New Battery - DEAD - Car won't turn, slowly getting discouraged...

[AlexHart]

Hi all,

I bought my first w123 (300CD) in October '09 and put a new battery in when I bought it. I changed glow-plugs as well recently. I left the car out on the street over the Holidays for about 12 days and traveled back home to see the family. The car wasn't started at all and sat in cold, New York weather (10 - 30F).

I got back last night and tried starting her up. Battery was very weak. The glow-plug light wouldn't come on. The only lights that were lighting on the dash were the battery light and the seat-belt light. Of course, it wouldn't crank at all.

I tried jumping the car. I connected cables and let the car sit for a few minutes. The glow-plug light on the Merc started to light up properly. It felt like it had juice, but I guess it wasn't enough. When I hit the switch, it cranked very slowly. I could actually hear the crank moving. Didn't start. It feels like there's not enough juice to get her going.

I know that the battery may become weak in cold weather, but the battery is almost brand new. Would the car drain the battery just sitting there?

Is this a battery issue or is this something more involved? I assume it's the battery because the lights started working as soon as I used the jumper cables.

I'm getting discouraged about the car. I was expecting so much from it and it keeps leaving me stranded.

Thanks in advance.