You need to remove the battery, charge it, and refit it. As for checking the charge rate, if you don't know what you are doing, without meaning to be offensive, it would be best to have a garage do it, as I believe you have a smart charge system. As for the drain test, it is merely a matter of disconnecting the negative cable from the terminal on the battery and connecting an ammeter between them. With everything switched off, you should not get a reading of above 0.2 - 0.3amps.The lower the better.