I haven't used my E55 very much recently and the journeys I have made have been pretty short. Last used the car last Monday for around a 6 mile round trip and parked up. The Battery convenience function message showed for about 500 yards, then disappeared. This morning I had to visit the Doc's for another blood test (possible type 2 ) and the car started quickly, but I could tell the voltage was low. Again, the convenience message appeared and I drove off. Two miles later on reaching the Dr's surgery, the message was still there. Hmmm this hasn't ever occurred before. Had my test and came out to find the car wouldn't even turn over. Checked the belts and they all seem in place and there were no battery warning messages beforehand. So I called Mrs AMG'd and when she arrived, I used the booster cables I bought a while ago and the car started like nothing was wrong. Mrs AMG'd left the car park and I got back in the car to find all sorts of red warnings, ABS, SBC, SRS,alternator kaput and reduced braking, drive slowly. I also had no heater, lights, or indicators. The drive back wasn't fun and I have now put the battery on charge in situ. I'm hoping lack of use and short trips have just run the battery right down and the red warning messages will go once fully charged. Am I right to feel optimistic or have I got alternator/ SBC problems waiting for me when I start the car tomorrow? Three of the messages displayed and the reading when the battery was connected to the charger.