My Car can't start on 1998 Volvo V70 XC

My Volvo V70 XC 1998 Cross-country Can't start...all the time I need to jump start it with a cable and it will start promptly but is not charging the battery...I went to advanced auto parts to buy a new batteries they told me that my batteries is good and they don't know what is the problem... and I can’t leave the engine running over night or when I am at work to avoid to jump start it. I need your help and answer please... My email is

Asked by for the 1998 Volvo V70 XC
You need a new alternator, most likely. The guys at the parts store aren't diagnostic techs, most likely, so take it to a good shop for help.