Dodge Repair: Dodge Caravan Alternator, dodge grand caravan, dodge caravan

Question
I have a 2001 Dodge Grand Caravan.  I have replaced the battery at least 4 times.  Each time I was told the alternator was fine (passed test).  Now the repair shop is telling me the alternator is not putting out constant current (something about the diodes) and it is only charging the battery to about 66%.  They want to put in a new alternator.  I think the problem has been with the car since new. Can I keep replacing batteries instead (new alternator only warrantied for 12 months).

Answer
The Chrysler alts dont put out full apms all the time the pcm will adj the load based off what the van needs at the currant time. Go to a dealer thay have better tools to diog this issue because most mormal shops base there experience off other car brans like GM and ford where there alts are charging 100% all the time.