2000 Honda Accord Car stalls at idle at times. Sometimes ne

Electrical problem
2000 Honda Accord 4 cyl Two Wheel Drive Automatic 110K miles

My 2000 Honda Accord sometimes stalls at idle, or might need a jump to start. Battery 6 months, tested fine by 3 sources. Alternator tested fine by one source, bad by another. New starter. Rebuilt transmission 2 months old. Told by one source electrical short in aftermarket stereo, but I have taken the fuse out and still have the same result. Not sure if faulty torque convertor. Or if alternator or battery is intermittant. Or if something else. Any help is appreciated.