OK, I am at my wit's end, and I need some input.
Here is the scenario;
1981 300SD, after several days of normal driving with AC on, lights etc. the battery will suddenly be down to below 10v and the car will not start.
This has happened three times in the past month. After getting the car started with a boost battery, and driving home about 6 miles, the battery is charged enough to last a few days. This happened last Saturday night at Walmart, and my wife drove the car around today. When I got home from work, the battery was down below 10v, not enough to start the car.

The first time this happened, I had the battery checked out at Interstate Batteries (where I purchased the battery last August 04) and they determined that the remaining reserve capacity was a little low, and the total 750CCA may be marginal for the August Texas summers, so they replaced it with a new 850CCA battery.

I went ahead and removed the alternator to have it bench-tested. I had it bench load tested at three different shops, and all three showed that the alternator was putting out at least 14 volts, and 55 amps.

Now, a couple of weeks after I replaced the battery, the starter solenoid failed. I was able to start the car a few times by tapping the solenoid. As most may know, removing the starter on a 300SD is not one of the most pleasurable tasks, so instead of replacing the solenoid alone, I replaced the whole starter/solenoid assembly. I am now feeling that I have “beat the gremlins” and feel pretty god that my problems are behind me.

Tonight, I checked the voltage at 9.75v. I then disconnected the positive lead, and checked the current draw while the car was off. As soon as I connected the battery I could see the interior lights cycle, then the radio, antenna and then down to .02 current draw after a couple of seconds. This seems low, and in-line so no clues.
Tonight I am charging the battery on a 2amp charge, and I will check for the next few days.

Thoughts?

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1980 300D
1981 300SD
1982 300D
1983 300SD