Forgive me if this has already been addressed. I'm new here and a complete dummy regarding cars.

My Volvo 240 has 2 seemingly unfixable interactive problems.

Something drains the battery. It's inconsistent. I used it until Wed at 6pm and by Thur at 9 am, it was completely dead (even the manual clock stopped). Friday same scenario (it sat all evening until morning) - started fine. Today, somewhere in between; had some juice - clock still running and dome lights on, but not enough power to crank 'er up (see below). But after 2.5 days of no use, guaranteed dead. I've now tried 3 batteries (2 new). The foreign car dealer could not find the problem (claimed the pH in the battery was bad but the new battery didn't fix it). And charged $100 for not finding it.

Problem 2 - Symptoms: on a warm day it takes many cranks to start. On a cold day, 3 minutes or more of repeated cranking before it catches. When the first 4 or so times it fires up, it stalls immediately. The mechanic said the problem is that my cold start injector is broke and that he couldn't find this $200+ replacement part. After reading a buncha forums, I'm not so sure this is the problem, but I'm in no position to guess.

This means when the battery isn't 100%, it will die in cranking before the car catches. That's why it took almost an hour 2 days ago of being connected to someone's car before I could get a jump completed.

Could the starting problems be ruining my batteries? Or do I really have 2 different interactive problems.

ANy help would be appreciated. It's getting worse, esp. in the New England cold.