I noticed that my car was doing the same over the last couple of weeks and turning over slower than it had in the past. On T-day it repeatedly started and stalled until on the 6th try it just clicked. I got an ABS and BAS light also. (I read later that this is one of those weird things that happen when the voltage goes below 10V.) I checked my MB maintenance free battery and discovered it required some maintenance. It was really low on water, so I added some and the car started no problem about 3 hours later.
Knowing that this absolutely could not be the end of this, I visited my local MB indy and he checked the charging system. He determined that it was charging as it should, but the battery was junk. He sells Interstate batteries, but advised me "there's no better battery for your particular car than the factory battery" He went on to say it was due to all the electrical gadgetry and the battery being inside the cabin under the back seat for this model. So off to the dealer I went, got a battery for $117 and change and installed it. The dealer even disposed of my old battery for free. Wow, what a difference. It turns over very quickly now and starts flawlessly. It took a bit of fooling around to get everything operating as it had in the past, radio code, windows, sunroof open/hold for three seconds etc. At the risk of cursing myself, all seems well for now. I wish all car problems were so easily and inexpensively resolved.
