So my wife has on 06 ml500 runs great no problems. then sitting at a fast food parking lot for a while radio on went to leave battery not strong enough tow service came out
got a jump no problem. Next day went and had a battery put in checked for charging 14.X volts good. Went home my wife turned the car off maybe 2mn got my son and left gone maybe 15mn came back about 30mn went to leave crank but no start?
please help. thanks Larry

 

Hello and welcome to the forum! How old is the battery? Test the alternator to make sure that the battery is able to keep the charge.