if you are brave enough to open remote access key, then it would cost you only few $.
First, open the key or check the owner’s manual to know correct type of battery.
Second, buy a battery from ebay or any online shopping mall to save money. This is painful to wait but will save you few more bucks.
Third, replace a battery with new one and try it on. You should not see the warning sign or indication of low battery of remote access key.
Simple and Easy to replace batteries for the remote car access key!