Your charging system is fine. Don't worry about it. Concentrate on the battery first - when that problem is fixed - then we can go on and see if there is a current draw draining the battery. First things first. Get the charger and do what I suggested in my previous post. Once we have a good battery that is disconnected - then we can connect it and keep on troubleshooting if required.
Morris

Where can I buy one of these and how much should I expect to pay?

Could not find one like my old trustworthy charger that I use but found two to give you a guide line as to what to look for on the internet - I am NOT recommending the supplier - just suggesting to look at the charger types and rough cost ideas.
1) once problem is fixed - to keep your battery fully charged on a little used vehicle
look at : http://midwayautosupply.com/detailedproductdescription.asp?3298

2) To get a safe charge into a dead or weak battery withour overcharging in case you forget you have it hooked up- look at: http://midwayautosupply.com/detailedproductdescription.asp?3300
This will give you an idea of what to look for.
Morris

Thanks for your help on that, I will look into them. I just got a call from the shop (my car was in getting an oil leak fixed) and he said for sure it is the battery. I'm taking it back tomorrow. Hope that was the problem. I'll let everyone know.
Thanks
Kimm

One things I would definitely do is check each connection between the alternator and ground, battery, or anything else it connects to.

On my BMW 320i, after I had an alternator shop install a new alternator, the car would run fine but the battery wasn't getting a charge. I remember the VM showing that the battery was getting about 13.85vDC.

It turned out that the person who installed the alternator didn't tighten down the grounding wire on the alternator, so there was only enough current to keep the ignition and lights going. I tightened the nut and it has worked perfectly for 20,000 miles.

Well?

I am soooo sorry It's been days, I was not able to log in for some reason. Well good new's guys. IT WAS THE BATTERY!!!!That simple. It really makes me mad that they tested it and said it was fine. I had the shop test it again and they said it has a bad cell. So I returned it to the battery store, put a new one in and YEP! you guessed it. Sorry for having everyone bangin heads on this for me. But I gotta say I sure felt like I had a friend in this site. Or should I say several. Now we got that taken care of and the cat. converter changed in the mL things are looking better. I have already put 200 miles on the sl sinse the new battery. She is sooooo happy. Now I need to find out why my srs llight is on. Someone mentioned that a seat bet sensor could be bad? How can I check this?
Kimm

Great! - the static voltage test of 11.8 volts was right -the battery was toast. I would still reccomend you get a maintainer battery charger and leave it permanently hooked up to keep your new battery fresh - no matter how little you drive your car.
Morris

Don't fret over the SRS light. Use your seatbelts and solve that problem when time and budgets permit. Enjoy your SL...

Alrighty, the battery problem is fixed, now let's try a for a freebie. Not guaranteed to work, but often does on dirty/sticking contacts.

For giggles try giving the horn an authorative application. Do this in the upper right corner of the horn pad (with the steering wheel straight). Don't be shy, give it a good thump with the palm of your hand and lay on the horn for a second or two. Once and a while the SRS light will come on and stay on and judicious application of pressure to the horn pad frees up the contacts (the sping loaded contacts are the only part I didn't replace when I rebuilt my SRS system). The contacts get plenty dirty and caoted with a fine black dust.

About the only folks it may bother are the neighbors...so don't try it late at night or early mornings on the weekend.

It the lamp doesn't go out, then it could be the seatbelt contacts.

Mike, I will give it a try and get back to ya later. I gotta tell ya I have moved my landrover over so I can get the sl in and out of the garage. I've been drivin her every place. Thanx