altenator problem

No -- it cannot be. The charging system is pretty basic. You say that the battery is ok and the alterantor tested ok, but the battery does not charge. Something in those 3 statements is false. Either the battery won't take a charge or the charging system is not capable of delivering the charge. You may have cable issues - excessive resistance, corrosion build up, loose fit, etc. That can contribute to a problem. But I think you'll find the battery really won't take a charge, or the alternator has an issue providing the proper amperage or regulator voltage to make it work. Good luck.

you have,nt thrown a belt?or maybe a loose belt?