SRCthird

I bought my s550 about 2 years ago and the things been almost perfect aside from the air suspension and some speed sensors. Almost 4 months ago i ignored the check battery light for a little too long and the altinator kicked. Ever since replacing it I've been having some electrical issues. Almost any time I turn the car off the second the seet finishes moving forward the battery completely shuts off making the alarm, key fob, ect. stop working. The second I put the key in the ignition the battery turns back on for about 5 minutes or until I fully turn the car on. Everything will also stay on for about 5 minutes if I put the key in the ignition then pull it back out. I talked to a few people already and have been told that it might be in a type of battery limp mode, one of the 2 battery's is dead(dying) or a blown fuse. ​​​​​​ I've hears of Porche having a fuse deliberately taken out from the factory as an atitheft measure that puts out all the same symptoms I'm having but am unable to find anything on it about Mercedes. Would love to receive some input on this.