I have a 1997 C180 Euro version and I need to recharge my battery which is in the boot at the back next to the spare tyre. Can I just plug in the 2 terminals from the recharger or should I disconnect the 2 wires or just the ground wire only? Do I have to take the whole battery out of the car? Do I have to open the top plugs to allow gas to escape if they can be opened? How long should I leave the power on safely? This battery is almost flat due to the car being on the dealer's floor for the last 2 weeks. I can only use the car on weekends and this is not enough use to recharge the battery fully. Do I have to reset anything besides the radio after this? Where is the radio code and how do I reset it? Thanks guys.