battery drain on 2001 Mercedes-Benz S430

My s430 battery would not stay charged. One year i had it replaced, the next year-the repair shop found that the phone(that I dont use) was draining my battery. They fixed it with at $15 part and all was fine for about 7 months. Now the vehicle battery is draining again. Fortunately, the vehicle is only a Sunday driver, but I have to "jump it" everytime I want to move it out of my drive way. Now my instrument panel has gone dark. What is wrong withi this car?

Asked by for the 2001 Mercedes-Benz S430
check the generator that's what gives the battery energy, if the generator is bad it wont charge the battery:therefore it might not be the battery it could possibly be the generator. A good way to find out if the generating is generating power is by turning on the car and taking off the battery plugs and if the vehicle turns off after taking off the plugs, then that means the generator is bad not the battery.