I have one of the faulty MBP batteries
My MBP was working fine; 3h - 4h battery life. Now I get 20 mins, then darkness.
Suddenly, after 20 minutes from fully charged, MBP dies —no warning, no shutdown, just STOP! Battery still has 4 lights, try restart; dies again within seconds of starting. Battery now only 1 light flashing.
I can operate on AC and battery appears to charge, but running on battery reproduces the symptoms above.
Tried resetting the PRAM, tried restting the PMU; no change
Others have the same problem.
Working on AC — planning trip to Apple dealer.
Update Scotsys are great!
First we verified that the battery was the problem — we swapped the batteries of their demo machine and my MBP (both registring "charged"; took the machines off AC, set them both to work (iTunes visualizer, no volume, no sleep); waited for their machine (with my battery) to die, which it did after 10 minutes or so.
They didn't have a stock of batteries. You don't plan to stock replacement batteries in the first years of a product line.
So they loaned me the battery from the demo model while the dud was returned to Apple for replacement.
The demo model is running on AC, without the battery.
The first replacement Scotsys got was damaged in transit, so I kept their battery until a replacement for that arrived. All went well for a few weeks, then a new disaster!